Published On: Thu, May 14th, 2020

1. Quotes, Lecture, Newspaper reports from Nikola Tesla :

Jankovic borrowed from a site.

First, who was Nikola Tesla?

In 1896, at the Franklin Institute in Philadelphia, Lord Kelvin said, ” Tesla has contributed more to electrical science than any man up to his time.” After showering words of praise upon the inventor before a meeting of the Royal Society in London in 1892, Lord Rayleigh declared that Tesla possessed a great gift for electrical discovery. Fortunately, the text of Tesla’s speech has been preserved and republished.1,2,3 He was one of the earliest scientists to understand the distinction between lumped and distributed resonance and the first to patent voltage magnification by standing waves.

The unit of magnetic induction is named in honor of Tesla. It is commonly understood by power engineers that he was the inventor of the induction motor utilizing the rotating magnetic field and the AC polyphase power distribution system currently used throughout the civilized world.* However, most electrical engineers are unaware that, as late as 1943, he (not Marconi**) was recognized by the U.S. Supreme Court as having priority in the invention of “radio.” Even fewer computer scientists are aware that, when certain computer manufacturers attempted to patent digital logic gates after World War II, the U.S. Parent Office asserted Tesla’s turn-of-the-century priority in the electrical implementation of logic gates for secure communications, control systems, and robotics. As a result, a monopoly on digital logic gates was unable to be secured in the 1950s.

* Charles E Scott, past president of the AIEE has said, ” The evolution of electric power from the discovery of Faraday in 1831 to the initial great installation of the Tesla polyphase system in 1896 [at Niagara Falls] is undoubtedly the most tremendous event in all engineering history. [Electrical Engineering, August, 1943 (Vol. 62, No. 8), pp. 351-355.] ** Although it took the courts several decades to figure this out, the facts were well understood by impartial technical men of the day. Robert H. Marriott, the first president of the IRE, once said that Marconi had “. . . played the part of a demonstrator and sales engineer. A money getting company was formed, which in attempting to obtain a monopoly, set out to advertise to everybody that Marconi was the inventor and that they owned that patent on wireless which entitled them to a monopoly.” [Radio Broadcast, December, 1925 (Vol. 8, No. 2), pp. 159-162.]

Tesla served the electrical engineering profession in its highest offices. In the early 1890s, he was elected as vice-president of the American Institute of Electrical Engineers, now the Institute of Electrical and Electronics Engineers. At the time of his election, Alexander Graham Bell was its president. Tesla served two years as vice-president of the AIEE and, a decade later, one of his laboratory technicians at the Colorado Springs experiments served as the first vice-president of the Institute of Radio Engineers when it was formed in 1903. This was the now, famous consulting engineer Fritz Lowenstein. Lowenstein was the inventor of the grid biased Class A amplifier (for which he received the sum of $150,000 from AT&T in 1918), the shaped plate capacitor, and other electrical and mechanical devices. His two IRE papers, with comments on the propagation of ground waves by Zenneck and sky waves by Austin, appeared in February and June issues of the IRE Proceedings, the year of this interview. It should also be noted that Tesla was a fellow of the AIEE, the American Association for the Advancement of Science, and a dozen other professional societies. He received over 13 honorary degrees from such diverse institutions as Columbia, Yale, and the Universities of Paris, Vienna, Prague, and Sofia.

Recently, another fascinating fact about Tesla has come to light. After all these years, it is now known that he was nominated for an undivided Nobel prize in physics in 1937. Tesla’s nominator, Felix Ehernhaft, of Vienna, had previously nominated Albert Einstein for the Nobel prize.

Tesla had the remarkable talent of charming and astonishing his admirers while at the same time enraging his enemies; the phenomenon continues to the present day. It is unfortunate that, despite several current popular biographies, there still exists no definitive technical authority, other than his own scattered publications, to consult on the scientific issues of his intriguing and colorful scientific career. Consider the adulation bestowed upon him by Lord Kelvin, Hermann von Helmholtz, Sir William Crookes, Lord Rayleigh, Sir James Dewer, Robert Millikan, Sir James Fleming, B.A. Behrend, A.E. Kennally, L.W. Austin, W.H. Bragg, Ferdinand Braun, Jonathan Zenneck, E.W.E Alexanderson, J.S. Stone, Vannevar Bush, W.H. Eccles, Edwin H. Armstrong (who served as a pallbearer at Tesla’s funeral, as did Alexanderson), and notably Albert Einstein, Ernest Rutherford, Arthur Compton, and Neils Bohr. There are a number of Nobel laureates, Royal Society fellows, IEEE presidents and fellows, and university presidents in that collection. No one, since Franklin, had so stirred the scientific and engineering world.

In 1893, Thomas Commerford Martin, the third president of the AIEE (1888-1889), edited and published a remarkable collection of Tesla’s contemporary lectures. It is in print today, and a century from now it will still be considered an unparalleled classic in scientific literature to be read along with Franklin’s letters, Priestly’s history, Faraday’s researches in electricity, Maxwell’s treatise, Hertz’s electric waves, and Heaviside’s electrical papers. In 1919, 26 years after publishing the work on Tesla, Martin wrote,

” Tesla’s influence may truly be said to have marked an epoch in the progress of electrical science. Very little data, however, has been procurable that is descriptive of his later researches, and more is the pity from the historical standpoint. Tesla has not finished. The world waits expectantly for each fresh touch of his vitalizing thought upon the big electrical problem of the age.”

Unlike most of the aforementioned scientists, Dr. Tesla; for so it is appropriate to call him, had no financial support to fall back on from a faculty position or research institute. His ideas had to support themselves and him in the technical marketplace. It is not surprising, therefore, that he felt no compulsion to share further technical details in the open scientific literature of his day. For these you must dig (and dig, and dig) through the patent literature, where only enough is disclosed to make it clear to one “skilled in the art.

Readers will also be struck with Tesla’s lighter side. His sense of humor and his quick wit shine through when he describes his 1893 RF demonstration before the public at the Sixteenth Convention of the National Electric Light Association in St. Louis, where he was distinguished as honorary member: “There was a stampede in the two upper galleries and they all rushed out. They thought it was some part of the devil’s work.” (p. 87) His humor is also evident in his description of the influence that his demonstrations had upon the Royal Institution in London in 1892: “The scientists simply did not know where they were when they saw it.” (p. 95)

Tesla could also be sarcastic: “The greatest men of science have told me [the Tesla coil] was my best achievement. . . . For instance, a man fills this space with hydrogen; he employs all my instrumentalities, everything that is necessary, but calls it a new wireless system–I cannot stop it. Another man puts in here a kind of gap. He gets a Nobel prize for it. . . . The inventive effort involved is about the same as that of which a 30-year old mule is capable.” (p. 48)

Famous, or even infamous Quotes from Dr. Nikola Tesla…

On Invention: It is the most important product of man’s creative brain. The ultimate purpose is the complete mastery of mind over the material world, the harnessing of human nature to human needs.

Of all the frictional resistance, the one that most retards human movement is ignorance, what Buddha called “the greatest evil in the world.” The friction which results from ignorance can be reduced only by the spread of knowledge and the unification of the heterogeneous elements of humanity. No effort could be better spent.

Universal peace as a result of cumulative effort through centuries past might come into existence quickly — not unlike a crystal that suddenly forms in a solution which has been slowly prepared.

George Westinghouse was a man with tremendous potential energy of which only part had taken kinetic form. Like a lion in the forest, he breathed deep and with delight the smoky air of his Pittsburgh factories. Always affable and polite, he stood in marked contrast to the small-minded financiers I had been trying to negotiate with before I met him. Yet, no fiercer adversary could have been found when aroused. Westinghouse welcomed the struggle and never lost confidence. When others would give up in despair, he triumphed.

The last 29 days of the month [are] the hardest.

No matter what we attempt to do, no matter to what fields we turn our efforts, we are dependent on power. We have to evolve means of obtaining energy from stores which are forever inexhaustible, to perfect methods which do not imply consumption and waste of any material whatever. If we use fuel to get our power, we are living on our capital and exhausting it rapidly. This method is barbarous and wantonly wasteful and will have to be stopped in the interest of coming generations.

The scientific man does not aim at an immediate result. He does not expect that his advanced ideas will be readily taken up. His work is like that of a planter — for the future. His duty is to lay foundation of those who are to come and point the way.

Even matter called inorganic, believed to be dead, responds to irritants and gives unmistakable evidence of a living principle within. Everything that exists, organic or inorganic, animated or inert, is susceptible to stimulus from the outside.

Science is but a perversion of itself unless it has as its ultimate goal the betterment of humanity.

We are confronted with portentous problems which can not be solved just by providing for our material existence, however abundantly. On the contrary, progress in this direction is fraught with hazards and perils not less menacing than those born from want and suffering. If we were to release the energy of the atoms or discover some other way of developing cheap and unlimited power at any point of the globe this accomplishment, instead of being a blessing, might bring disaster to mankind… The greatest good will come from the technical improvements tending to unification and harmony, and my wireless transmitter is preeminently such. By its means the human voice and likeness will be reproduced everywhere and factories driven thousands of miles from waterfalls furnishing the power; aerial machines will be propelled around the earth without a stop and the sun’s energy controlled to create lakes and rivers for motive purposes and transformation of arid deserts into fertile land… (Nikola Tesla, “My Inventions: the autobiography of Nikola Tesla”, Hart Bros., 1982. Originally appeared in the Electrical experimenter magazine in 1919.)

We are confronted with portentous problems which can not be solved just by providing for our material existence, however abundantly. On the contrary, progress in this direction is fraught with hazards and perils not less menacing than those born from want and suffering. If we were to release the energy of the atoms or discover some other way of developing cheap and unlimited power at any point of the globe this accomplishment, instead of being a blessing, might bring disaster to mankind… The greatest good will come from the technical improvements tending to unification and harmony, and my wireless transmitter is preeminently such. By its means the human voice and likeness will be reproduced everywhere and factories driven thousands of miles from waterfalls furnishing the power; aerial machines will be propelled around the earth without a stop and the sun’s energy controlled to create lakes and rivers for motive purposes and transformation of arid deserts into fertile land… (Nikola Tesla, “My Inventions: the autobiography of Nikola Tesla”, Hart Bros., 1982. Originally appeared in the Electrical experimenter magazine in 1919.)

War cannot be avoided until the physical cause for its recurrence is removed and this, in the last analysis, is the vast extent of the planet on which we live. Only through annihilation of distance in every respect, as the conveyance of intelligence, transport of passengers and supplies and transmission of energy will conditions be brought about some day, insuring permanency of friendly relations. What we now want is closer contact and better understanding between individuals and communities all over the earth, and the elimination of egoism and pride which is always prone to plunge the world into primeval barbarism and strife… Peace can only come as a natural consequence of universal enlightenment… (Nikola Tesla, “My Inventions: the autobiography of Nikola Tesla”, Hart Bros., 1982. Originally appeared in the Electrical experimenter magazine in 1919.)

In our dynamo machines, it is well known, we generate alternate currents which we direct by means of a commutator, a complicated device and, it may be justly said, the source of most of the troubles experienced in the operation of the machines. Now, the currents, so directed cannot be utilized in the motor, but must – again by means of a similar unreliable device – be reconverted into their original state of alternate currents. The function of the commutator is entirely external, and in no way does it affect the internal workings of the machines. In reality, therefore, all machines are alternate current machines, the currents appearing as continuous only in the external circuit during the transfer from generator to motor. In view simply of this fact, alternate currents would commend themselves as a more direct application of electrical energy, and the employment of continuous currents would only be justified if we had dynamos which would primarily generate, and motors which would be directly actuated by, such currents. (Adopted from T.C. Martin, “The Inventions, Researches and Writings of Nikola Tesla,” New Work: Electrical Engineer, 1894, pp. 9-11.)

On George Westinghouse: George Westinghouse was, in my opinion, the only man on this globe who could take my alternating-current system under the circumstances then existing and win the battle against prejudice and money power. He was a pioneer of imposing stature, one of the world’s true nobleman of whom America may well be proud and to whom humanity owes an immense debt of gratitude. (Speech, Institute of Immigrant Welfare, Hotel Baltimore, New York, May 12, 1938, read in absentia.)

On Edison: If Edison had a needle to find in a haystack, he would proceed at once with the diligence of the bee to examine straw after straw until he found the object of his search. …

I was a sorry witness of such doings, knowing that a little theory and calculation would have saved him ninety per cent of his labor. (New York Times, October 19, 1931.)

On Voltaire: I had a veritable mania for finishing whatever I began, which often got me into difficulties. On one occasion I started to read the works of Voltaire when I learned, to my dismay, that there were close on one hundred large volumes in small print which that monster had written while drinking seventy-two cups of black coffee per diem. It had to be done, but when I laid aside the last book I was very glad, and said, “Never more! (Nikola Tesla, “My Inventions: the autobiography of Nikola Tesla”, Hart Bros., 1982. Originally appeared in the Electrical experimenter magazine in 1919.)

On Mark Twain: I had hardly completed my course at the Real Gymnasium when I was prostrated with a dangerous illness or rather, a score of them, and my condition became so desperate that I was given up by physicians. During this period I was permitted to read constantly, obtaining books from the Public Library which had been neglected and entrusted to me for classification of the works and preparation of the catalogues. One day I was handed a few volumes of new literature unlike anything I had ever read before and so captivating as to make me utterly forget my hopeless state. They were the earlier works of Mark Twain and to them might have been due the miraculous recovery which followed. Twenty-five years later, when I met Mr. Clemens and we formed a friendship between us, I told him of the experience and was amazed to see that great man of laughter burst into tears. (Nikola Tesla, “My Inventions: the autobiography of Nikola Tesla”, Hart Bros., 1982. Originally appeared in the Electrical experimenter magazine in 1919.)

Nikola Tesla

Letters and Newspaper reports

BY DATE Electrician – London
Dec. 17, 1892, p. 391.


In your issue of November 18 I find a description of Prof. Ewing’s high-frequency alternator, which has pleased me chiefly because it conveyed to me the knowledge that he, and with him, no doubt, other scientific men, is to investigate the properties of high-frequency currents. With apparatus such as you describe, shortly a number of experimenters, more competent than myself, will be enabled to go over the ground as yet but imperfectly explored, which will undoubtedly result in the observation of novel facts and elimination of eventual errors.

I hope it will not be interpreted as my wishing to detract anything from Prof. Ewing’s merit if I state the fact that for a considerable time past I have likewise thought of combining the identical steam turbine with a high-frequency alternator. Anch’ io sono pittore. I had a number of designs with such turbines, and would have certainly carried them out had the turbines been here easily and cheaply obtainable, and had my attention not been drawn in a different direction. As to the combination to which you give a rather complicated name, I consider it an excellent one. The advantages of using a high speed are especially great in connection with such alternators. When a belt is used to drive, one must resort to extraordinarily large diameters in order to obtain the necessary speed, and this increases the difficulties and cost of construction in an entirely unreasonable proportion. In the machine used in my recent experiments the weight of the active parts is less than SO pounds, but there is an additional weight of over 100 pounds in the supporting frame, which a very careful constructor would have probably made much heavier. When running at its maximum speed, and with a proper capacity in the armature circuit, two and a one-half horse-power can be performed. The large diameter (30 inches), of course, has the advantage of affording better facility for radiation; but, on the ether hand, it is impossible to work with a very small clearance.

I have observed with interest that Prof. Ewing has used a magnet with alternating cores. In my first trials I expected to obtain the best results with a machine of the Mordey type – that is, with one having pole projections of the same polarity. My idea was to energize the field up to the point of the maximum permeability of the iron and vary the induction around that point. But I found that with a very great number of pole projections such a machine would not give good results, although with few projections, and with an armature without iron, as used by Mordey, the results obtained were excellent. Many experiences of similar nature made in the course of my study demonstrate that the ordinary rules for the magnetic circuit do not hold good with high frequency currents. In ponderable matter magnetic permeability, and also specific inductive capacity, must undergo considerable change when the frequency is varied within wide limits. This would render very difficult the exact determination of the energy dissipated in iron cores by very rapid cycles of magnetization, and of that in conductors and condensers, by very quick reversals of current. Much valuable work remains to be done in these fields, in which it is so easy to observe novel phenomena, but so difficult to make quantitative determinations. The results of Prof. Ewing’s systematical research will be awaited with great interest.

It is gratifying to note from his tests that the turbines are being rapidly improved. Though I am aware that the majority of engineers do not favor their adoption. I do not hesitate to say that I believe in their success. I think their principle uses, in no distant future, will be in connection with alternate current motors, by means of which it is easy to obtain a constant and, in any desired ratio, reduced speed. There are objections to their employment for driving direct current generators, as the commutators must be a source of some loss and trouble, on account of the very great speed; but with an alternator there is no objectionable feature whatever. No matter how much one may be opposed to the introduction of the turbine, he must have watched with surprise the development of this curious branch of the industry, in which Mr. Parsons has been a pioneer, and everyone must wish him the success which his skill has deserved.

Nikola Tesla

The Electrical Engineer – London
Dec. 24, 1909, p. 893


Mr. Nikola Tesla has announced that as the result of experiments conducted at Shoreham, Long Island, he has perfected a new system of wireless telegraphy and telephony in which the principles of transmission are the direct opposite of Hertzian wave transmission. In the latter, he says, the transmission is effected by rays akin to light, which pass through the air and cannot be transmitted through the ground, while in the former the Hertz waves are practically suppressed and the entire energy of the current is transmitted through the ground exactly as though a big wire. Mr. Tesla adds that in his experiments in Colorado it was shown that a very powerful current developed by the transmitter traversed the entire globe and returned to its origin in an interval of 84 one-thousandths of a second, this journey of 24,000 miles being effected almost without any loss of energy.

New York Times
Dec. 8, 1915, p. 8, colt 3


He Seeks to Patent Wireless Engine for Destroying Navies by Pulling a Lever.

To Shatter Armies Also.

“Impractical,” He Says of Westerner’s Plan to Circle Country with Electric Fire.

Nikola Tesla, the inventor, winner of the 1915 Nobel Physics Prize, has filed patent applications on the essential parts of a machine the possibilities of which test a layman’s imagination and promise a parallel of Thor’s shouting thunderbolts from the sky to punish those who had angered the gods. Dr. Tesla insists there is nothing sensational about it, that it is but the fruition of many years of work and study. He is not yet ready to give the details of the engine which he says will render fruitless any military expedition against a country which possesses it. Suffice to say that the destructive invention will go through space with a speed of 300 miles a second, a manless airship without propelling engine or wings, sent by electricity to any desired point on the globe on its errand of destruction, if destruction its manipulator wishes to effect.

Ten miles or a thousand miles, it will be all the same to the machine, the inventor says. Straight to the point, on land or on sea, it will be able to go with precision, delivering a blow that will paralyze or kill, as is desired. A man in a tower on Long Island could shield New York against ships or army by working a lever, if the inventor’s anticipations become realizations.

“It is not the time,” said Dr. Tesla yesterday, “to go into the details of this thing. It is founded on a principle that means great things in peace, it can be used for great things in war. But I repeat, this is no time to talk of such things.

“It is perfectly practicable to transmit electrical energy without wires and produce destructive effects at a distance. I have already constructed a wireless transmitter which makes this possible, and have described it in my technical publications, among which I may refer to my patent 1,119,732 recently granted. With transmitters of this kind we are enabled to project electrical energy in any amount to any distance and apply it for innumerable purposes, both in peace and war. Through the universal adoption of this system, ideal conditions for the maintenance of law and order will be realized, for then the energy necessary to the enforcement of right and justice will be normally productive, yet potential, and in any moment available, for attack and defense. The power transmitted need not be necessarily destructive, for, if existence is made to depend upon it, its withdrawal or supply will bring about the same results as those now accomplished by force of arms.

Dr. Tesla then said that it would be possible with his wireless mechanism to direct an ordinary aeroplane, manless, to any point over a ship or an army, and to discharge explosives of great strength from the base of operations.

Asked to express an opinion upon the announcement last Sunday of Charles H. Harris, an electrical engineer of Los Angeles, that he would be able to surround this country with an electrical wall of fire in time of war, Dr. Tesla gave it as his opinion that Mr. Harris was not practical.

“It is hard to stamp as impossible such results as those described in the press dispatches to which you refer. Granted, however, that the project is feasible, it would take more than all the motive power obtainable in the United States to throw a wall of fire around the country. In fact, even the passage of small currents at considerable distances through air consumes a great deal of energy on account of the immense pressure required. So, for instance, in lightning discharges, energy may be delivered at the rate of billions of horsepower, though the currents are of smaller volume than those developed by electrical generators in our power houses.”

Electrical Experimenter
April, 1919, pp. 909, 914


Editor, Electrical Experimenter:

It is to be regretted that a letter address to me by Mr. J. Harris Rogers, in your care, was published in the March number of the Electrical Experimenter, although the concurrence of our views in some wireless features might have made this desirable to so wide-awake and enterprising a periodical as yours.

Mr. Rogers seems to be a very appreciative gentleman and nothing would be farther from my thoughts than to detract anything from his merit, but in a separate contribution, which I expect to prepare for your next issue, I shall express myself on this subject without prejudice and in the interest of truth. However, the article by your Mr. H. Winfield Secor on “America’s Greatest War Invention–The Rogers Underground Wireless” contains a reference to “a novel and original high frequency generator” of Mr. Rogers’ invention. May I not–to use the President’s elegant expression– call attention to the fact that this device was described by me years ago, as will be evident from the following excerpt of a communication which appeared in the Electrical Review of March 15, 1899. In speaking of circuit controllers, I said: “I may mention here, based on a different principle, which is incomparably more effective, more efficient, and also simpler on the whole. It comprises a fine stream of conducting fluid which is made to issue, with any desired speed, from an orifice connected with one pole of a generator, through the primary of the induction coil, against the other terminal of the generator placed at a small distance. This device gives discharges of a remarkable suddenness, and the frequency may be brought within reasonable limits, almost to anything desired. I have used this device for a long time in connection with ordinary coils and in a form of my own coil with results greatly superior in every respect to those obtainable with the form of your letter, make a few statements referring in such make-and-break devices in general, and various forms based on this new principle.”

I may add that a great many forms of this apparatus were constructed and employed by me for a long time, proving very convenient and useful. Water does not give particularly good results, being incapable of causing very abrupt changes, but eletrolytes have the property of diminishing enormously in resistance when they are heated and the effects are much more intense. Salts of lithium are especially efficient.


New York, February 20, 1919.

Albany Telegram
February 25, 1923


How Nikola Tesla’s Newest Invention Is to Enable Us to See the Struggles of the Arctic Explorer, the Clash of Battles and the Fantastic Lives of Unknown Millions.

Think of it, a great mechanical eye, created of finest tempered steel, endowed with electric power and seeing to all parts of the earth’ “Science, in the person of Nikola Tesla announces it as a realized achievement. It affords a fantastic picture, a superb imaginative flight for the mechanical orb will follow in principle the exquisite and flawless construction of the human eye.

Tesla, the creator, is a Nobel prize winner and the man who harnessed Niagara Falls. He describes his all-seeing eye as follows:

“My electrical eye comes as the result of years of study and experiment. Three stages mark its construction and the first two and most difficult have already been completed. I am certain that Man will soon possess this machine in completed form and will be able to see at will to any part of the earth. In planning its construction I have taken the human eye as a model and have followed the principles which nature used in developing the human eye. My mechanical eye will be one of a group of associated machines, just as the human eye is part of the body and can only function in cooperation with other parts of the body.”

Recently wireless telephony became a fact from one side of the Atlantic to the other and soon man will be able to send his voice around the earth by wireless. The arrival of Tesla’s mechanical eye will mean that the man in New York can see his business associate in Shanghai as he talks to him by wireless. The eye resting on a pivot, will be swung about and brought to bear on the explorer, fighting his way over the frozen wastes of the Arctic circle; the fiery interior of the earth will give up its secrets to the eye, and the battles of men will be revealed to all other men in their cruelty and savagery.

The eye will teach Man to understand Man. When you hear that your neighbor has been run over and injured by an automobile you express sympathy because you know him. The death of a famous film star touches the hearts of millions because they know him. But 50,000 men, women and children may starve to death in China, while newspaper readers in New York, Youngstown, Ohio, and Phoenix, Arizona, remain unmoved because the victims are only numbers. The advent of the all-seeing eye will change all that, Tesla believes. He has labored in the hope that the revealing of the secret places of the earth will unlock the secret places of the heart and help to bring mankind together in understanding and consideration.

To understand the mechanical eye and the work that has preceded it you must know something of Tesla. This tall, gaunt electrical wizard, who has made so many fantastic dreams come true, is as strange as some of his inventions.

He lives on one of the top floors of the St. Regis, one of New York’s most exclusive hotels. There he has his workrooms, mysterious places never visited by outsiders. There the eye machine rests, waiting for the day, soon to come, when Tesla asserts he will vivify it and turn it over to his fellow-men for operation.

Tesla sleeps only two hours a night and eats only two very light meals a day.

Almost all his time and energy go into the creation of electrical
inventions. He has discovered and invented a system of arc lighting, a system of alternating current power transmission, the Tesla coil or transformer, a system of transmission of power without wires, a system of wireless telegraphy and numerous other modern wonders.

Tesla believes absolutely in his mechanical eye and its workability. In planning it he has patented the same methods that have turned out so successfully with other inventions; that is, he has worked out his machine in his mind to the last detail, without planning it on paper or by means of a model.

“As in the case of my other inventions,” he explained, “there was a long period of incubation during which I turned over in my mind the idea of creating a mechanical eye. As I came to an obstruction, I would stop, put the idea away in my subconscious mind, and return to it later. Bit by bit ways of reaching the different steps of the solution were reached. They would flash suddenly from my subconscious mind, just as all my ideas for inventions have done.

“It stands to reason that man must create in time some means of seeing through substances and to any distances. He has annihilated distance in other ways and the creation of my eye will be just a part of the large plan for bringing mankind closer together.”

It is interesting to note that at about the same time that Dr. Tesla announced his invention of the mechanical eye an electrical engineer in Pasadena, California, asserted that he was able to make metals, rocks, or any opaque material luminous by means of an electrical ray, the most powerful known to man. He made no claims that the ray would penetrate great distances into the earth, but the principle is very similar to the one on which Tesla is working.

The Tesla experiments on the giant mechanical eye are thought to date back to the days when he built his mystery tower and workhouse at Shoreham, Long Island, 60 miles from New York. The tower was constructed about 20 years ago. J. Pierpont Morgan, Sr., backing Tesla in the experiment.

The tower had a circular top and had shafts running 100 feet into the earth. Near it was an experimental station filled with strange machinery. For a long period Tesla visited the station each day and had a small army of workmen at his beck and call. It was whispered that he was struggling with the problem of interplanetary communication, among other things.

This was not verified, however, and scientists and the general public could only guess the reason for the mystery tower. Then Tesla and his workmen departed one day as suddenly as they had come. A watchman stood guard over the tower and workshop for a year, then he, too, went away and the plant became known as “Tesla’s million dollar folly.” Neighborhood boys played up and down the ladder and steps of the mystery tower and finally it was sold. During the war it was torn down when the government thought there was danger of it being used as a secret wireless station by enemies of the country. Now it is believed the mystery tower not only meant an attempt on Tesla’s part to communicate with Mars, but also saw his first experiments with the mechanical eye.

Tesla will not venture to predict whether the mechanical eye will carry sufficient power to pierce the atmosphere so that man can obtain a good view of life on Mars. He believes that Mars is inhabited and that the Martians are struggling desperately to communicate with the earth.

“I have a deep conviction,” he said, “that highly intelligent beings exist on Mars. I believe they have reached a mechanical stage of civilization much more advanced than ours. However, it is quite likely that all racial distinctions and ideals have been extinguished there and life has become simply a desperate struggle for existence. The population may have been reduced to a few highly specialized individuals.

“Twenty-two years ago, while experimenting in Colorado with a wireless power plant, I obtained extraordinary experimental evidence of the existence of life on Mars. I had perfected a wireless receiver of extraordinary sensitiveness, far beyond anything known, and I caught signals which I interpreted as meaning 1–2–3–4. I believe the Martians used numbers for communication because numbers are universal.

“My discovery was announced at the time and I am living in the hope that my vision was true and will be confirmed by future generations. The use of the mechanical eye to pierce matter and distance may hasten that day.”

Dr. Tesla believes that man has stored within him the creative genius for anything he requires and that after a certain period of incubation and when the need is great enough the invention for a given need suddenly appears.

“I know,” he explained, “that I can create any machine necessary for my needs simply by putting my mind to the problem. It is easy once Nature has given you the gift for creative work. I have been able to create a system of wireless telegraphy, and wireless telephony is now a fact.”

It is also his belief, and the belief of many other famous scientists, that the sources of electrical power and light have been only scratched so far. Not only light to pierce the earth, but wireless power to govern agriculture and to obtain chemicals and even food from the air will come in the future, he predicts.

“The human being is an automatic heat machine,” he explains, “requiring for its daily functioning a supply of fuel which it takes in the form of animal and vegetable food. Now all plants and animals are directly or indirectly nourished by the soil; hence man draws his energy from the soil.

“As population increases more and more of the fuel must be supplied. And we may therefore conclude with certitude that as time goes on this precious supply will be steadily increased by intensive cultivation of every available spot. Electricity will be instrumental in this development in many ways, and power will be transmitted for tilling the ground and performing all sorts of agricultural work. Man when he goes to far corners of the earth will carry compact instruments to provide him with heat and power and with telegraphic communication.

“Electrical power will be used for accelerating many things on which we are more or less dependent; fertilizers will be obtained from the atmosphere in great quantities and all sorts of chemicals will be manufactured electrically from primary elements. But some time, after a lapse of years, a limit may be reached.

“Artificial food, manufactured by the sun’s power, may then afford relief, but it is difficult to foresee just how far the human race can make itself independent of the products of the soil. We are the results of ages of adaptation to the environment and our organs would have to be profoundly changed to enable us to exist on artificial food alone.

“However, that is a problem for the distant future. At present man has enough to do in unveiling nature’s mysteries so he can transmit power by wireless and communicate swiftly with distant parts of the earth by voice, eye and written word.”

New York American
July 6, 1930

Man’s Greatest Achievement – by Nikola Tesla

When a child is born its sense-organs are brought in contact with the outer world.

The waves of sound, heat, and light beat upon its feeble body, its sensitive nerve-fibres quiver, the muscles contract and relax in obedience: a gasp, a breath, and in this act a marvelous little engine, of inconceivable delicacy and complexity of construction, unlike any on earth, is hitched to the wheel-work of the Universe.

The little engine labors and grows, performs more and more involved operations, becomes sensitive to ever subtler influences and now there manifests itself in the fully developed being – Man -a desire mysterious, inscrutable and irresistible: to imitate nature, to create, to work himself the wonders he perceives.

* * *

Inspired in this task he searches, discovers and invents, designs and constructs, and enriches with monuments of beauty, grandeur and awe, the star of his birth.

He descends into the bowels of the globe to bring forth its hidden treasures and to unlock its immense imprisoned energies for its use.

He invades the dark depths of the ocean and the azure regions of the sky.

He peers into the innermost nooks and recesses of molecular structure and lays bare to his gaze worlds infinitely remote. He subdues and puts to his service the fierce, devastating spark of Prometheus, the titanic forces of the waterfall, the wind and the tide.

He tames the thundering bolt of Jove and annihilates time and space. He makes the great Sun itself his obedient toiling slave.

Such is the power and might that the heavens reverberate and the whole earth trembles by the mere sound of his voice.

* * *

What has the future in store for this strange being, born of a breath, of perishable tissue, yet immortal, with his powers fearful and divine? What magic will be wrought by him in the end? What is to be his greatest deed, his crowning achievement?

Long ago he recognized that all perceptible matter comes from a primary substance, of a tenuity beyond conception and filling all space – the Akasa or luminiferous ether – which is acted upon by the life-giving Prana or creative force, calling into existence, in never ending cycles, all things and phenomena.

The primary substance, thrown into infinitesimal whirls of prodigious velocity, becomes gross matter; the force subsiding, the motion ceases and matter disappears, reverting to the primary substance.

* * *

Can Man control this grandest, most awe-inspiring of all processes in nature? Can he harness her inexhaustible energies to perform all their functions at his bidding, more still – can he so refine his means of control as to put them in operation simply by the force of his will?

* * *

If he could do this he would have powers almost unlimited and supernatural. At his command, with but a slight effort on his part, old worlds would disappear and new ones of his planning would spring into being.

He could fix, solidify and preserve the ethereal shapes of his imagining, the fleeting visions of his dreams. He could express all the creations of his mind, on any scale, in forms concrete and imperishable.

He could alter the size of this planet, control its seasons, guide it along any path he might choose through the depths of the Universe.

He could make planets collide and produce his suns and stars, his heat and light. He could originate and develop life in all its infinite forms.

* * *

To create and annihilate material substance, cause it to aggregate in forms according to his desire, would be the supreme manifestation of the power of Man’s mind, his most complete triumph over the physical world, his crowning achievement which would place him beside his Creator and fulfill his ultimate destiny.

July 20, 1931, pp. 27, 28


On the occasion of his 75th birthday, Tesla talked about new developments.

“I am working now upon two things,” he said. “First, an explanation based upon pure mathematics of certain things which Professor Einstein has also attempted to explain. My conclusions in certain respects differ from and to that extent tend to disprove the Einstein Theory . . . My explanations of natural phenomena are not so involved as his. They are simpler, and when I am ready to make a full announcement it will be seen that I have proved my conclusions.

“Secondly, I am working to develop a new source of power. When I say a new source, I mean that I have turned for power to a source which no previous scientist has turned, to the best of my knowledge. The conception, the idea when it first burst upon me was a tremendous shock.

“It will throw light on many puzzling phenomena of the cosmos, and may prove also of great industrial value, particularly in creating a new and virtually unlimited market for steel.

Tesla said it will come from an entirely new and unsuspected source, and will be for all practical purposes constant day and night, and at all times of the year. The apparatus for capturing the energy and transforming it will partake both of mechanical and electrical features, and will be of ideal simplicity.

Tesla has already conceived a means that will make it possible for man to transmit energy in large amounts, thousands of horsepower, from one planet to another, absolutely regardless of distance.

He considered that nothing can be more important than interplanetary communication. It will certainly come some day, and the certitude that there are other human beings in the universe, working, suffering, struggling, like ourselves, will produce a magic effect on mankind and will form the foundation of a universal brotherhood that will last as long as humanity itself.

He received birthday greetings from Sir Oliver Lodge, Ernst Frederik Werner Alex-Anderson, Lee De Forest, John Hays Hammond, Jr., Robert Andrews Millikan, Secretary of Commerce Robert Patterson Lamond, Henry Herman Westinghouse, and many another. Their greetings indicated the hope if not the confidence that “in a few months” or “a few years” the flame of Nikola Tesla’s genius would weld one more astounding new device for mankind.

The Literary Digest
Nov. 7, 1931

No High-Speed Limit, Says Tesla

Dr. Nikola Tesla asserted in an interview with Hugo Gernsback that speeds greater than that of light, which are considered impossible by the Einstein theory of relativity, have been produced.

Stating that the Einstein theory is erroneous in many respects, Dr. Tesla stated as early as 1900, in his patent 787,412, that the current of his radio-power transmitter passed over the surface of the earth with a speed of 292,830 miles a second. According to the Einstein theory, the highest possible speed is 186,300 miles a second.

Tesla indicated knowledge of speeds several times greater than light, and had apparatus designed to project so-called electrons with a speed equal to twice that of light.

Tesla disagreed with the part of the Einstein theory which states that the mass of an object increases with its speed. The mass of a body is unalterable, contended Dr. Tesla, According to the article, “otherwise energy could be produced from nothing, since the kinetic energy acquired in the fall of a body would be greater than that necessary to lift it at a small velocity.”

Brooklyn Eagle
July 10, 1932

Tesla Cosmic Ray Motor May Transmit Power ‘Round Earth

Famed Scientist, on Eve of 76th Birthday, Says He Has Succeeded in Harnessing ‘Penetrating Rays’ to Operate Small Motive Device

by John J. A. O’Neill, Science Editor of the Eagle

“I have harnessed the cosmic rays and caused them to operate a motive device,” declared Nikola Tesla, famous scientist, in an interview last evening on the eve of his 76th birthday…

Tesla, who all his life has worked in seclusion and struggles to avoid publicity with all the vigor with which movie stars court it, permits a handful of “science writers” to violate the rules as a sort of birthday party.

It is very much of an ordeal to the tall, straight, meticulously attired gentleman whose inventions have been epoch-making and who is unable to understand why the public should be interested in him.

“Cosmic ray investigation is a subject that is very close to me. I was the first to discover these rays and I naturally feel toward them as I would toward my own flesh and blood,” said Dr. Tesla.

His statement is borne out by reference to clippings of interviews with him more than a quarter of a century ago in which he discussed “penetrating rays” and to which not much attention was given as no one was able to comprehend the nature of them as he discussed them.

“I have advanced a theory of the cosmic rays and at every step of my investigations I have found it completely justified.” said Dr. Tesla.

Not Much Power Yet

Dr. Tesla stated that the amount of power he was able to develop in the device was insignificant.

I asked him if its power output was of the same magnitude as that of Crookes’ radiometer, the device with four vanes in a glass tube that are rotated by sunlight, and which is often seen in jewelers’ windows. He stated that the power output was many thousand times that of a Crookes’ radiometer.

“The attractive features of the Cosmic rays is their constancy. They shower down on us throughout the whole 24 hours, and if a plant is developed to use their power it will not require devices for storing energy as would be necessary with devices using wind, tide or sunlight.”

Exceed Velocity of Light

“All of my investigations seem to point to the conclusion that they are small particles, each carrying so small a charge that we are justified in calling them neutrons. They move with great velocity, exceeding that of light.

“More than 25 years ago I began my efforts to harness the cosmic rays and I can now state that I have succeeded in operating a motive device by means of them.”

I was able to prevail upon Dr. Tesla to give me some idea of the principle upon which his cosmic ray motor works.

“I will tell you in the most general way,” he said. “The cosmic ray ionizes the air, setting free many charges – ions and electrons. These charges are captured in a condenser which is made to discharge through the circuit of the motor.

Hopes to Build Large Motor

“I have hopes of building my motor on a large scale, but circumstances have not been favorable to carrying out my plan.”

I asked Dr. Tesla if his plan for transmission of power between planets involved the use of cosmic rays, and he stated that the two projects have no connection whatever. He stated that he has continued his experimental work in the laboratory on the interplanetary power transmission project and is certain of its feasibility.

I also asked him if he is still at work on the project which he inaugurated in the ’90’s of transmitting power wirelessly anywhere on earth. He is at work on it, he said, and it could be put into operation.

Cited Two Principles

He at that time announced two principles which could be used in this project. In one the ionizing of the upper air would make it as good a conductor of electricity as a metal.

In the other the power would be transmitted by creating “standing waves” in the earth by charging the earth with a giant electrical oscillator that would make the earth vibrate electrically in the same way a bell vibrates mechanically when it is struck with a hammer.

“I do not use the plan involving the conductivity of the upper strata of the air,” he said, “but I use the conductivity of the earth itself, and in this I need no wires to send electrical energy to any part of the globe.”

New York Times
July 10, 1932, p. 19, c. 1

Tesla, 76, Reports His Talents at Peak. Says His New Invention, Almost Done, Will Come as “100,000 Trumpets of Apocalypse” Will Benefit Steel Trade.

Second Discovery Would Knock Down “Walls of Jericho” – Holds Interplanetary Contact Near

Nikola Tesla, dean of American Inventors, either was 76 years old yesterday or will be today (he does not know which because he was born on the stroke of midnight), and in a self-deprecatory interview last night at a midtown hotel, where he lives, he told a little of his activities of the last year and his hopes for the future.

He expects that future to be long and productive, because it is no uncommon thing for the countrymen of his birthplace, Smiljan, in the mountains of Czechoslovakia, to live to 110 or 120, and he believes that he has more energy and alertness than ever before in his life.

“I have had a very successful year,” he said with the enthusiasm of one a third of his years. “I have made two inventions, among the most important of my life.

“When they are announced, one will be like the 100,000 trumpets of the Apocalypse. The other will be less sensational, but it, too, will be important. It will be like the shout with which Joseph’s army brought down the walls of Jericho.

“I am elated. The practical success of these inventions is almost achieved. I hope to be able to make them known within the next year.”

Invention Would Aid Steel Trade

Dr. Tesla would not disclose the nature of these inventions in detail. He intimated that the more important of them had to do with molecular physics and that it would be of the utmost benefit to the steel industry.

“When applied in certain ways,” he said, “it will yield greatly improved products and obviate much waste.”

The other invention would result in a saving of energy, he said. It had nothing to do, he explained, with the problem on which he has long been working – the

tapping of a tremendous and thus far unused source of energy. He has been working on that during the last year, he said, and has made great advances both in its practical application and in the theory underlying it. As to this new source of power, he said;

“When the time is ripe I propose first to announce the scientific principles underlying it only. Later I shall show its practical application through the forms of power generating apparatus. If I succeed, the world will see machines against which the largest turbo-dynamos of today will be mere playthings.”

In response to questioning, Dr. Tesla said that one invention on which he had been working recently would permit the generation of all kinds of rays of almost unlimited intensities, and would afford a check on whether the present theories of atomic structure are true and workable or merely a fabric of the imagination.

Recalls His Youth

The inventor of the arc lighting system, of the system of alternating current power transmission, the Tesla coil, of a system of wireless communication and of wireless power transmission systems, allowed his thoughts to rove back over the beginning of his career and when he was a small boy on the Austro-Hungarian border. Then he allowed them to look into the future, in which, within the lifetime of the younger generation he is convinced there will be communication among the planets.

“When I was 9 years old,” he related, “I built a turbine in a mountain stream on my father’s land and connected it up with bolts to all sorts of machinery. I told my uncle, ‘Some day I’m going to America and I will run a big wheel at Niagara Falls.’ I had read about Niagara Falls and it fascinated me. My uncle didn’t take it seriously. ‘You’ll never see Niagara Falls,’ he told me.

“But I did come to America, and I did put a big wheel in Niagara Falls.”

Dr. Tesla, at the height of his career, designed the great power system at Niagara, and perhaps no boyhood dream ever was more tremendously filled than his.

The inventor’s conviction of many years’ standing that there is life on other planets in the solar system and that some day we will communicate with other planets has not lessened. Means of communication will readily be found, he said, and there will be no difficulty in establishing an intelligent exchange of ideas. He indicated that this might be done through some sort of television which would transmit ideas much as moving pictures tell their stories to races of diverse languages…..

“I have a sense that we are on the eve of a great revelation,” he said, speaking of the possibility of interplanetary communication. “Whether I will live to see it is a question, but you, as a younger man, will see it. And the news of it will be the greatest sensation in the world’s history..

New York Herald Tribune
September 11, 1932

Pioneer Radio Engineer Gives Views on Power Tesla Says Wireless Waves Are Not Electromagnetic, but Sound in Nature Holds Space Not Curved Predicts Power Transmission to Other Planets

by Nikola Tesla

The assumption of the Maxwellian ether was thought necessary to explain the propagation of light by transverse vibrations, which can only occur in a solid. So fascinating was this theory that even at present it has many supporters, despite the manifest impossibility of a medium, perfectly mobile and tenuous to a degree inconceivable, and yet extremely rigid, like steel. As a result some illusionary ideas have been formed and various phenomena erroneously interpreted. The so-called Hertz waves are still considered a reality proving that light is electrical in its nature, and also that the ether is capable of transmitting transverse vibration of frequencies however low. This view has become untenable since I showed that the universal medium is a gaseous body in which only longitudinal pulses can be propagated, involving alternating compressions and expansions similar to those produced by sound waves in the air. Thus, a wireless transmitter does not emit Hertz waves which are a myth, but sound waves in the ether, behaving in every respect like those in the air, except that, owing to the great elastic force and extremely small density of the medium, their speed is that of light.

Suggested Short Waves Early

Since waves of this kind are all the more penetrating, the shorter they are, I have urged the experts engaged in the commercial application of the wireless art to employ very short waves, but for a long time my suggestions were not heeded. Eventually, though, this was done, and gradually the wave lengths were reduced to but a few meters. Invariably it was found that these waves, just as those in the air, follow the curvature of the earth and bend around obstacles, a peculiarity exhibited to a much lesser degree by transverse vibrations in a solid. Recently, however, ultrashort waves have been experimented with and the fact that they also have the same property was hailed as a great discovery, offering the stupendous promise to make wireless transmission infinitely simpler and cheaper.

It is of interest to know what wireless experts have expected, knowing that wave. a few meters long are transmitted clear to the antipodes. Is there any reason that they would behave radically different when their length is reduced to about half of one meter?

Waves Go Around World

As the general knowledge of this subject seems very limited, I may state that even waves only one or two millimeters long, which I produced thirty-three years ago, provided that they carry sufficient energy, can be transmitted around the globe. This is not so much due to refraction and reflection as to the properties of a gaseous medium and certain peculiar action which I shall explain some time in the future. At present it may be sufficient to call attention to an important fact in this connection, namely, that this bending of the beam projected from a reflector does not affect in the least its behavior in other respects. As regards deflection in a horizontal plane, it acts just as though it were straight. To be explicit the horizontal deviations are comparatively slight. In a proposed ultrashort wave transmission, the vertical bending, far from being an advantage, is a serious drawback, as it increases greatly the liability of disturbance by obstacles at the earth’s surface. The downward deflection always occurs, irrespective of wave length, and also if the beam is thrown upward at an angle to the horizontal, and this tendency is, according to my finding, all the more pronounced the bigger the planet. On a body as large as the sun, it would be impossible to project a disturbance of this kind to any considerable distance except along the surface.

It might be inferred that I am alluding to the curvature of space supposed to exist according to the teachings of relativity, but nothing could be further from my mind. I hold that space cannot be curved, for the simple reason that it can have no properties.

It might as well be said that God has properties. He has not, but only attributes and these are of our own making. Of properties we can only speak when dealing with matter filling the space. To say that in the presence of large bodies space becomes curved, is equivalent to stating that something can act upon nothing. I, for one, refuse to subscribe to such a view.

Need Radio Channels

The chief object of employing very short waves is to provide an increased number of channels required to satisfy the ever-growing demand for wireless appliances. But this is only because the transmitting and receiving apparatus, as generally employed, is ill-conceived and not well adapted for selection. The transmitter generates several systems of waves, all of which, except one, are useless. As a consequence, only an infinitesimal amount of energy reaches the receiver and dependence is placed on extreme amplification, which can be easily affected by the use of the so-called three-electrode tubes. This invention has been credited to others, but as a matter of fact, it was brought out by me in 1892, the principle being described and illustrated in my lecture before the Franklin Institute and National Electric Light Association. In my original device I put around the incandescent filament a conducting member, which I called a “sieve.” This device is connected to a wire leading outside of the bulb and serves to modify the stream of particles projected from the filament according to the charge imparted to it. In this manner a new kind of detector, rectifier and -amplifier was provided. Many forms of tubes on this principle were constructed by me and various interesting effects obtained by their means shown to visitors in my laboratory from 1893 to 1899, when I undertook the erection of an experimental world-system wireless plant at Colorado Springs.

During the last thirty-two years these tubes have been made veritable marvels of mechanical perfection, but while helpful in many ways they have drawn the experts away from the simpler and much superior arrangement which I attempted to introduce in 1901. My plans involved the use of a highly effective and efficient transmitter conveying to any receiver at whatever distance, a relatively large amount of energy. The receiver is itself a device of elementary simplicity partaking of the characteristics of the ear, except that it is immensely more sensitive. In such a system resonant amplification is the only one necessary and the selectivity is so great that any desired number of separate channels can be provided without going to waves shorter than a few meters.

For this reason, and because of other shortcomings, I do not attach much importance to the employment of waves which are now being experimented with. Besides, I am contemplating the practical use of another principle, which I have discovered and which is almost unlimited in the number of channels and in the energy three-electrode tubes. This invention has been credited to others, but as a matter of fact it was brought out by me in 1892 the principle being transmitted. It should enable us to obtain many important results heretofore considered impossible. With the knowledge of the facts before me, I do not think it hazardous to predict that we will be enabled to illuminate the whole sky at night and that eventually we will flash power in virtually unlimited amounts to planets. It would not surprise me at all if an experiment to transmit thousands of horsepower to the moon by this new method were made in a few years from now.

Kansas City Journal-Post
September 10, 1933


Nikola Tesla, Starting His 78th Year, Works on Revolutionary Power Project and Also is Completing Process for Photographing Thought

by Carol Bird

Proving his theory that a man’s efficiency and accomplishments should increase, and not diminish with mellow age, Nikola Tesla, inventor, physicist, and one of the world’s leading electrical technicians, enters his seventy-eighth year busily engaged on three or four great scientific projects.

Several of these inventions or discoveries will be looked upon as “miracles” by many people, for Mr. Tesla has long been a scientist years ahead of his time, one whose advanced theories have alternately stamped him a “madman” and a wizard.

Just as people ridiculed Copernicus’ theory of the planetary system, the unenlightened jeered Tesla’s accomplishment, years ago, regarding cosmic rays. The pathfinder and the pioneer – and Mr. Tesla is both – are always condemned by the masses.

Nikola Tesla, tall, lean, with the face of an esthetic and deep-dash set eyes, whose expression denotes concentration on a canvas of work too big for most people’s comprehension, partially described a new and inexhaustible source of power he has discovered after years of research, revolutionizing modern physical science. At the same time he touched on his own reservoir of energy which makes such monumental discoveries possible at his advanced age.

How does he tap both these deep wells? What is the secret of fine health, keen mind, unusual vitality and mental force at 77, the time of life when most men are sitting in the sun with shawls over their knees or, alas’ lying beneath the sod?

Mr. Tesla is the father of the alternating system of power transmission and radio, the induction motor and Tesla coil.

Asked about his startling new scientific discoveries, one of which concerns the “photographing of thought,” which will, he maintains, bring about a tremendous social revolution, he said:

“My first and most important discovery concerns the harnessing of a new source of power, hitherto unavailable, to be developed through fundamentally novel machines of my invention.

“I am not yet prepared to dwell on the details of the project, for they must be checked before my findings can be formally announced. I have worked on the development of the underlying principles for many years. From the practical point of view of the engineer engaged in power development, the first investment will be relatively very great, but once a machine is installed it may be depended on to function indefinitely, and the cost of operation will be next to nothing.

“My power generator will be of the simplest kind – just a big mass of steel, copper and aluminum, comprising a stationary and rotating part, peculiarly assembled. I am planning to develop electricity and transmit it to a distance by my alternating system now universally established. The direct current system could also be employed if the heretofore insuperable difficulties of insulating the transmission lines can be overcome.

“Such a source of power obtainable everywhere will solve many problems with which the human race is confronted. My alternating system has been the means of harnessing 30,000,000 horsepower of waterpower, and there are projects now going on all over the world which will eventually double that amount. But, unfortunately, there is not enough water power to satisfy the present needs, and everywhere inventors and engineers are endeavoring to unlock some additional store of energy.”

Beyond adding that the new form of energy which he has been investigating many years would be available at any place in the world in unlimited quantities, and that the machinery for harnessing it would last more than 5,000 years. Mr. Tesla would say little more on the subject. Just when the power will become available for practical purposes he could not predict with any degree of precision. In a few years, perhaps, he ventured to say.

Mr. Tesla then talked of several projects on which he has been working by way of relief from too much concentration on the main piece of work. He described one of his other interests, one highly dramatic, which stirs the imagination and which, doubtless, will sound too revolutionary to most people. But it must not be forgotten, as Mr. Tesla points out, that the ideas of television and radio and airplane were scoffed at in their infancy.

“I expect to photograph thoughts,” announced Mr. Tesla calmly, in the same tone of voice that a person occupied with some trivial things in the scheme of life might announce that it was going to rain.

Continued Mr. Tesla: “In 1893, while engaged in certain investigations, I became convinced that a definite image formed in thought must, by reflex action, produce a corresponding image on the retina, which might possibly be read by suitable apparatus. This brought me to my system of television, which I announced at that time.

“My idea was to employ an artificial retina receiving the image of the object seen, an ‘optic nerve’ and another such retina at the place of reproduction. These two retinas were to be constructed after the fashion of a checkerboard with many separate little sections, and the so-called optic nerve was nothing more than a part of the earth.

“An invention of mine enables me to transmit simultaneously, and without any interference whatsoever, hundreds of thousands of distinct impulses through the ground just as though I had so many separate wires. I did not contemplate using any moving part – a scanning apparatus or a cathodic ray, which is a sort of moving device, the use of which I suggested in one of my lectures.

“Now if it be true that a thought reflects an image on the retina, it is a mere question of illuminating the same property and taking photographs, and then using the ordinary methods which are available to project the image on a screen.

“If this can be done successfully, then the objects imagined by a person would be clearly reflected on the screen as they are formed, and in this way every thought of the individual could be read. Our minds would then, indeed, be like open books..

Besides his discoveries concerning the harnessing of the new energy, television and thought photography, Mr. Tesla is working to produce a type of radio transmitter which will insure the strictest privacy in wireless communication regardless of the number of subscribers, and he is developing some important discoveries in molecular physics which will revolutionize the science of metallurgy and greatly improve metals.

After a discussion of his new scientific findings, Mr. Tesla turned to the subject of his personal source of energy and what he considers the real values of life.

“One of the most fundamental and also one of the saddest facts in human life is well brought out in a French proverb which, freely translated, means: ‘If youth had the knowledge and age the power of doing,”‘ said Mr. Tesla “our condition of body and mind in old age if merely a certificate of how we have spent our youth. The secret of my own strength and vitality today is that in my youth I led what you might call a virtuous life.

“I have never dissipated. When I was a young man I understood well the significance of that old French proverb, although I doubt that I had even heard it then. But I seem to have a clear understanding while still young that I must control my passions and appetites if I wanted to make some of my dreams come true.

“So with this in view, quite early in life I set about disciplining myself, planning out a program of living for what I considered the most sane and worthwhile life.

“Since I love my work above all things, it is only natural that I should wish to continue it until I die. I want no vacation – no surcease from my labors. If people would select a life work compatible with their temperaments, the sum total of happiness would be immeasurably increased in the world.

“Many are saddened and depressed by the brevity of life. ‘What is the use of attempting to accomplish anything?’ they say. ‘Life is so short. We may never life to see the completion of the task.’ Well, people could prolong their lives considerably if they would but make the effort. Human beings do so many things that pave the way to an early grave.

“First of all, we eat too much , but this we have heard said often before. And we eat the wrong kinds of foods and drink the wrong kinds of liquids. Most of the harm is done by overeating and under-exercising, which bring about toxic conditions in the body and make it impossible to throw off the accumulated poisons.

“My regime for the good life and my diet? Well, for one thing, I drink plenty of milk and water.

“Why overburden the bodies that serve us? I eat but two meals a day, and I avoid all acid-producing foods. Almost everyone eats too many peas and beans and other foods containing uric acid and other poisons. I partake liberally of fresh vegetables, fish and meat sparingly, and rarely. Fish is reputed as fine brain food, but has a very strong acid reaction, as it contains a great deal of phosphorus. Acidity is by far the worst enemy to fight off in old age.

“Potatoes are splendid, and should be eaten at least once a day. They contain valuable mineral salts and are neutralizing.

“I believe in plenty of exercise. I walk eight or ten miles every day, and never take a cab or other conveyances when I have the time to use leg power. I also exercise in my bath daily, for I think that this is of great importance. I take a warm bath, followed by a prolonged cold shower.

“Sleep? I scarcely ever sleep. I come of a long-lived family, but it is noted for its poor sleepers. I expect to match the records of my ancestors and live to be at least 100.

“My sleeplessness does not worry me. Sometimes I doze for an hour or so. Occasionally, however, once in a few months, I may sleep for four or five hours. Then I awaken virtually charged with energy, like a battery. Nothing can stop me after such a night. I feel great strength then. There is no doubt about it but that sleep is a restorer, a vitalizer, that it increases energy. But on the other hand, I do not think it is essential to one’s well being, particularly if one is habitually a poor sleeper.

“Today, at 77, as a result of a well regulated life, sleeplessness notwithstanding, I have an excellent certificate of health. I never felt better in my life. I am energetic, strong, in full possession of all my mental facilities. In my prime I did not possess the energy I have today. And what is more, in solving my problems I use but a small part of the energy I possess, for I have learned how to conserve it. Because of my experience and knowledge gained through the years, my tasks are much lighter. Contrary to general belief, work comes easier for older people if they are in good health, because they have learned through years of practice how to arrive at a given place by the shortest path.”

Philadelphia Public Ledger
November 2, 1933

Tesla ‘Harnesses’ Cosmic Energy

Inventor Announces Discovery of Power to Displace Fuel in Driving Machinery Calls Sun Main Source

A principle by which power for driving the machinery of the world may be derived from the cosmic energy which operates the universe, has been discovered by Nikola Tesla, noted physicist and inventor of scientific devices, he announced today.

This principle, which taps a source of power described as “everywhere present in unlimited quantities” and which may be transmitted by wire or wireless from central plants to any part of the globe, will eliminate the need of coal, oil, gas or any other of the common fuels, he said.

Dr. Tesla in a statement today at his hotel indicated the time was not far distant when the principle would be ready for practical commercial development.

Asked whether the sudden introduction of his principle would upset the present economic system, Dr. Tesla replied, “It is badly upset already.” He added that now as never before was the time ripe for the development of new resources.

While in its present form the theory calls for the development of the energy in central plants requiring vast machinery, Dr. Tesla said he might be able to work out a plan for its use by individuals.

The central source of cosmic energy for the earth is the sun, Dr. Tesla said, but “night will not interrupt the flow of the new power supply.”

New York Times
April 8, 1934, Sec. X, P. 9, c. 1

Tesla Sees Evidence Radio and Light Are Sound

An Inventor’s Seasoned Ideas

Nikola Tesla, Pointing to ‘Grevious Errors’ of the Past, Explains Radio as He Sees It at Age of 77 – He Expects Television

By Orrin E. Dunlap, Jr.

A tall, lean inventor in a cutaway walked into his skyscraper parlor thirty-three floors above the sidewalks of New York, laid his black derby on the table, opened the window and then was ready to talk about radio’s past, present and future. He wee Nikola Tesla, the inventor whose discovery of the rotary magnetic field made possible the alternating current motor. He described a system of wireless transmission of energy in 1892.

Seven milestones beyond three-score and ten, this electrical wizard, who came to America in 1884, looked back across the years, recalled where theorists often chose wrong paths at the crossroads of science and then turned his thought to the future in which television lurks.

A Spectacle That Frightens

“There is something frightening about the universe when we consider that only our senses of sound and sight make it beautiful,. said Mr. Tesla as his furrowed brow indicated he is puzzled with its destiny. “Just think, the universe is darker than the darkest ink; colder than the coldest ice and more silent than a silent tomb with all the bodies rushing through it at terrific speeds. What an awe-inspiring picture, isn’t it? Yet it is our brain that gives merely a physical impression. Sight and sound are the only avenues through which we can perceive it all. Often I have wondered if there is a third sense which we have failed to discover. I’m afraid not,” he said after some hesitation in thought.

Looking back to the mauve decade, to the turn of the century when the world was being thrilled with new ideas and discoveries, Mr. Tesla observes a vast change in the art of invention. Man, he finds, in this streamline era of speed, has little chance to think.

Fruits of Seclusion

The big, modern research laboratories are but the incubators of ideas as he has watched them function. Seldom, if ever, he explains, has an original idea of any consequence been born in an elaborate laboratory. The egg of science is laid in the nest of solitude. True, it may later be incubated, hatched and nursed in the million-dollar laboratory.

“It is providential that the youth or man of inventive mind is not ‘blessed’ with a million dollars,” said Mr. Tesla. “He would find it difficult to think. m e mind is sharper and keener in seclusion and uninterrupted solitude. No big laboratory is needed in which to think. Originality thrives in seclusion free of outside influences beating upon us to cripple the creative mind. Be alone, that is the secret of invention; be alone, that is when ideas are born. That is why many of the earthly miracles have had their genesis in humble surroundings.”

Radio experimenters of this age are following ancient theories, Mr. Tesla believes, and he warns that progress will be more rapid when they discard the old and adopt new ideas. His directions for getting on the right track of radio, television and sundry other branches of science follow:

“The fascination of the electro-magnetic theory of light, advanced by Maxwell and subsequently experimentally investigated by Hertz, was so great that even now, although controverted, the scientific minds are under its sway. This theory supposed the existence of a medium which was solid, yet permitted bodies to pass through it without resistance; tenuous beyond conception, and yet, according to some, one thousand times denser than platinum. According to our conceptions of mechanical principles and ages of experience, such a medium was absolutely impossible. Nevertheless, light was considered essentially a phenomenon bound up in that kind of a medium; namely, one capable of transmitting transverse vibrations like a solid.

A Question Tesla Asked

“It is true,” said Mr. Tesla, “that many scientific minds envisaged the theory of a gaseous ether, but it was rejected again and again because in such a medium longitudinal waves would be propagated with infinite velocity. Lord Kelvin conceived the so-called contractile ether, possessing properties which would result in a finite velocity of longitudinal waves. In 1885, however, an academic dissertation was published by Prof. De Volson Wood, an American, at a Hoboken institution, which dealt with a gaseous ether in which the elasticity, density and specific heat were determined with rare academic elegance. But, so far, everything pertaining to the subject wee purely theoretical..

What, then, can light be if it is not a transverse vibration? That was the question he asked himself and set out to find the answer.

“I consider this extremely important,. said Mr. Tesla. “Light cannot be anything else but a longitudinal disturbance in the ether, involving alternate compressions and rarefactions. In other words, light can be nothing else than a sound wave in the ether..

This appears clearly, Mr. Tesla explained, if it is first realized that, there being no Maxwellian ether, there can be no transverse oscillation in the medium.

The Newtonian theory, he believes, is in error, because it fails entirely in not being able to explain how a small candle can project particles with the same speed as the blazing sun, which has an immensely higher temperature.

“We have made sure by experiment,” said Mr. Tesla, “that light propagates with the same velocity irrespective of the character of the source. Such constancy of velocity can only be explained by assuming that it is dependent solely on the physical properties of the medium, especially density and elastic force.

Micro-Wave Possibilities

Coming now to the wireless waves, it is still true that they are of the same character as light waves, only they are not transversal but longitudinal. As a matter of fact, radio transmitters emit nothing else but sound waves in the ether, and if the experts will realize this they will find it very much easier to explain the curious observations made in the application of these waves.

“It being a fact that radio waves are essentially like sound waves in the air, it is evident that the shorter the waves the more penetrative they would be. In 1899 I produced electromagnetic waves from one to two millimeters long and observed their actions at a distance. There has been a great hope expressed by various workers that introduction of these waves will have a revolutionary effect, but I am not sharing the opinion. They will be used, of course, but to a very limited extent. It is manifest that applications of the very short waves will not produce any appreciable effect upon the wireless art.

“Errors” Retard Wireless Power

What about the possibilities of power transmission by wireless? the inquirer said.

Here again Mr. Tesla blames “a strange misconception of the experts” and “grievous errors” for retarding the idea. He believes that when it is accomplished, the power will travel on long waves and not on the wings of “uneconomically produced” short waves. He said he could vouch that the scheme of wireless power transmission is entirely practical.

“m e application of short waves for power purposes,” said Mr. Tesla, “involves complicated and expensive apparatus for rectification or frequency transformation, which would make any serious attempt to carry out a project of this kind much more difficult from an economical point of view.”

When will television come around the corner? he was asked.

“It ought to be with us soon, and some day it will be on a par of perfection with broadcasting of music.. Then with a circular sweep of his arm and added, “there will be large pictures thrown on the wall..

New York Sun
July 10, 1934


Tesla Describes His Beam of Destructive Energy

Invention of a “beam of matter moving at high velocity” which would act as a “beam of destructive energy” was announced today by Dr. Nikola Tesla, the inventor, in his annual birthday interview. Dr. Tesla is 78, and for the past several years has made his anniversary the occasion for announcement of scientific discoveries.

The beam, as described by the inventor to rather bewildered reporters, would be projected on land from power houses set 200 miles or so apart and would provide an impenetrable wall for a country in time of war. Anything with which the ray came in contact would be destroyed, the inventor indicated. Planes would fall, armies would be wiped out and even the smallest country might so insure “security. against which nothing could avail.

Dr. Tesla announced that he plans to suggest his method at Geneva as an insurance of peace.

New York Sun
July 11, 1934


Dr. Tesla Says Two of Four Necessary Pieces of Apparatus Have Been Built

Amplifying his birthday anniversary announcement of the prospective invention of an electrical death-ray, or force beam, that would make any country impregnable in time of war, Dr. Nikola Tesla says that two of the four pieces of necessary apparatus already have been constructed and tested.

Four machines combine in the production and use of this destructive beam, which, according to Dr. Tesla would wipe out armies, destroy airplanes and level fortresses at a range limited only by the curvature of the earth. These four are:

First, apparatus for producing manifestations of energy in free air instead of in a high vacuum as in the past. This, it is said, has been accomplished.

Second, the development of a mechanism for generating tremendous electrical force. This, too, Dr. Tesla says, has been solved. The power necessary to achieve the predicted results has been estimated at 50,000,000 volts.

Third, a method of intensifying and amplifying the force developed by the second mechanism.

Fourth, a new method for producing a tremendous electrical repelling force. This would be the projector, or gun of the invention.

While the latter two elements in the plan have not yet been constructed, Dr. Tesla speaks of them as practically assured. Owing to the elaborate nature of the machinery involved, he admits it is merely a defense engine, though battleships could be equipped with smaller units and thus armed could sweep the seas.

In addition to the value of this engine for destruction in time of war, Dr. Tesla said it could be utilized in peace for the transmission of power. He had not developed ideas for receiving apparatus capable of transforming the destructive beam into work units, but considered this merely a matter of detail. No suggestion was made of what might happen if an enemy power obtained possession of one of these receiving outfits, and when attacked by the destructive beam simply put it to work in factories manufacturing munitions or uniforms.

Another addition to the anniversary message of the famous inventor was a positive declaration that he expected soon to construct apparatus that would disprove the theories of modern astronomers that the sun gradually was cooling off and eventually the earth would be unable to sustain life, as it would grow too cold.

New York Times
July 11, 1934, p. 18, c. 1


Invention Powerful Enough to Destroy 10,000 Planes at 250 Miles Away, He Asserts Defensive Weapon Only Scientist, In Interview, Tells of Apparatus That He Says Will Kill Without Trace

Nikola Tesla, father of modern methods of generation and distribution of electrical energy, who was 78 years old yesterday, announced a new invention, or inventions, which he said, he considered the most important of the 700 made by him so far.

He has perfected a method and apparatus, Dr. Tesla said yesterday in an interview at the Hotel New Yorker, which will send concentrated beams of particles through the free air, of such tremendous energy that they will bring down a fleet of 10,000 enemy airplanes at a distance of 250 miles from a defending nation’s border and will cause armies of millions to drop dead in their tracks.

“Death-Beam” is Silent

This “death-beam,” Dr. Tesla said, will operate silently but effectively at distances “As far as a telescope could see an object on the ground and as far as the curvature of the earth would permit it.” It will be invisible and will leave no marks behind it beyond its evidence of destruction.

An army of 1,000,000 dead, annihilated in an instant, he said, would not reveal even under the most powerful microscope just what catastrophe had caused its destruction.

When put in operation Dr. Tesla said this latest invention of his would make war impossible. This death-beam, he asserted, would surround each country like an invisible Chinese wall, only a million times more impenetrable. It would make every nation impregnable against attack by airplanes or by large invading armies.

But while it will make every nation safe against any attack by a would-be invader, Dr. Tesla added, the death-beam by its nature could not be employed similarly as a weapon for offense. For this death-beam, he explained, could be generated only from large, stationary and immovable power plants, stationed in the manner of old-time forts at various strategic distances from each country’s border. They could not be moved for the purposes of attack.

An exception, however, he added, must be made in the case of battleships, which, he said, would be able to equip themselves with smaller plants for generating the death-beam, with enough power to destroy any airplane approaching for attack from the air.

Battleships to Be Supreme

The net result of the latter, Dr. Tesla said, will be to establish the supremacy of the battleship over the airplane, and to make the nation with the largest and best equipped battleships supreme over the seas. Submarines would become obsolete, he asserted, as methods for detecting them are so perfected that no advantage is gained by submerging. And once found, he added, the death-beam could be employed to do its work of destruction under water, though not as effectively as in the air.

The production of the death-beam, Dr. Tesla said, involves four new inventions, which have not been announced by him. The scientific details of these inventions are to be given out by him before the proper scientific bodies in the near future. In the meantime he gave out a general statement outlining their nature.

The first invention, he said, comprises a method and apparatus for producing rays and other manifestations of energy in free air, eliminating the high vacuum necessary at present for the production of such rays and beams.

The second is a method and process for producing “very great electrical force.

The third is a method for amplifying this process in the second invention. The fourth, he said, is “a new method for producing a tremendous electrical repelling force.”

The voltages to be employed in propelling the death-beam to their objective, Dr. Tesla said, will attain the lightning-like potential of 50,000,000 volts. With this enormous voltage, hitherto unattained by manmade means, microscopic particles of matter will be catapulted on their mission of defensive destruction, Dr. Tesla asserted.

New York Herald Tribune
July 11, 1934, pp. 1, 15


Death Ray Also Available as Power Agent in Peace Times, Inventor Declares

By Joseph W. Alsop, Jr.

Dr. Nikola Tesla, inventor of polyphase electric current, pioneer in high frequency transmission, predecessor of Marconi with the wireless, celebrated his seventy-eighth birthday yesterday by announcing his invention of a beam of force somewhat similar to the death ray of scientific romance.

It is capable, he believes, of destroying an army 200 miles away; it can bring down an airplane like a duck on the wing, and it can penetrate all but the most enormous thicknesses of armor plate. Since it must be generated at stationary power plants by machines which involve four electrical devices of the most revolutionary sort, Dr. Tesla considers it almost wholly a defensive weapon. In peace times, he says, the beam will also be used to transmit immense voltages of power over distances limited only by the curvature of the earth.

As an hors d’oeuvre to this Jules Vernean announcement, Dr. Tesla disclosed that he has lately perfected instruments which flatly disprove the present theory of the high physicists that the sun is destined to burn itself out until it is a cold cinder floating in space. Dr. Tesla stated that he is able to show that all the suns in the universe are constantly growing in mass and heat, so that the ultimate fate of each is explosion.

Dr. Tesla refused to describe specifically the instruments in question in both discoveries, or even to disclose the principles upon which they are built. He said that at some date soon he expected to make the full details public in scientific journals or before scientific bodies. Since he considers the beam of force a defensive and therefore a pacifist weapon, he hopes to be able to present it in full for the first time at the disarmament conference at Geneva. He also said that minor parts of each of the discoveries are still in the theoretical, or blueprint stage, but he pointed out that his method of work has almost always been purely mental.

The aging inventor, a tall, thin, almost spiritual figure in the sort of brown cutaway suit that older men wore before the World War, received interviewers in one of the public rooms in the Hotel New Yorker, where he lives. Before he would speak of his present work he reviewed his past achievements, which entitle him more than Edison, Steinmetz or any other, to be called the father of the power age. He has 700 patents to his credit and not a few of them are for epoch-making discoveries, but over and over again he has been ridiculed as a lunatic. He recalled this and his work together as if to prepare the way for his announcements.

He came to the idea of a beam of force, he said, because of his belief that no weapon has ever been found that is not as successful offensively as defensively. m e perfect weapon of defense, he felt, would be a frontier wall, impenetrable and extending up to the limits of the atmosphere of the earth.

Creates Rays in Free Air

Such a wall, he believes, is provided by his beam of force. It is produced by a combination of four electrical methods or apparatuses. First and most important is a mechanism for producing rays and other energy manifestations in free air. Hitherto vacuum tubes have always been necessary. Second is an apparatus for producing unheard-of quantities of electrical current and for controlling it when produced. The current is necessary as power for the first mechanism. Without this, no rays of sufficient strength could be produced. The third is a method of intensifying and amplifying the second process, and the fourth is a method of producing “tremendous electrical repellent force.”

“These four inventions in combination enable man to loose in free air forces beyond conception,” Dr. Tesla remarked mildly. “By scientific application we can project destructive energy in thread-like beams as far as a telescope can discern an object. The range of the beams is only limited by the curvature of the earth. Should you launch an attack in an area covered by these beams, should you, say, send in 10,000 planes or an army of a million, the planes would be brought down instantly and the army destroyed.

“The plane is thus absolutely eliminated as a weapon; it is confined to commerce. And a country’s whole frontier can be protected by one of the plants producing these beams every 200 miles. Nor should they be much more costly than an ordinary power plant..

It Is an Electric Gun

The beam of force itself, as Dr. Tesla described it, is a concentrated current – it need be no thicker than a pencil – of microscopic particles moving at several hundred times the speed of artillery projectiles. The machine into which Dr. Tesla combines his four devices is, in reality, a sort of electrical gun.

He illustrated the sort of thing that the particles will be by recalling an incident that occurred often enough when he was experimenting with a cathode tube. Then, sometimes, a particle larger than an electron, but still very tiny, would break off from the cathode, pass out of the tube and hit him. He said he could feel a sharp, stinging pain where it entered his body, and again at the place where it passed out. The particles in the beam of force, ammunition which the operators of the generating machine will have to supply, will travel far faster than such particles as broke off from the cathode, and they will travel in concentrations, he said.

As Dr. Tesla explained it, the tremendous speed of the particles will give them their destruction-dealing qualities. All but the thickest armored surfaces confronting them would be melted through in an instant by the heat generated in the concussion.

Some Parts Still Unmade

Such beams or rays of particles now known to science are composed always of fragments of atoms, whereas, according to Dr. Tesla, his would be of microscopic dust of a suitable sort. The chief differentiation between his and the present rays would appear to be, however, that his are produced in free air instead of in a vacuum tube. The vacuum tube rays have been projected out into the air, but there they travel only a few inches, and they are capable only of causing burns or slight disintegration of objects which they strike.

Dr. Tesla declared that the two most important of the four devices involved in his force beam generator, the mechanism for producing rays in free air and the mechanism for producing great quantities of electrical current had both been constructed and demonstrated by actual experiments. The two intensifying and amplifying apparatuses are not yet in existence but he displayed the most perfect confidence that when they are, they will work as he expects them to do.

“These effects,. he said, “are of the kind that can be calculated with the most positive accuracy. Like many other things I have done they require no previous experiment once they are properly conceived. There are a few details to be finished – my calculation might be perhaps 10 per cent off at present – and then the whole thing will be presented to the world. It has always been my practice to give the world a sort of preview of what I am doing so that a reception is prepared.”

“I should also say, and this is perhaps as important as anything else about it, that in this apparatus all limitations as to electric force and the quantity of electricity transmitted have been removed.”

It was evident that Dr. Tesla’s work on the force beam as a peace-time means of power transmission was far less advanced than his work on it as a defensive weapon. He did not describe the nature of the receiver which will transform the force beam into useful power, though he declared that he had designed one, nor was he able to show just how the dangers of having such death-dealing but invisible beams traveling through the air could be surmounted.

Dr. Tesla was far less definite in his description of the experiments which led to his revolutionary prediction of the future of the sun and its system than he was when talking of the force beam. He had, he said, detected “certain motions in the medium that fills space, and measured the effects of these motions.. The results of the experiments had led his “inescapably” to the conclusion that such bodies as the sun are taking on mass much more rapidly than they are dissipating it by the dissipation of energy in heat and light.

“Heat to Kill All Peoples”

He pointed out that his theory means a future for the earth as different from the general belief as the future of the sun. It is generally held that life on the earth will cease when the sun grows so cold that the earth temperature drops to a point where life can no longer be supported. Dr. Tesla prophesies that life on the earth will cease because the planet will grow too warm to support life, and he believes that life will then begin on outer planets now too cold. He said that his discovery not only allowed him to predict a very different future for the heavenly bodies from that now generally expected for them, but also to calculate in a new way their age.

Nor were these two discoveries, of a force beam and a new future for the universe, the only new things Dr. Tesla had to offer. The completely new and unlimited source of energy which he stated he was at work on is, he said, still under examination by him. Since he first spoke of it great strides have been made, and the complete announcement of it is to be expected in a comparatively short time.

Finally there was the electric bath. The idea of a bath of electricity to cleanse the person far more completely than water ever could has always been at the back of Dr. Tesla’s mind. Many years ago he built a machine which performed the function successfully, but, because it cost too much and was not without its dangers, he dropped it as impractical. Lately he has improved it so much that he feels it is now fit for general use.

Works Twenty Hours Daily

“You may think this is a lot of work for an old man like me to have on his hands,. he said with a little smile. “You may think I have too many big things – I have told you three – on my hands. But I have worked for sixty years now, and I have such a store of ideas that I can see clearly. I have concentrated on my subject. My brain works better now than it ever did when I was a young man. I am capable of far more than I was in what they call ‘your prime.”‘

He smiled again. The white, parchmenty skin, drawn tight over a finely built bony structure, creased round his eyes and mouth. He admitted to being a little thinner than last year, but, he explained, every one dries up, as time goes on, and there is nothing in being thin that can interfere with work.

He was asked a question about birthday celebrations and congratulations. He had received congratulations from all over the world, he said, but the one which pleased him most was from his sister in Jugoslavia, Mrs. Marica Kosanovic, who is three years younger than he and “the smartest in all our family.” He talked for a while of his family, recalling all the inventors there were – five recorded – and students in his ancestry.

“As for celebration,” he added, “my only celebration is a little work, and these small disclosures of results.”

New York World Telegram
July 24, 1934


By Nikola Tesla.

I am a reader of your excellent paper and frequently preserve excerpts of interest to me for future reference.

One of these is an article by William Engle, in your issue of June 29, 1934, dealing with hydro-electric development in which the author characterizes my recent announcement of a new inexhaustible source of power as “nebulous.”

A preliminary information is necessarily incomplete, but I always make sure that it is based on demonstrated fact and accurate as far as it goes. My illustrious namesake, Copernicus, used to go twenty times over his scientific statements before giving them out; nevertheless, compared with the attention I bestow upon my own, he might have been considered a careless man.

The author of the article gives an eloquent account of water power development, recalling vividly to my mind the almost miraculous way in which success with my alternating system was achieved. As I review the past, I realize how fortunate it was that at the time when, after years of fruitless talking to deaf ears, I finally managed to be heard by a few, there was a man in the electrical industry towering above all others, like Samson over the Philistines. A genius of the first degree, inventive ability and mastery of business, a man truly great, of phenomenal powers – George Westinghouse. He espoused my cause and undertook to wage a war against overwhelming odds.

The alternating current was completely discredited, decried as deadly and of no commercial value. Edison thought that the wires might be used for hanging laundry to dry. Steinmetz had a very poor opinion of my induction motor. The old interests were powerful and resolved to fight any encroachment on their business by all means fair or foul. But Westinghouse was not dismayed and threw all his energy and resources into the battle of the century. More than once he came near to being snuffed out, but finally he routed his opponents and put the new industry on a firm foundation. It was a monumental achievement unparalled in the history of technical development. The service he rendered to the world is beyond estimate.

But it took another human dynamo, a genius of a different kind – Samuel Insull – to enlarge on the work of Westinghouse and apply the system on a colossal scale. Insull concentrated his efforts on cheapening the production, transmission and distribution of power. He recognized early the economic advantages of large units and prevailed upon the manufacturers to supply him with huge turbo-generators, regardless of cost. He introduced other improvements raising the efficiency and range of central stations and finally realized, practically and successfully, the Super Power System which I had barely suggested in 1893. The results he obtained were such as to astonish engineers, and his bold example was quickly followed here as well as in other countries, saving immense sums of money to the consumers.

At present the work of Westinghouse and Insull is carried further in every corner of the globe, providing new resources, transforming cities and communities and contributing to the safety, comfort and convenience of hundreds of millions. Let us thank the stars that these great pioneers lived in our time, as otherwise we might have had to wait a century for the benefits we now enjoy.

Another item of interest to me is your flattering editorial of July 12, 1934, with a fly in the ointment since you state that examination of performance does not in recent cases fulfill my prophecy. Perhaps not, but on the whole I have been extraordinarily successful. You would be surprised to know how many of my discoveries and inventions are in extensive use. To give an illustration, I may refer to my wireless system of transmission of energy which is looked upon by many as a pipe dream.

These uninformed people should be told that “wireless” is not a single invention but an art involving the use of many of them, and of them I have contributed the fundamental and most essential, and they are universally employed. There is as yet no pressing necessity for wireless transmission of power in industrial amounts, but as soon as it arises the system will be applied and with perfect success.

Still another item which has interested me is a report from Washington in the World-Telegram of July 13, 1934, to the effect that scientists doubt the death ray effect. I am quite in agreement with these doubters and probably more pessimistic in this respect than anybody else for I speak from long experience.

Rays of the requisite energy can not be produced, and then, again, their intensity diminishes with the square of the distance. Not so the agent I employ, which will enable us to transmit to a distant point billions of times more energy than is possible by any kind of ray.

We are all fallible, but as I examine the subject in the light of my present theoretical and experimental knowledge I am filled with deep conviction that I am giving to the world something far beyond the wildest dreams of inventors of all time.

New York.

Every Week Magazine
Oct. 21, 1934, p. 3


By Helen Welshimer

“America Enters War !” “United States Joins Allies “‘ “Congress Declares War!. The newsboys were screaming the headlines through the rainy April night. Men and women stood on corners, talking, talking, talking

The drift of the days went on. Troop trains pulled out of the stations, from Centreville, Mississippi, up to Bangor, Maine. The drums throbbed and the trumpets blew. The ships sailed and the casualty lists came back. One by one the gold stars replaced the white

And 1917 drifted into 1918.

Dr. Nikola Tesla was in his laboratory trying hard to solve a problem of ages. Once in a while he raised his head to listen. Then he turned back to his experiments. He was going to end war’

The noted inventor, 78 years old now, already had 700 inventions to his credit. This was to be his greatest.

Years marched on. The fanfare and the drums were done. The dead were buried. The living came home.

Now, 15 years after the war has ended, Tesla, one of the greatest inventors of all time, has announced that his invention to end all wars, by a perfect means of defense which any nation can employ, is ready. Soon, he says, he will take it to Geneva to present it to the Peace Conference.

Whether it is a dream or reality may soon be known. He claims to have created a new agent, silent and invisible, which kills without trace and yet pierces the thickest armor. It is a beam of death and destruction formed of minute particles of matter carrying such tremendous energy that they could bring down a fleet of 10,000 attacking planes and wipe out an army of millions at a distance of 250 miles.

“The invention,” said Dr. Tesla, “will make war impossible for it will surround any country using this means with an impenetrable, invisible wall of protection. Plants for the generating of this beam will be erected along the coasts and near cities. One plant will afford perfect safety within an area of 40,000 square miles.

“The beam will be effective at any distance at which the object to be destroyed can be perceived through a telescope. Every country will have to adopt this invention, for without it a nation will be helpless.

“The beam, intended chiefly for defense, will be projected from an electric power plant, ready to be put in action at the first sign of danger. The cost of operation will be insignificant, as the plant is chiefly intended for use in emergency. But to make the investment profitable in times of peace it may be commercially employed for a number of purposes.”

Dr. Tesla wishes it to be understood that the means he has perfected has nothing in common with the so-called “death ray.”

“It is impossible to develop such a ray. I worked on that idea for many years,” he says, “before my ignorance was dispelled and I became convinced that it could not be realized. This new beam of mine consists of minute bullets moving at a terrific speed, and any amount of power desired can be transmitted by them. The whole plant is just a gun, but one which is incomparably superior to the present..

The picture of the protected world, in which men will devote their time in pursuits of peace, is a strangely fascinating one.

Imagine the map of the world, every country surrounded by great plants which will offer absolute protection to the nation itself and instant death to any intruders. Only ships flying white flags of peace can sail into a foreign harbor.

The power plants, resembling forts placed at strategic distances along a country’s border, will be on guard. As they are immovable, they will constitute essentially means for defense, and by making invasion impossible will greatly advance the cause of peace.

If, occasionally, nations decide that they must have war just for the thrill of a throbbing drum and a singing bugle, it can be staged on the sea, Dr. Tesla says. Navy supremacy will banish aircraft.

“The airplane will cease to be used as a means of offense,” the great inventor explains. “It will be used entirely for peace, as it should be. An airplane, through the very nature of its construction, can not carry with it a generating plant for the beam. If it comes in contact with a country which is protected, it has no chance.

“The battleships will ride to sea safe from air raids, for they will be equipped with smaller plants for generating a beam of sufficient power to destroy ‘any attacking airplane. But they will not be permitted to come near the shore of a protected country and attack it with any chance of success.

“The nation which has the best equipped battleships, however, will gain the supremacy of the seas. Submarines will be obsolete, for the methods of detecting them will be perfected to such a degree that there will be no longer any advantage in submerging. When a submarine is located the beams will function under water, though not quite so effectively as in air.”

Four new inventions of Dr. Tesla are involved in the creation of the beam.

“Briefly, the first comprises a method and apparatus for producing rays and other manifestations of energy in free air, eliminating the high vacuum heretofore indispensable,- he explains.

“The second one is the process for producing electrical force of immense power.

“The third method amplifies the process, and the fourth produces a tremendous electrical repelling force.”

In times of peace such a plant can be used to transmit power in any amount up to its full capacity and to any place on the earth visible through a telescope, according to its inventor. Voltages never before attained, of 50,000,000 volts or more, will have to be applied.

The man who is responsible for so many discoveries and improvements has devoted his entire life to his scientific pursuits. Tall, lean, reserved, his path goes between the two small laboratories and the various manufacturing plants with which he has contact.

Born in Yugoslavia, Tesla comes from a race of inventors.

“On my mother’s side, for three generations, almost all members of the families were inventors,” he says. “My mother was Georgianna Mandic, who was noted as an inventor of household appliances. One of the things which she perfected was her own weaving machine.

“Her family can be traced back to the seventh century, in the historical records. My grandfather was an officer in Napoleon’s army.”

Tesla began to invent at the age of six. As he grew up his interest focused in the laboratory.

“I sleep about one and one-half hours a night,” the inventor says. “I think that is enough for any man. When I was young I needed more sleep. But age doesn’t require so much. There are so many things to do I do not want to spend time sleeping needlessly. In my family all were poor sleepers. Time spent in sleep is lost time, we always felt.”

Tesla, busy with his 700 inventions, never had time for marriage. He never had a girl in his young days. He never had a romance. There was no leisure for them.

His diet is simple. He lives chiefly on vegetables, cereals and milk. The menu includes onions, spinach, celery, carrots, lettuce, with potatoes occasionally. Whites of eggs and milk complete the diet. There is no meat on his vegetable plate. He never smokes or tastes tea, coffee, alcoholic beverages or any other stimulant.

While he is perfecting the beam which will defend nations from attack, the inventor is playing with other ideas. He goes from one to the other, he says, as this or that gains paramount interest or some new clue is suggested.

“But what is giving me more fun than anything I have done for a long, long time,” Dr. Tesla explains, “is an electric bath which I hope to have ready for general use very soon.

“It doesn’t require much room. There is a platform on which the person stands. He turns on the current. Instantly all foreign material such as dust, dandruff, scales on the skin and microbes is thrown off from the body. The nerves, too, are exhilarated and strengthened. The ‘bath’ is excellent for medical as well as for cleaning purposes..

However, the war picture gives the master inventor more satisfaction than the minor inventions. He is rejoicing because his instrument of death will save millions of lives and inestimable property.

His only regret is that there may be another war before the discoveries he has made have been placed before the Disarmament Conference at Geneva, and generally adopted by the nations of the world.

“The next war, and I am afraid that there will be one before long,” he says, “will be fought in the air. But if the beam is adopted war in the air will cease.

“Whatever battles there are thereafter will be confined to the sea. But no nation will dare to attack another nation when every country is armed. There will be a general feeling of safety throughout the world.”

New York Herald Tribune
June 5, 1935


Scoffs at Normandic “Speed”

Sees success for His Plan to Use Stratosphere Ray

Would Light Sea at Night

Says French Liner’s System Copied His in U. S. Boats

Dr. Nikola Tesla, scientist and seer whose discoveries in the fields of polyphase electrical current and wireless place him in the front rank of modern inventors, refused yesterday to be awed by the record speed achievement of the French liner Normandie in crossing the Atlantic in 4 days 11 hours 42 minutes and predicted that enormous ships would cross the ocean at far greater speeds by means of a high-tension current projected from power plants on shore to vessels at sea through the upper reaches of the atmosphere.

In his room at the Hotel New Yorker, dressed in a blue bathrobe, blue socks and red slippers, Dr. Tesla expounded the principles of his fabulous method of power transmission – a method which he has been developing at irregular intervals from as far back as 1897. The virtues of stratosphere transmission, he said, lay not only in its potential increase of a vessel’s speed but also in its power to eliminate the dangers of nocturnal navigation.

In short, high-tension currents of electricity passing through the stratosphere would light the sky and to a degree turn night into day. With power plants stationed at intermediate posts such as upon the Azores and Bermuda, vessels could cross the Atlantic, propelled and safeguarded at the same time by electricity generated ashore. There would no longer be danger of boiler explosions nor hazards of collisions at sea. Even on moonless, cloudy nights, there still would gleam overhead the faint rays of surging electrical currents, so strong that pilots would be able to distinguish objects miles away.

Normandie Uses U. S. Cruiser System

Dr. Tesla, a tall, slender man with straight silvery hair, lean features and bright blue eyes that belie his seventy-eight years, prefaced his prophecies by pointing out that the Normandie’s system of power generation and application was not new – but one which had been adopted long ago in some of the United States cruisers. The principle is one of his own invention.

“The Normandie,. he said, “employs an ‘electric drive’ in which turbines drive generators and generators supply the current to independent motors. In this case the turbines are driven by steam, the generators are of the three-phase type and the motors are of the induction type.

In many respects the machinery installed on the United States cruisers by former Secretary Josephus Daniels is more remarkable than that on the Normandie on account of the limitations of available space. Moreover, while the Normandie develops only 160,000 horsepower, the cruisers each develop 185,000 horsepower. These cruisers employ the most remarkable engine plants in the world, and I believe that this drive would not have been employed on the Normandie had it not been for the pioneering work done in the United States.

“In view of the adoption on such a large scale of these inventions of mine, it is interesting to recall that I was violently attacked only a few years ago by a professor of marine engineering at Columbia, who claimed the electrical drive was not feasible and that it was folly to undertake it.

“However splendid the machinery on the Normandie might be, the time is not distant when we will have much simpler and better means of propulsion.”

Cites His Force Beam as One Way

Here Dr. Tesla recalled the possibilities of his force beam of particles which he announced last year as a potential defensive weapon of great value. One of its aspects is a death ray capable of destroying airplanes and armies. Another is a means of power transmission which could be used to relay immense voltages of power over distances limited only by the curvature of the earth.

The difficulties inherent in using this method as a means of propulsion for oceangoing ships, however, were seen by Dr. Tesla to lie in the necessity of vast outlays of capital and concerted harmonious endeavor by the chief nations of the world. The latter, he said, would be impossible to achieve at the present time. A third difficulty would be the task of keeping a ship at sea constantly in touch with a threadlike beam of particles from ashore.

Dr. Tesla, therefore, suggested that his other scheme, of stratosphere transmission of electricity, would be a far more feasible means of marine propulsion. The principles of the two plans are entirely distinct. The force beam is a thin barrage of tiny particles discharged at tremendous velocities from a kind of electrical gun. The other invention, which he has not hitherto discussed publicly, is of transmitting high tension currents through the upper air, and receiving them by means of a vertical ionizing beam which would be a sort of invisible electrode. He discussed this yesterday:

Started New Idea in 1897

“There is a method of conveying great power to ships at sea which would be able to propel them across oceans at high speed. This method I conceived between 1897 and 1899, and in Colorado Springs in 1899 I made experiments along this line on a large scale.

“The principle is this: A ray of great ionizing power is used to give to the atmosphere great powers of conduction. A high tension current of 10,000,000 to 12,000,000 volts is then passed along this ray to the upper strata of the air, which strata can be broken down very readily and will conduct electricity very well.

“A ship would have to have equipment for producing a similar ionizing ray. The current which has passed through the stratosphere will strike this ray, travel down it and pass into the engines which propel the ship.

Pet Scheme to Light Ocean

“I will confess that I was disappointed when I first made tests along this line on a large scale. They did not yield practical results. At the time I used about 8,000,000 to 12,000,000 volts of electricity. As a source of ionizing rays I employed a powerful arc reflected up into the sky. At the time I was trying only to connect a high tension current and the upper strata of the air, because my pet scheme for years has been to light the ocean at night.

“However, since 1902 I have made many improvements in my method which I know now will assure success. A power plant upon the Azores, for instance, could send a current up into the stratosphere and illuminate the sky sufficiently for pilots to discern objects upon the ocean at a safe distance.”

Dr. Tesla said that he was working constantly every day to perfect his force beam, his method of stratosphere transmission of power, and a number of other inventions the nature of which he was not ready to disclose. When it was called to his attention that he was working pretty hard for a man who would be seventy-nine years old next month, he replied:

“Why, I’m young. I never think of my age. Really, you know, I’m just a youngster..

New York Sun
July 9, 1935


Famous Scientist to Tell Them Tomorrow

Nikola Tesla, physicist and inventor, will have not one but three startling discoveries to announce at a press luncheon on the occasion of his seventy-ninth birthday tomorrow, he said today at the Hotel New Yorker.

Mr. Tesla said that one of these discoveries is a new way of transmitting energy, an entirely new principle nothing like wireless. The second has to do with a new method of housing cosmic rays, and the third concerns a problem which scientists and inventors have worked on for seventy-five years but which every one has given up as utterly impossible.

New York World-Telegram
July 11, 1935


Could Destroy Empire State Building with Five Pounds of Air Pressure, He Says

By Earl Sparling

Nikola Tesla is 79 years old, and he is one of the true geniuses of this time. Nevertheless, twenty-odd newspapermen came away from his Hotel New Yorker birthday party yesterday, which lasted six hours, feeling hesitantly that something was wrong either with the old man’s mind or else with their own, for Dr. Tesla, serene in an old-fashioned Prince Albert and courtly in a way that seems to have gone out of this world, announced that: –

1. He had discovered the so-called cosmic ray in 1896, at least five years before any other scientist took it up and twenty years before it became popular among scientists, and he is now convinced that many of the cosmic particles travel fifty times faster than light, some of them 500 times faster.

Needs No Commutator

2. He has found a way to produce a direct electric current by induction and without the use of a commutator, which is something the experts in electricity have considered impossible for the past hundred years.

3. He has invented an “absolutely impossible” machine which will impart vibrations to the earth which, with proper receiving apparatus can be picked up anywhere on the earth’s surface, and that this mysterious machine will allow scientists to explore the deep interior of the earth, will enable practical geologists to discover gold, coal and petroleum, and at the same time will give ships the means of navigating without compass or sextant.

Dr. Tesla has 600 to 700 patents to his name. He invented the rotary field motor, and is admittedly the seer and father of all modern electrical development. As has been his custom for five years now, he arranged his own birthday party, drank only hot milk as his part of the celebration, and made his announcements with the superb certainty of a man who knew what he was talking about, even if none of his guests did.

Tells of “Quake”

He said, among other things, that he expects to have $100,000,000 within two years, and he revealed that an earthquake which drew police and ambulances to the region of his laboratory at 48 E. Houston St. in 1887 or 1888 was the result of a little machine he was experimenting with at that time which “you could put in your overcoat pocket.”

The bewildered newspapermen pounced upon this as at least one thing they could understand and “the father of modern electricity” told what had happened as follows:

“I was experimenting with vibrations. I had one of my machines going and I wanted to see if I could get it in tune with the vibration of the building. I put it up notch after notch. There was a peculiar cracking sound.

“I asked my assistants where did the sound come from. They did not know. I put the machine up a few more notches. There was a louder cracking sound. I knew I was approaching the vibration of the steel building. I pushed the machine a little higher.

“Suddenly all the heavy machinery in the place was flying around. I grabbed a hammer and broke the machine. The building would have been down about our ears in another few minutes. Outside in the street there was pandemonium. The police and ambulances arrived. I told my assistants to say nothing. We told the police it must have been an earthquake. That’s all they ever knew about it.”

Watch Out, Mr. Smith

Some shrewd reporter asked Dr. Tesla at this point what he would need to destroy the Empire State Building and the doctor replied: – “Five pounds of air pressure. If I attached the proper oscillating machine on a girder that is all the force I would need, five pounds. Vibration will do anything. It would only be necessary to step up the vibrations of the machine to fit the natural vibration of the building and the building would come crashing down. That’s why soldiers always break step crossing a bridge.”

His early experiments in vibration, he explained, led to his invention of his “Earth vibrating machine. Tall and thin and ascetic face, his eyes sunken but …. humorous under protruding brows, he was cagey about describing what his new machine is, although he believes it will be “the chief thing of my many inventions posterity will thank me for.”

New York American
July 11, 1935


Power Through Earth A Startling Discovery

Nikola Tesla, father of radio and of the modern method of electric power transmission, observed his 79th birthday yesterday by drinking a quart of boiled milk and outlining the latest of his many startling discoveries.

While reporters ate turkey at a birthday luncheon given in his honor at the Hotel New Yorker Tesla described what he called his “greatest achievement in the field of engineering.”

This is an apparatus by which energy can be transmitted through the ground to any part of the earth, with practical possibilities in the navigation of ships, discovery of ore deposits and determination of the physical properties of the earth’s interior.

Cosmic Ray Studies

He announced also the successful passage of an induction current with a varying flux through a circuit without the use of a commutator – a feat believed impossible since the days of Faraday. And he revealed studies of the cosmic ray which, he said, exposed many of the major tenets of the theory of relativity as fallacious.

The eminent Jugoslavian physicist, who was laughed at when he announced. ’90’s, talked to the reporters for more than three hours.

His experiments in transmitting mechanical vibrations through the earth -called by him the art of telegeodynamics – were roughly described by the scientist as a sort of “controlled earthquake.”

The rhythmical vibrations pass through the earth with almost no loss of energy, he said, and predicted the system in time will be universally adopted, since it furnishes an “unfailing means of communication.. He asserted:

“It becomes possible to convey mechanical effects to the greatest terrestrial distances and produce all kinds of unique effects of inestimable value to science, industry and the arts.”

The invention could be used with destructive effect in war, he said, by exploding bombs thousands of miles away which had been equipped with apparatus to receive the vibrations.

“Incredible as it seems, I am able not only to produce current of one direction in a circuit by induction without a commutator, but also I can make this current almost as steady and continuous as that from a battery. I can obtain any tension I desire within reasonable limits by merely employing a greater number of turns in the circuit.”

He expressed the hope the invention could be applied as electric drive in automobiles and trucks.

Dr. Tesla dealt harshly with the relativity theory, calling it “A mass of error and deceptive ideas wrapped in a magnificent mathematical cloak.- He declared:

“Its exponents are very brilliant metaphysicists rather than exponents of positive science. Not a single one of the propositions of relativity have been proved..

New York Times
July 11, 1935, p. 23, c. 8


Scientist on Birthday Reveals Scheme to Send Mechanical Energy All Over World Would Even Guide Ships Assails Theory of Relativity as Work of Metaphysicians and not Scientific

Nikola Tesla, the man with seven hundred basic patents to his credit, who startled the world on a number of occasions in the past by achieving what others had regarded as impossible, including the large-scale generation and distribution of alternating current, yesterday treated the combined metropolitan press to a personally conducted tour of the labyrinthine laboratory of his fertile mind.

It was his seventy-ninth birthday anniversary, and, in keeping with his custom of past years, he made the day an occasion for revealing some of the latest products of his brain in the line of discovery, a field in which he rivaled and sometimes surpassed Edison during the golden era of electrical invention.

He confined himself yesterday to three of his startling adventures in the realm of theoretical and practical science. One of these, he said, “would appear almost preposterous.. The second, he said with true candor, “would be considered absolutely impossible by any competent electrical engineer.” The third would knock the props out from under the theory of relativity, he said, but in this case also he expressed his doubt that the modern generation of scientists would take his challenge seriously.

Cites Cosmic Ray Proof

He described relativity as “a beggar wrapped in purple whom ignorant people take for a king.”

In support of his statement he cited a number of experiments he had conducted, he said, as far back as 1896 on the cosmic ray. He has measured cosmic ray velocities from Antarus, he said, which he found to be fifty times greater than the speed of light, thus demolishing, he contended, one of the basic pillars of the structure of relativity, according to which there can be no speed greater than that of light.

Mr. Tesla treated the press, reporters, camera men, news and sound reel representatives, about 30 in number, to a gourmet’s luncheon in a private dining room at the Hotel New Yorker, where he has been making his home during the past two years. Mr. Tesla sat at the head of the table and talked while the reporters and camera men feasted on his bounty. He disdained each and every dish that was brought to him, not even touching his glass of water.

Toward the end of the luncheon he absented himself for a while and came back with a bottle containing a small quantity of pasteurized milk. This he poured in a silver chafing dish and heated to the proper temperature. Then came the surprise of the day – a birthday cake with a lone candle, a token of esteem by the management of the New Yorker to its distinguished bachelor guest.

His Greatest Achievement

One of the subjects, which he hoped, he said, will come to be recognized as his “greatest achievement in the field of engineering,” was, he said, the perfection by him of “an apparatus by which mechanical energy can be transmitted to any part of the terrestrial globe.”

This apparatus, he said, will have at least four practical possibilities. It will give the world a new means of unfailing communication; it will provide a new and by far the safest means for guiding ships at sea and into port; it will furnish a certain divining rod for locating ore deposits of any kind under the surface of the earth; and finally, it will furnish scientists with a means for laying bare the physical conditions of the earth, and will enable them to determine all of the earth’s physical constants.

He called this discovery “tele-geodynamics,” motion of earth-forces at a distance. It is of this, he said, that it would “appear almost preposterous.” m e apparatus, he added, is “ideally simple,” consisting of a stationary part and a cylinder of fine steel “floating” in air. He has found means, he said, of impressing upon the floating part powerful impulses which react on the stationary part, and through the latter to transmit energy through the earth.” To do this he has “found a new amplifier for a known type of energy, and the “purpose is to produce impulses through the earth and then pick them up whenever needed.”

The second invention, which, he said, “will be considered absolutely impossible by any competent electrical engineer,” was described by him as a new method and apparatus for producing direct current without a commutator, “something that has been considered impossible since the days of Faraday.” “Incredible as it seems,” he said, “I have found a solution for this old problem.”

Cosmic rays, he asserted, he found are produced by the force of “electrostatic repulsion.; they consist of powerfully charged positive particles which come to us from the sun and other suns in the universe. He determined, “after experimentation,. he added, that the sun is charged “with an electric potential of approximately 215,000,000,000 volts, while the electric charge stored in the sun amounted to approximately 50,000,000,000,000,000,000 electrostatic units.”

The theory of relativity he described as “a mass of error and deceptive ideas violently opposed to the teachings of great men of science of the past and even to common sense.”

“The theory, “he said, “wraps all these errors and fallacies and clothes them in magnificent mathematical garb which fascinates, dazzles and makes people blind to the underlying errors. The theory is like a beggar clothed in purple whom ignorant people take for a king. Its exponents are very brilliant men, but they are metaphysicists rather than scientists. Not a single one of the relativity propositions has been proved.”

New York Herald Tribune
August 18, 1935


By Nikola Tesla

Condensation of the primary substance is going on continuously, this being in a measure proved, for I have established by experiments which admit of no doubt that the sun and other celestial bodies steadily increase in mass and energy and ultimately must explode, reverting to the primary substance.

Activating Rays Linked to Sun

When radio-active phenomena were discovered I was prepared to view them merely as secondary effects of an external radiation, and as no trace of such a disturbance could be detected on earth I concluded that the primary activating rays were of cosmic origin and most likely to emirate from suns closely resembling our luminary. As the first step toward clearing up the mystery I undertook to ascertain whether the sun was charged to a potential sufficiently high to produce the tremendous electro-static repulsion which I had found to be the only force in nature capable of accounting for the phenomena.

The subject required extended investigation, but I finally ascertained with a reasonable degree of certitude, and to my amazement, that the sun was at a constant positive potential of about 216,000,000,000 volts. Thus the secret of the cosmic rays was revealed. Owing to its immense charge, the sun imparts to minute positively electrified particles prodigious velocities which are governed only by the ratio between the quantity of free electricity carried by the particles and their mass, some attaining a speed exceeding fifty times that of light.

“Erroneous Views” Sighted

The literature of cosmic rays is remarkable for its extent and almost as much for the erroneous views propounded. In this brief communication I can dwell on only a few of these.

It is held, in accordance with findings, that at great altitude the intensity of the rays is more than 10,000 per cent greater than at sea level. I have pointed out that the maximum possible increase could hardly exceed 50 per cent, and is, in reality, much smaller. How, then, can the phenomenal intensities recorded be explained? The answer is simple. The effects are due to radiations entirely different from the cosmic, longitudinal pulses in the ether, which behave like particles of relatively small penetrative but extraordinarily great ionizing power.

Then, again, it is said that the rays are much weaker at the equator, or near it, than in greater latitudes or at the poles. But this is only true for a limited height, beyond which the intensity is the same all over the earth. I found the discrepancy to be due to a partial neutralization of the positive particles composing the rays by the negative carried by rising air currents. In the equatorial zones this neutralizing action may be so great as to reduce the intensity of the rays to a few per cent of the normal. In the moderate zones and polar regions the positively charged descending air produces the opposite effect, thus increasing the difference in the intensities recorded in different latitudes.

Energy Appraisal Called Faulty

The greatest mistake is made in the appraisal of the energy of cosmic rays. In most cases the ionizing action is used as a criterion, which is useless, for the most powerful cosmic rays virtually do not ionize at all and leave no trace of their passage through the instrument. I have resorted to different means and methods and have found that the energy of the cosmic radiations impinging upon the earth from all sides is stupendous, such that if all of it were converted into heat the globe quickly would be melted and volatilized.

Since expressing, in 1896, my ideas on the origin and character of cosmic rays and of the cause of radioactivity, all my views have been confirmed by my own findings and those of others, while the numerous theories advanced have been proved false or inadequate. Those who are still doubting that our sun emits powerful cosmic rays evidently overlook that the solar disk, in whatever position it may be in the heavens, cuts off the radiations from beyond, replacing them by its own.

As the radiations from the sun are only a little more intense than those coming from other directions, the lack of pronounced differentiation has deceived the observers. Regarding radio-activity, it occurs exactly as required by my theory. The radio-active emanations from the globe are secondary effects of external rays and two-fold – one part coming from the energy stored, the other from that continuously supplied.

New York Times
July 11, 1936, II p. 1, c. 2


Says His Wireless Invention Will Gird the Earth With Energy for Industry

Nikola Tesla, inventor, who celebrated his eightieth birthday yesterday foresaw an industrial civilization founded on cheap and unlimited power transmitted from a central point to any part of the globe without wires.

This new system of power transmission will have its first practical demonstration within a year, Dr. Tesla predicted. He said he had perfected the principles which will create the necessary apparatus.

Each year on his birthday the inventor of the principle of the rotary magnetic field, new forms of dynamos, transformers and 700 other devices which have played leading roles in technological development plays host to the press. Yesterday he gave a luncheon for fifteen newspaper men and women at the Hotel New Yorker, and while his guests feasted he contented himself with three oranges and a quart of milk.

Recalls Interesting Episodes

Dr. Tesla recalled his first meeting with Thomas A. Edison, relived some of the interesting episodes in his own life, describing his researches into such varied fields as relativity, death rays, psychic phenomena, lightning machines and power development.

Between sips of the warm milk, he eyed the newspaper folk with their Scotch and sodas and confided that if he had not given up drinking alcohol with the enactment of prohibition he would live to be 150 years old.

“As it is, I believe my abstinence from alcohol during the latter part of my life has lopped off fifteen years from my life, and now I expect to live only 135 years.. he remarked, “Alcohol is the elixir of life, but when this country passed the Prohibition Law I felt that as a patriotic American I should stop drinking whisky. I have not touched it Since.”

Meat is another food which he never touches, Dr. Tesla explained. Two quarts of milk a day provide him with all the proteins and calories he needs to remain alive, he said. Although as a rule he does not retire until 5:30 o’clock every morning, he gets up about 10 A. M. and feels full of energy.

The development of wireless transmission of power will overshadow any of his past accomplishments and will usher in a new civilization for mankind, Dr. Tesla predicted. He explained that his system will make it possible, for example, to install a hydro-electric plant at Muscle Shoals and transmit the power generated to England, China, Little America or Alaska with equal ease and at comparatively little cost.

New York Times
July 11, 1937, p. 13, c. 2


Inventor, 81, Talks of Key to Interstellar Transmission and Tube to Produce Radium Copiously and Cheaply – Decorated by Yugoslavia and Czechoslovakia

Reports of discoveries by which it will be possible to communicate with the planets and to produce radium in unlimited quantity for $1 a pound were announced by Dr. Nikola Tesla yesterday at a luncheon on his eighty-first birthday at which he wee honored with high orders from the Yugoslav and Czechoslovak Governments.

Dr. Tesla, whose discoveries in electrical science have won for him recognition as the father of modern methods of generating and distributing electrical energy, asserted his “absolute” belief that he would win the Pierre Guzman prize of the Institute of France for his discovery relating to the interstellar transmission of energy.

Following his annual custom, Dr. Tesla played host to a group of newspaper men at his birthday luncheon at the Hotel New Yorker and issued the announcement of his discoveries of the last year. No apparatus or sketches were shown, but Dr. Tesla said in announcing perfection of the principle of a new tube, which he said would make it possible to smash the atom and produce cheap radium, that he would be able to give a demonstration in “only a little time.”

Guests at Dr. Tesla’s luncheon included Constantin Fotitch, Minister from Yugoslavia Vladimir Hurban, Minister from Czechoslovakia; R. Petrovich, first secretary of the Yugoslav delevation; B. P. Stoyanovitch, Yugoslav Consul General in New York; Dr. J. Nemeck, Counselor of the Czechoslav Legation, and J. Hajny, Acting Consul General in New York for Czechoslovakia.

Presenting to Dr. Tesla the Grand Cordon of the White Eagle, highest order of Yugoslavia, Mr. Fotitch announced it was the first time the order had been granted to an American for civil accomplishments. The honor was bestowed by order of Ring Peter through the Regent, Prince Paul.

Dr. Tesla’s career has been an inspiration to the youth of his native country, the Minister said. Evidently referring to Dr. Tesla’s report several years ago of inventing a “death beam” for use as a defense weapon, the Minister said:

“All your efforts are directed to find a way, by means of some new magic invention of yours, by which you will check and render futile as much as possible all those inventions which men have invented to destroy mutually one another. You feel, as we all feel in your old country, that the world has seen enough of horror and that after so many examples of heroism displayed in the Great War, humanity has found a better way only in peace.”

Mr. Hurban, presenting the Grand Gordon of the White Lion, which has been granted to such other distinguished Americans as Secretary Kellogg, Elihu Root and Dr. Nicholas Murray Butler, said “our Czechoslovak nation’s brotherly feeling toward you as a son of Yugoslavia made it a duty, not a privilege, to give you this decoration in the name of the President of our nation. Dr. Edward Benes.” He also presented a diploma certifying Dr. Tesla’s honorary degree as a doctor of the University of Prague.

Outlines His Discoveries

Dr. Tesla, in responding, said he considered Czechoslovakia “one of the most enlightened countries in the world.”

In a ten-page typewritten statement outlining his discoveries, Dr. Tesla gave a resume of his work in the fields of gravity and cosmic rays. Asserting that “the so-called cosmic rays observed at great altitudes presented a riddle for more than twenty-six years chiefly because it was found that they increased with altitude at a rapid rate,. Dr. Tesla said he had discovered “the astonishing fact that the effects at high altitudes are of an entirely different nature, having no relation whatever to cosmic rays..

He gave a detailed technical description of his conclusions from research and calculations concerning the cosmic ray, and continued:

“For the time being, I must content myself with the announcement of the salient facts, but in due course I expect to be able to give more or less accurate technical data relating to all particulars of this discovery.”

Digressing from his prepared statement, he said: “I -am proud of these discoveries, because many have denied that I am the original discoverer of the cosmic ray. I was fifteen years ahead of other fellows who were asleep. Now no one can take away from me the credit of being the first discoverer of the cosmic ray on earth..

Dr. Tesla’s audience stirred as he took up the next phase of his discoveries.

“I have devoted much of my time during the year past,” he said, “to the perfecting of a new small and compact apparatus by which energy in considerable amounts can now be flashed through interstellar space to any distance without the slightest dispersion.”

To Claim French Award

Explaining that he did not refer to his “universal peace discovery. Dr. Tesla continued.

“I am expecting to put before the Institute of France an accurate description of the devices with data and calculations and claim the Pierre Guzman prize of 100,000 francs for means of communication with other worlds, feeling perfectly sure that it will be awarded to me. The money, of course, is a trifling consideration, but for the great historical honor of being the first to achieve this miracle I would be almost willing to give my life.

“I am just as sure that prize will be awarded to me as if I already had it in my pocket. They have got to do it. It means it will be possible to convey several thousand units of horsepower to other planets, regardless of the distance. This discovery of mine will be remembered when everything else I have done, is covered with dust.”

Reporters questioned Dr. Tesla closely on his report of an interplanetary communication system. He said he had been working in several laboratories, but refused to disclose where they were. Asked if he had a working model of the apparatus, he said, “It employs more than three dozen of my inventions, it is a complex apparatus, an agglomeration of parts.”

“It is absolutely developed,” he declared. “I wouldn’t be any surer that I can transmit energy 100 miles that I am of the fact that I can transmit energy 1,000,000 miles up.”

A different kind of energy than is commonly employed must be used, however, he said, explaining further that “you must realize it travels through a channel of less than one-half of one-millionth of a centimeter.”

“I could undertake a contract to manufacture the apparatus,” he asserted.

Dr. Tesla declared that “life on other planets is an infinite probability, a certitude.. A difficulty in using his apparatus, he said, would lie in hitting other moving planets with “The needlepoint of tremendous energy,. but astronomers could help solve this problem.

The point of energy could be aimed at the moon and “We very easily could see the effects, see the splash and the volatilization of matter.” He also pictured the possibility of advanced thinkers living on other planets and also experimenting in this field, but mistaking the Tesla energy rays for some form of cosmic rays.

Dr. Tesla provoked a new stir with his next announcement.

“My most important invention from a practical point of view,” he said, is a new form of tube with apparatus for its operation.”

Reports Tube of New Type

Recalling experiments with other tubes, he said he had been “rewarded with complete success’ and had “produced a tube which it will be hard to improve further..

“It is of ideal simplicity,” he said, “not subject to wear and can be operated at any potential, however high – even 100,000,000 volts – that can be produced. It will carry heavy currents, transform any amount of energy within practical limits and it permits easy control and regulation of the same.

“I expect that this invention, when it becomes known, will be universally adopted in preference to other form of tubes and that it will be the means of obtaining results undreamed of before.

“Among others, it will enable the production of cheap radium substitutes in any desired quantity and will be, in general, immediately more effective in the smashing of atoms and the transmutation of matter. However, this tube will not open up a way to utilize atomic or subatomic energy for power purposes.”

“It will cheapen radium so,” Dr. Tesla added, “that it will be just a cheap – well, it will get down to $1 a pound, in any quantity.”

Expressing ”annoyance” that some newspapers had indicated he would “give a full description” of his atom-smashing tube at yesterday’s luncheon, Dr. Tesla said he was bound by financial obligations “involving vast sums of money” against releasing this information.

“But it is not an experiment,” he declared. “I have built, demonstrated and used it. Only a little time will pass before I can give it to the world.”

A final discovery announced by Dr. Tesla involved a new method and apparatus for further perfection of vacuum tubes.

“What may be accomplished by means of such vacua is a matter of conjecture, but it is obvious that they will make possible the production of much more intense effects in electron tubes.” he said.

Before and during the luncheon, Dr. Tesla entertained his guests with colorful personal reminiscences and observations including his opinions on dieting and immortality.

New York Sun
July 12, 1937


Scientist, 81 Years Old, Celebrates Birthday

Decorated by 2 Countries

Seeks Guzman Prize for Idea on Plan Communication

Nikola Tesla is 81 years old. Some reference books, including “Who’s Who” fix the year of his birth at 1867. He does not know whether the anniversary should have been celebrated Friday or, as it was, on Saturday, because it was just at midnight between July 9 and July 10 that he was born. But the year was 1856.

It was a most unusual birthday party the inventor held at the Hotel New Yorker, where he makes his residence. For the Ministers of his native Jugoslavia and neighboring Czechoslovakia and their staffs, and a handful of newspaper men, Dr. Tesla had provided a most unusual material and mental feast.

Figuratively, at least, they are still smacking their lips today over the food and wines and speculating about what may come from the discoveries the scientist announced, his quest for the French Academy prize for interplanetary communication, the perfection of a tube to carry immense electrical voltages, and some of the more abstract observations regarding cosmic rays and what makes this universe of ours expand and contract, oscillating instead of always expanding as some physicists hold.

Considering his years and the fact that recently he was the victim of an automobile accident which shook his system seriously, Dr. Tesla is exceedingly vigorous. His thinning hair, although predominantly white, still has considerable black. His eyes are as keen and penetrating as ever. He speaks distinctly although, of course, with a bit of the accent he has always had. But he picked up questions quickly and answered them in a manner that showed a tremendous grasp of all the latest theories of the astronomers, physicists and other scientists.

Announces Discoveries

In recent years Dr. Tesla has made a habit of announcing on his birthdays some of the discoveries he has made in the past year; and he feels that with the passing of the years they have increased in importance. He said: “The maximum power of man is reached in his age rather than in his prime, as many suppose. Every one should have a decade to sum up the work of his lifetimes after he reaches the age of seventy-five. By then, if he has worked constantly in one field, he has gained so much experience that the solution of problems becomes much easier.”

Everything at the birthday party was designed to lead up to the discussion of the inventor’s latest achievements. Although he tasted only two of the courses and refrained altogether from any drink but water, he treated his guests to the finest in foods and wines.

The piece de resistance was “Canard en casserole a la Tesla” a dish he had planned himself about ten years ago, consisting of duck roasted slowly in a casserole, smothered with whole stalks of celery. It won unstinted praise from the diplomatic representatives.

Dr. Tesla did take just a taste of this dish to make certain that it had been properly prepared and, as a sign of his approval had the chef come in to receive the applause of his guests. The other dish of which he partook was a jellied consomme.

Alcohol, he believes, is a great thing. Whisky and wine are preferable to coffee and tea. As his guests smacked their lips over some of the vintages he had brought forth for the occasion, they were disposed to agree with Dr. Tesla on this point.

Genius From Parents

It was in the random conversation of the meal that one learned many intimate things about Dr. Tesla. He gave little glimpses of his boyhood life in Jugoslavia. One gathered he had acquired much of his genius from his learned father, a Slavian priest, and his mother, a practical and also a brilliant woman.

When, in 1884, Dr. Tesla landed at the Battery he had just 4 cents. He had only gone a few blocks up Broadway when he saw some men sweating over an electrical machine that had broken down.

“It was a machine I had helped to design, but I did not tell them that. I asked, ‘What is the matter?’ and they said, ‘This thing won’t work.’ I asked, ‘what would you give me if I fix it?’ ‘Twenty dollars’ was the reply. I took off my coat and went to work. I had it running perfectly in an hour and had earned $20.”

He shortly found it was not all so easy as that. There were many days when he did not know where the next meal was coming from. “But I was never afraid to work. I went to where some men were digging a ditch. I said I wanted to work. The boss looked at my good clothes and white hands and he laughed to the others. ‘This man wants to work.’ But he said ‘All right. Spit on your hands. Get in the ditch. Go to work.’ And I worked harder than anybody. At the end of that day I had $2. And I kept it up until I had enough to get started again.”

Support Bums Today

“Could that happen today?” he was asked. There was a serious pause, a grave frown and he said, “I am afraid not. The present is destructive. The workers are expected to support the bums.”

Before the birthday cake was cut Dr. Tesla was invested with the orders which Jugoslavian and Czechoslovakian ministers had brought. Dr. Constantine Fotitch, Jugoslavian Minister, who was attended by R. Petrovich, first secretary of his legation, and B. F. Stoyanovich, the Consul-General here, bestowed the grand Cordon of the White Eagle in behalf of King Peter.

Dr. Tesla sharply assailed those physicists who contend that cosmic rays originate in far places of the universe where matter is converted into energy. He produced a formula saying “The kinetic and potential energy of a body is the result of motion and determined by the product of its mass and the square of its velocity. Let the mass be reduced, the energy is diminished by the same properties. If it be reduced to zero, the energy is likewise zero for any finite velocity.”

About half of his talk was devoted to abstract scientific problems.

Turning from the more metaphysical aspects of his studies to the practical, Dr. Tesla disclosed his greatest ambition is to be the man who evolved a method of communicating with other planets. He thinks he has found the answer and is preparing to lay its formula before the Institute of France in quest of the Pierre Guzman price of 100,000 francs offered for a means of communicating with other worlds.

The man who accomplishes this, he feels, will be remembered after all present inventions are forgotten.

New York Herald Tribune Aug. 22, 1937


Inventor Hopes to Use Energy-Transmitting Device to Make Spot Glow on Lunar Surface

Theory Is Traced To ’97 Experiments

His Mechanism to Use Vast Natural Forces, Possibly Cosmic Rays

By John J. O’Neill

The failure of forecasters to predict the results of scientific discoveries, particularly with respect to their social and economic significance, was emphasized in the recent report on technical trends and their social implications submitted to President Roosevelt by the National Resources Committee. One of the outstanding oversights was radio broadcasting. None of the previewers of coming events saw this development of radio communication.

With this as justification, some attention might be given to the recent announcement by Nikola Tesla, the inventor, whose mind has given us a great many of the major developments forming the foundation of our electrical age. Dr. Tesla seldom writes for publication, but back in 1900 he wrote an article for the June issue of “The Century Magazine,” which contained predictions that seemed at that time very fantastic. Those who may read it now will be amazed to find how many of the author’s prophecies have proved true.

Advance Seen Fantastic

Some of the advances described by him during the last few years as the result of his investigations may appear equally fantastic today, but one has only to know of Dr. Tesla’s past performances in order to have faith that given time and money they could be made realities. Forty years ago he was playing with electrical discharges of many millions of volts, while today scientists have difficulty in developing a fraction of those potentials for their atom-smashing and x-ray experiments. Long before the days of Marconi, Tesla girdled the earth with giant electrical waves from his high voltage generators, and on the basis of this work predicted both the “transmission of intelligence without wires” and the “wireless transmission of power.. He controlled a vessel at a distance by wireless power forty years before the advent of our present-day manless aerial torpedoes.

“They laughed at me in 1897 when I told them about the cosmic ray,. he said in a recent interview. “Fifty years ago they attempted to discredit my discovery of the rotating magnetic field and my system of power transmission by alternating currents. They called me crazy when I predicted the radio and when I sent the first impulse around the world they said it couldn’t be done..

So with Tesla’s latest discoveries and inventions. There may be many who are skeptical, but the world is moving forward rapidly and man is constantly doing things a short time before considered impossible. Forty years ago Tesla was predicting world-wide radio communications. Today this accomplishment is history. Now he is predicting interplanetary communication.

Jovian Bolts His Aim

Dr. Tesla gave assurance that he did not mean just sending weak signals, but veritable Jovian bolts carrying energy of several thousand horsepower which would be able to produce tremendous effects at the receiving end, even though it be infinitely remote. A test of this invention could be made most advantageously on our nearest heavenly neighbor, the moon. Sufficient energy, he said, could be transmitted to render a small spot on its surface incandescent so that it could be easily observed from the earth.

This is a further extension of the announcement previously made by Dr. Tesla that he would be able to transmit over a beam of not more than one hundred thousandths of a square centimeter in cross section adequate amounts of energy for operating all kinds of machinery at distances limited only by the earth’s curvature. Such a beam, he pointed out, could be used not only for constructive but also destructive purposes as annihilating military forces or aerial fleets.

While Dr. Tesla is keeping a deep secret of the mechanism by which he plans to provide unlimited energy, it is apparent he is bent on using natural forces that operate on a vast scale. To be specific, it seems that the energy is coming to us in the form of cosmic rays, but Tesla’s theory of these rays is different from those of Dr. Robert A. Millikan or Dr. Karl T. Compton.

He formulated his theory in 1897 when he sought to explain the production of the phenomena of radio activity by some other means than atomic explosions. He held that all energy an atom exhibits is received from its environment and does not come from itself. Accordingly, he explained radio activity as a result of the shattering of atoms by sub-atomic cosmic particles. Whence did they come? was the question.

“Now, of all bodies in the cosmos,” states Dr. Tesla, “our sun was the most likely to furnish a clue as to their origin and character. Before the electron theory was advanced, I had established that radio-active rays consisted of particles of primary matter not further decomposable, and the first thing to find out was whether the sun is charged to a sufficiently high potential to produce the effects noted. This called for a prolonged investigation which culminated in my discovery that the sun’s potential was 216,000,000,000 volts and that all such large and hot bodies emit cosmic rays.

Puzzle of Mystery Rays

“While the origin and character of the rays observed near the earth’s surface had thus been sufficiently well ascertained, the so-called cosmic rays observed at great altitudes presented a riddle for more than twenty-six years, chiefly because it was found they increased with the height at a rapid rate. My investigations brought out the astonishing fact that the effects at high altitude are of an entirely different nature, having no relation whatever to cosmic rays. These are particle. from celestial bodies at very high temperatures and charged to enormous electrical potentials.”

It might be remarked parenthetically that Dr. Tesla does not accept the concept of the electron presented by physicists as an elementary unit and carrying a unit charge of electricity. He holds that the electron in a well-exhausted tube operated at high potential carries many multiples of this unit charge. The ignorance of this fact is responsible for many errors and fallacies in various scientific investigations.

“The effects at great elevations,” Dr. Tesla continued, “are due to waves of extremely small lengths produced by the sun in a certain region of the atmosphere. This is the discovery I wish to make known. The process involved in the generation of the waves is the following: The sun projects charged particles constituting an electric current which passes through a conducting stratum of the atmosphere approximately ten kilometers (six miles) thick enveloping the earth. This is a transmission of electrical energy exactly as I illustrated in my experimental lecture in which one end of a wire is connected to an electric generator of high potential, its other end being free. In this case the generator is represented by the sun and the wire by the conducting air.

Production of the Waves

“The passage of solar current involves the transference of electric charges from particle to particle with the speed of light, resulting in the production of extremely short and penetrating waves. As the air stratum mentioned is the source of the waves it follows that the so-called cosmic rays observed at great altitude must increase as this stratum is approached.”

Another of the Tesla inventions is a radically new tube which is indestructible and can handle heavy currents up to any voltage that can be produced, even 100,000,000 volts. It will be useful, he promises, in the production of cheap radium substitutes and in the transformation of matter. Still another invention consists in means for the production of a practically perfect vacuum of the order of 1,000,000,000th of a micron.

While Dr. Tesla does not say so, it is assumed that these latter inventions are parts of the system which he would use in the transmission of energy to the moon or other planets. Such an application would be spectacular, but the inventions when described and made public would have applications of more immediate practical value in industrial operations.

He was honored on his birthday by the bestowal of the highest distinctions within the power of Yugoslavia and Czechoslovakia, which recognition touched him deeply, all the more as Konstantin Fotitch and Vladimir Hurban, ministers of these countries, came from Washington especially for the occasion. Dr. Tesla is now eighty-one and works continuously at his investigations. He has not been halted even by a recent accident in which he was knocked down by a taxicab. It merely caused the customary bruises and upset the digestion a bit, he said.

Baltimore Sun
July 12, 1940


Noted Inventor Says His Ray Will Melt Plane Motors at 250 Mile Range

New York, July 11 – Nikola Tesla, one of the greatest electrical inventors of the century, who reached 84 yesterday, said today he was ready to divulge to the United States Government the secret of a “death beam” that would melt airplane motors at a distance of 250 miles and thus would build an invisible wall of defense around the country against attempted attack by an air force, no matter how large.

Dr. Tesla first described his “death beam. six years ago on the day he reached 78.

Dr. Tesla, who spent this birthday at work on his inventions, offered his services to the Government in reply to a question over the telephone whether his death beam had reached the stage of practical application.

At Service of U. S.

“All my inventions,. he said, “are at the service of the United States Government..

The death beam, he said, is “based on an entirely new principle of physics that no one has ever dreamed about.” The principle, he added, was different from those relating to the transmission of electrical power by wireless, as announced by him several years ago.

The beam, he said, would be only one hundred-millionth of a square centimeter in diameter and could be generated from a special plant that would cost no more than $2,000,000 and would take only about three months to construct. A dozen such plants, located at strategic positions along the coast, he said, would be enough to defend the country against all possible aerial attack.

Would Melt Any Engine

The beam would melt any engine, whether Diesel or gasoline driven, and would also ignite any explosives aboard. No possible defense against it could be devised, as it would be all-penetrating, he declared.

Should the Government decide to take up his offer, he said, he would go to work at once and keep on working “until I collapse.” However, he added, “I would have to insist on one condition – I would not suffer interference from any experts. They would have to trust me.” He was in good health, he said, and felt confident he could undertake the task.

The beam, he said, involved four new inventions:

A method and apparatus for producing rays and other manifestations of energy in free air, eliminating the necessity for high vacuums.

A method and process for producing “very great electrical force.

A method for amplifying this force.

A new method for producing “a tremendous electrical repelling force.

Voltage 50,000,000

This would be the projector, or gun, of the system. The voltages for propelling the death beam to its objective, he stated, will attain a potential of 50,000,000 volts.

With this enormous voltage, he said, microscopic electrified particles of matter will be catapulted on their mission of defensive destruction.

Dr. Tesla added he was convinced that “the battleship is doomed” and that “What happens to the armored knight will also happen to the armored vessel.” The Germans, he said, are not planning to invade England, but will attack its fleet.

For this reason, he said, he was convinced that money spent on battleships would be wasted. The money planned for battleships, he said, should be “directed in channels that will improve the welfare of the country.”

New York Times
Sept. 22, 1940, Sec. 2, p. 7


Nikola Tesla, one of the truly great inventors who celebrated his eighty-fourth birthday on July 10, tells the writer that he stands ready to divulge to the United States Government the secret of his “teleforce,” with which, he said, airplane motors would be melted at a distance of 250 miles, so that an invisible Chinese Wall of Defense would be built around the country against any attempted attack by an enemy air force, no matter how large.

This “teleforce,” he said is based on an entirely new principle of physics that “no one has ever dreamed about,” different from the principle embodied in his inventions relating to the transmission of electrical power from a distance, for which he has received a number of basic patents. This new type of force, Mr. Tesla said, would operate through a beam one one-hundred-millionth of a square centimeter in diameter, and could be generated from a special plant that would cost no more than $2,000,000 and would take only about three months to construct.

A dozen such plants, located at strategic points along the coast, according to Mr. Tesla, would be enough to defend the country against all possible aerial attack. The beam would melt any engine, whether Diesel or gasoline driven, and would also ignite the explosives aboard any bomber. No possible defense against it could be devised, he asserts, as the beam would be all-penetrating.

High Vacuum Eliminated

The beam, he states, involves four new inventions, two of which already have been tested. One of these is a method and apparatus for producing rays “and other manifestations of energy. in free air, eliminating the necessity for a high vacuum; a second is a method and process for producing “very great electrical forcer; the third is a method for amplifying this force, and the fourth is a new method for producing “A tremendous electrical repelling force”. This would be the projector, or gun, of the system. The voltage for propelling the beam to its objective, according to the inventor, will attain a potential of 50,000,000 volts.

With this enormous voltage, he said, microscopic electrical particles of matter will be catapulted on their mission of defensive destruction. He has been working on this invention, he added, for many years and has recently made a number of improvements in it.

Mr. Tesla makes one important stipulation. Should the government decide to take up his offer he would go to work at once, but they would have to trust him. He would suffer “no interference from experts.”

In ordinary times such a condition would very likely interpose an insuperable obstacle. But times being what they are, and with the nation getting ready to spend billions for national defense, at the same time taking in consideration the reputation of Mr. Tesla as an inventor who always was many years ahead of his time, the question arises whether it may not be advisable to take Mr. Tesla at his word and commission him to go ahead with the construction of his teleforce plant.

Such a Device “Invaluable”

After all, $2,000,000 would be relatively a very small sum compared with what is at stake. If Mr. Tesla really fulfills his promise the result achieved would be truly staggering. Not only would it save billions now planned for air defense, by making the country impregnable against any air attack, but it would also save many more billions in property that would otherwise be surely destroyed no matter how strong the defenses are as witness current events in England.

Take, for example, the Panama Canal. No matter how strong the defenses, a suicide squadron of dive bombers, according to some experts, might succeed in getting through and cause such damage that would make the Canal unusable, in which case our Navy might find itself bottled up.

Considering the probabilities in the case even if the chances were 100,000 to 1 against Mr. Tesla the odds would still be largely in favor of taking a chance on spending $2,000,000. In the opinion of the writer, who has known Mr. Tesla for many years and can testify that he still retains full intellectual vigor, the authorities in charge of building the national defense should at once look into the matter. The sum is insignificant compared with the magnitude of the stake.

Philadelphia Inquirer
October 20, 1940


“The beam would melt enemy airplane motors before they approached our coasts and blow up hostile bombers.”

The man was old, but the fervor in his eyes was ageless. Deep-set, they looked out beneath the bushes of his brows.

“If only they will let me try out my new teleforce’. exclaimed Nikola Tesla, who has been called one of the greatest electrical inventors since Benjamin Franklin flew his kite. “If only they will let me show how this Nation can be made invulnerable to air attack!.

Thus, just the other day, spoke the man who years ago helped to harness Niagara Falls, through his discovery of the principle of the rotary magnetic field. The man who is known as the father of modern methods of generating and distributing electrical energy. Who in 1904 predicted that the human voice one day would girdle the globe, and whose famed Tesla coil helped to make that prediction of radio come true.

Today, at 83, Nikola Tesla lives in a New York hotel and dreams of making America one vast, impregnable fortress. He says that he can do this.

Tesla is used to skeptics who, he says, laughed at him back in the old days when he worked at Orange, New Jersey, with Thomas A. Edison. Tesla helped Edison design motors and generators. Then of course there was a great deal of laughing in 1904 over Tesla’s idea that the human voice would one day wing around the world.

Today, trembling with excitement, this slim old man tells how his newest invention (he holds 700 patents) can melt airplane motors at a distance of 250 miles away from the American coastline, so that invading aviators would drop into the sea.

“My new teleforce,” he declares, “is based on an entirely new principle of physics that nobody ever has dreamed of. It is different from the principle embodied in my inventions relating to the transmission of electrical power from a distance, for which I hold a number of basic patents.”

For years Tesla worked on the problem of transmitting electrical power from a distance, without bringing this dream out of the laboratory into the workaday world. But he was not alone in his belief that it eventually will be done. The great Marconi, shortly before his death, predicted that the day would come when power would be directed through the air with little loss. And like Tesla, Marconi was reported to have been working on a war-ray. His, it was said, would when perfected be able to stop airplane and other motors many miles before invading forces could reach their goals.

For U. S. Alone

Marconi said little about his mysterious ray, nor will Tesla discuss the details of his. It is his secret and he will not reveal it, he says, except to the United States Government, for he is afraid that it might be stolen by enemies of America, within and without. But of what it will do, he speaks freely.

“This new type of force,” he said the other day, “would operate through a beam one one-hundred-millionth of a centimeter in diameter. It could be generated from a special plant that would cost no more than two million dollars and would take only about three months to construct.

“A dozen such plants, located at strategic points along the coast, would be enough to defend this country against all possible aerial attack. This beam would melt any engine, whether Diesel or gasoline-driven.” (Marconi’s partly-perfected beam was said to be ineffective against Diesel engines). “It would also ignite any explosives aboard any bomber. No possible defense against it could be devised, as the beam would be all-penetrating.”

Four recent inventions, Tesla says, are used in the generation of the ray. Two of them already have been tested, it is said. One of these is an apparatus for producing rays “and other manifestations of energy. in free air, instead of in a vacuum.

The second is a process for producing “A very great electrical force.. Next is a method for amplifying this force and finally there is a new method for producing “A tremendous electrical repelling force.. This, Tesla declares, would be the projector, or gun, of the teleforce system. It would operate on a potential of 50,000,000 volts.

Dramatically, Tesla describes how this titanic voltage would hurl into space billions of microscopic electrical particles of matter that would bring down invading airplanes as insects are dropped by a spray gun.

All this, Tesla says, he is offering to the United States, the land which welcomed him as an immigrant boy from Austria-Hungary in 1884. But there must be no “red tape,” if he is to go to work setting up the first power plant. There must be no “interference from experts.

Offers like this have been made before, and tests have proved many so-called “death rays” useless. But some authorities, remembering the great achievements of Nikola Tesla, believe his claims should be investigated. Why, they ask, should such a ray be considered impossible in a world where radio is a commonplace? They recall the case of Henry Fleur, who was prosecuted in San Francisco by disgruntled investors who claimed he had bamboozled them with a death-ray machine intended to kill insects.

In the courtroom, Fleur turned his machine on a couple of termites. They died in seconds. -A lizard and a snake also were killed by the ray, though it look longer. Fleur was released. He said that he never would experiment with his apparatus to make it a man-killer.

Inventor’s Offer

Then there is Dr. Antonio Longoria, who says that he destroyed a death ray machine which he invented in 1933, because it was too dangerous. Of this machine, Albert Burns, president of the Inventors’ Congress in 1934, said that he had seen it kill pigeons, rabbits, dogs and cats at considerable distances. Now Dr. Longoria said that he is willing to re-assemble his apparatus in the event that the United States is subjected to an unwarranted attack. He claims that it worked by changing the red corpuscles of its victims’ blood to white. And he says that it might be adapted to stall the motors of airplane engines in flight.

If such things are possible, some authorities ask: why not give Nikola Tesla the chance he asks to try out his defensive death ray? True, he has been called the greatest dreamer among the inventors who created the present electrical era. But many of his dreams came true. Perhaps, they say, this one might come true, too – and build a wall mightier than any in the world around America’s borders.

May 16, 1948, pp. 1147 – 1159

NIKOLA TESLA by Kenneth M. Swezey


In the early 1890s, Tesla discovered the “rotating magnetic field. produced by two or more alternating currents out of step with each other.

Based on this discovery, Tesla proceeded to invent the prototypes of almost all practical alternating current motors and the whole polyphase system for generating, transmitting, and distributing electric current as well.

The first Tesla polyphase system patents were granted on May 1, 1888. The Westinghouse Electric Company acquired rights to them several months later, and in 1893 was able to demonstrate a complete system at the Chicago World’s Fair. The demonstration was so convincing that – against the warnings of such men as Edison and Lord Kelvin – the Tesla system was adopted for the first great hydro-electric plant at Niagara Falls, which started operation in 1895. A year later, Niagara power was running street cars and lights in Buffalo. The age of Electric Power was thus born.

Today, practically all electricity in the world is generated, transmitted, and turned into mechanical power by means of the Tesla Polyphase System. Without this system, the giant steam-electric power plants in our big cities and the big hydroelectric protects such as TVA, Boulder Dam, Grand Coulee, would be impossible.

Although practically unknown to the layman, the Tesla polyphase inventions are, without question, the most important single group of inventions in the whole field of electrical engineering.


Dr. L. W. Austin, head of the radio section of the Bureau of Standards for many years, Prof, Slaby, German radio pioneer (the “Marconi of Germany”), M. E. Girardeau, French radio authority, and others, have called Tesla the “Father of the Wireless.” This was for his inventions and discoveries made at least several years before the very first experiments of Marconi and others. Here are several:

High frequency generators for producing continuous waves.

Coupled and tuned circuits.

Rotary and series spark gaps.

Oil-insulated transformers and condensers.

Mica condensers impregnated with wax under vacuum.

Stranded conductors.

Aerial and ground connection.

Selective tuning by beat waves or heterodyning.

Arcs for producing continuous waves.

“Ticker” for receiving continuous waves.

Choke coils.

Radio-Controlled Vessels.

Before 1897, Tesla devised boats, cars, and other movable objects that could be maneuvered completely by radio waves. He demonstrated these widely in New York in 1898, and before the Commercial Club in Chicago in 1899. This work with what Tesla called “Telautomatics,” advanced later by John Hays Hammond, Jr. and others, was the beginning of the concept which has led to today’s guided missiles.

High Frequency Induction Furnace and Heating

In the early 1890’s, Tesla described heating bars of iron and melting lead and tin in the field of specially designed high-frequency coils, also of heating dielectrics in such fields. When, in 1916, Dr. Edwin Northrup devised his first commercial high-frequency furnace, he told me he had gone back for his inspiration to the old ideas and circuits of Tesla.


During this same period, Tesla developed apparatus for producing high voltage, high frequency “Tesla currents.” He first reasoned, then demonstrated on himself that very high voltages could be taken safely into the human body provided the frequencies were high enough – thus making a discovery in physiology. Soon after, adapted by D’Arsonval and others, the Tesla apparatus became the basic tool of diathermy and other forms of high-frequency electro-therapeutics.

Neon and Fluorescent Lighting

Before 1893, Tesla devised all kinds of wirelessly-lit vacuum and gas-filled tubes. He increased the brilliance of some by using uranium glass or coating them with phosphors – thus creating pioneer fluorescent tubes. He bent many to suit the requirements of the room they were to light, and others to form words or names just as we do in modern display lighting. Tesla displayed some of his neon-type tubes in his personal exhibit at the 1893 World’s Fair.

Mechanical Power

Tesla devised a turbine having smooth parallel blades, without buckets. The principle, which involved the friction of air, steam, or gas, at high velocity, was used to couple the elements of a speedometer made for years by Waltham and used on many of our best cars.

Artificial Lightning

At his Colorado Springs laboratory in 1899 and 1900, Tesla produced artificial lightning crashes of many millions of volts and up to 135 feet long – a feat never since equalled.

Synchronous Electric Clocks

In his talk before the International Electrical Congress, August 25, 1893, at the Chicago Fair, he demonstrated several synchronous electric clocks. In a statement regarding his “World System. of wireless power, made in 1900, he mentioned cheap synchronous clocks all over the world which would be powered and kept in step by a single master generator in the United States. No one put such clocks into commercial use until about 1916.


Though more in the form of prophecy (as there was no equipment at the time capable of carrying it out), Tesla wrote in 1917 of ideas he claims he had many years before in which vessels and other distant objects could be detected by training on them an extremely powerful ray of short-wave electrical impulses and picking up a reflection on a fluorescent screen. Marconi was hailed as the progenitor of this idea when he made a similar, but less detailed, prophecy in 1922 – at a time when there was still no means to effectively carry it out.


As another promise for his “World Wireless,. of 1900, Tesla proposed: “The interconnection and operation of all the telephone exchanges on the globe; the world transmission of typed or hand-written characters, letters, checks, etc.; the in- auguration of a system of world printing; the world reproduction of photographs and all kinds of drawings or records.” Prof. Arthur Korn, who actually sent the first pictures by wireless, credits Tesla with some of his system.


At the turn of the century, Tesla also said this of his system: “I have no doubt that it will prove very efficient in enlightening the masses, particularly in still uncivilized countries and less accessible regions, and that it will add materially to general safety, comfort and convenience, and maintenance of peaceful relations. It involves the employment of a number of plants, all of which are capable of transmitting individualized signals to the uttermost confines of the earth. Each of them will be preferably located near some important center of civilization and the news it receives through any channel will be flashed to all points of the globe. A cheap and simple device, which might be carried in one’s pocket, may then be set up somewhere on sea or land, where it will record the world’s news or such special messages as may be intended for it.”

In an article of appreciation of Tesla’s work, published in the Scientific Monthly, just after Tesla died in 1943, Major E. H. Armstrong quoted the statement above and commented: “Of course the instrumentalities for practicing broadcasting were not then in existence. Tesla was classed as a visionary and his prophecy was forgotten. What harsher terms might, with justice, be applied to many of us who helped produce the instrumentalities with which broadcasting was eventually accomplished’ We applied them to point-to-point communication, failing completely to realize the significance of Tesla’s words.”

July 22, 1960, pp. 6, 8


A Russian publication, Technical Practice, reported that by 1985, electrical power was expected to be delivered to the larger populated areas using neither cable. nor wires. It was also announced that starting in 1965 special reception transformers about the size of a Watt-hour meter would be installed in new housing in the Moscow suburbs.

It was also disclosed in 1955 that the Russians considered the experiment as a failure, according to Swedish observers. The idea was bandied about in the U. S. since Tesla’s time.

The Electrical Engineer – London
June 22, 1888, pp. 583-585


The interest taken in M. Tesla’s contributions to electrical apparatus and to electrical literature is so great, and the subject is so important, that we do not hesitate to give further space to the subject. On May 26 a communication on the subject from Dr. Louis Duncan, of Johns Hopkins University, appeared in our American contemporary, the Electrical Review, to the effect:

“We may, for our present purposes, divide motors into two classes; Continuous, in which the armature coils are unsymmetrical with respect to the poles, and which, therefore, give a practically constant torque, and alternating motors, in which the armature coils are symmetrical with respect to the poles, and which, therefore, give a torque varying both in magnitude and sign during a period of the counter E.M.F. The Tesla motor belongs to this latter class.

“In every motor the torque is equal to the rate of change of lines of induction through the armature circuit for a small angular displacement, multiplied by the armature current, or dm

In the Tesla motor the first of these terms is greatest when the coil is opposite a pole and the field currents have their greatest amplitude. It is zero at a point about 45 deg. from this, supposing we neglect armature reactions. It depends on several things. The E.M.F. which determines it is due to changes in the number of lines of force passing through the armature circuit caused by (1) changes in the field currents; (2) the motion of the armature. The current depends on these E.M.F.’s, and on the reduced self-induction and resistance of its circuit. The motor can only do work when the first cause of E.M.F. is the greater, for a current in the direction of the ordinary counter E.M.F. would stop the motion. In some parts of a revolution the two E.M.F.’s work together, retarding the motion; in others, the induced E.M.F. produces a current causing the motor to revolve. It is impossible for me, with only a meagre description of the principles of the machine, to give an idea of the relative magnitude of these effects. Some of the results, however, are the following: Having given a definite number of reversals of the dynamo, there are a number of speeds, multiples of these reversals, at which the motor will govern itself when it is doing a certain amount of work. At one of these speeds, depending on the construction of the motor, the output will be a maximum. Now I see the statement that ‘there is no difficulty whatever attendant upon starting the motor under load.’ I cannot reconcile this with the above facts. That the torque for a smaller number of revolutions than ordinarily used, might be greater, one can readily see, since the counter E.M.F. is less in proportion to the induced E.M.F., but it must be remembered that for certain speeds even the induced current would tend to stop the motion; how the motor is to pass these critical speeds I do not see. Again, if the maximum load is suddenly thrown on while the motor is running at its proper speed, then, if the inertia be great, the motor will fall behind its point of maximum work, and either stop or take up some slower speed.

“What the possible efficiency and output of the motor may be, only experiment will tell. I have shown* that the output of an ordinary alternating current motor is equal to that of a continuous current motor, supplied with a corresponding E.M.F. The efficiency might be great, but is has the disadvantage that about the same current flows for no work and maximum work, so for light loads the efficiency can hardly be very high.

“With our present knowledge of alternating currents it is useless to attempt to calculate from the simple though misleading assumptions ordinarily made, the

*Inst. Elec. Engineers
Feb., 1888

Experiment alone can determine its value, and one properly conducted and interpreted set of experiments should enable us to judge both the merit of the invention and its best possible form. I cannot see, however, how, in the form described in the last issue of this journal the motor can work under conditions of a suddenly varying load as satisfactorily as continuous current motors.”

To the above Mr. Tesla replied on June 2 as follows:

“I find in your issue of last week a note of Mr. Duncan referring to my system of alternate current motors.

“As I see that Dr. Duncan has not as yet been made acquainted with the real character of my invention, I cannot consider his article in the light of a serious criticism, and would think it unnecessary to respond; but desiring to express my consideration for him and the importance which I attach to his opinion, I will point out here briefly the characteristic features of my invention, inasmuch as they have a direct bearing on the article above referred to.

“The principle of action of my motor will be well understood from the following: By passing alternate currents in proper manner through independent energising circuits in the motor, a progressive shifting or rotation of the poles of the same is effected. This shifting is more or less continuous according to the construction of the motor and the character and relative phase of the currents which should exist in order to secure the most perfect action.

“If a laminated ring be wound with four coils, and the same be connected in proper order to two independent circuits of an alternate current generator adapted for this purpose, the passage of the currents through the coils produces theoretically a rotation of the poles of the ring, and in actual practice, in a series of experiments, I have demonstrated the complete analogy between such a ring and a revolving magnet. From the application of this principle to the operation of motors, two forms of motor of a character widely differing have resulted [in] one designed for constant and the other for variable load. The misunderstanding of Dr. Duncan is due to the fact that the prominent features of each of these two forms have not been specifically stated. In illustration of a representative of the second class, I refer to Fig. 1, given herewith. In this instance, the armature of the motor is provided with two coils at right angles. As it may be believed that a symmetrical arrangement of the coils with respect to the poles is required, I will assume that the armature is provided with a great number of diametrically wound coils or conductors closed upon themselves, and forming as many independent circuits. Let it now be supposed that the ring is permanently magnetized so as to show two poles (N and S) at two points diametrically opposite, and that it is rotated by mechanical power. The armature being stationary, the rotation of the ring magnet will set up currents in the closed armature coils. These currents will be most intense at or near the points of the greatest density of the force, and they will produce poles upon the armature core at right angles to those of the ring. Of course there will be other elements entering into action which will tend to modify this, but for the present they may be left unconsidered. As far as the location of the poles upon the armature core is concerned, the currents generated in the armature coils will always act in the same manner, and will maintain continuously the poles of the core in the same position, with respect to those of the ring in any position of the latter, and independently of the speed. From the attraction between the core and the ring, a continuous rotary effort, constant in all positions, will result, the same as in a continuous current motor with a great number of armature coils. If the armature be allowed to turn, it will revolve in the direction of rotation of the ring magnet, the induced current diminishing as the speed increases, until upon the armature reaching very nearly the speed of the magnet, just enough current will flow through the coils to keep up the rotation. If, instead of rotating the ring by mechanical power, the poles of the same are shifted by the action of the alternate currents in the two circuits, the same results are obtained.

“Now compare this system with a continuous current system. In the latter we have alternate currents in the generator and motor coils, and intervening devices for commutating the currents, which on the motor besides effect automatically a progressive shifting or rotation of the poles of the armature; here we have the same elements and identically the same operation, but without the commutating devices. In view of the fact that these devices are entirely unessential to the operation, such alternate current system will – at least in many respects – show a complete similarity with a continuous current system, and the motor will act precisely like a continuous current motor. If the load is augmented, the speed is diminished and the rotary effort correspondingly increased, as more current is made to pass through the energising circuits; load being taken off, the speed increases, and the current, and consequently the effort, is lessened. The effort, of course, is greatest when the armature is in the state of rest.

“But, since the analogy is complete, how about the maximum efficiency and current passing through the circuits when the motor is running without any load? one will naturally inquire. It must be remembered that we have to deal with alternate currents. In this form the motor simply represents a transformer, in which currents are induced by a dynamic action instead of by reversals, and, as it might be expected, the efficiency will be maximum at full load. As regards the current, there will be – at least, under proper conditions – as wide a variation in its strength as in a transformer, and, by observing proper rules, it may be reduced to any desired quantity. Moreover, the current passing through the motor when running free, is no measure for the energy absorbed, since the instruments indicate only the numerical sum of the direct and induced electromotive forces and currents instead of showing their difference.

“Regarding the other class of these motors, designed for constant speed, the objections of Dr. Duncan are, in a measure applicable to certain constructions, but it should be considered that such motors are not expected to run without any, or with a very light load; and, if so, they do not, when properly constructed, present in this respect any more disadvantage than transformers under similar conditions. Besides, both features, rotary effort and tendency to constant speed, may be combined in a motor, and any desired preponderance may be given to either one, and in this manner a motor may be obtained possessing any desired character and capable of satisfying any possible demand in practice.

“In conclusion, I will remark, with all respect to Dr. Duncan, that the advantages claimed for my system are not mere assumptions, but results actually obtained, and that for this purpose experiments have been conducted through a long period, and with an assiduity such as only a deep interest in the invention could inspire; nevertheless, although my motor is the fruit of long labour and careful investigation, I do not wish to claim any other merit beyond that of having invented it, and I leave it to men more competent than myself to determine the true laws of

the principle and the best mode of its application. What the result of these investigations will be the future will tell; but whatever they may be, and to whatever this principle may lead, I shall be sufficiently recompensed if later it will be admitted that I have contributed a share, however small, to the advancement of science.”

Electrical World – N. Y.
May 25, 1889, pp. 297-298.


To the Editor of The Electrical World:

SIR: About a year ago I had the pleasure of bringing before the American Institute of Electrical Engineers the results of some of my work on alternate current motors. They were received with the interest which novel ideas never fail to excite in scientific circles, and elicited considerable comment. With truly American generosity, for which, on my part, I am ever thankful, a great deal of praise through the columns of your esteemed paper and other journals has been bestowed upon the originator of the idea, in itself insignificant. At that time it was impossible for me to bring before the Institute other results in the same line of thought. Moreover, I did not think it probable – considering the novelty of the idea – that anybody else would be likely to pursue work in the same direction. By one of the most curious coincidences, however, Professor Ferraris not only came independently to the same theoretical results, but in a manner identical almost to the smallest detail. Far from being disappointed at being prevented from calling the discovery of the principle exclusively my own, I have been excessively pleased to see my views, which I had formed and carried out long before, confirmed by this eminent man, to whom I consider myself happy to be related in spirit, and toward whom, ever since the knowledge of the facts has reached me, I have entertained feelings of the most sincere sympathy and esteem. In his able essay Prof. Ferraris omitted to mention various other ways of accomplishing similar results, some of which have later been indicated by O. B. Shallenberger, who some time before the publication of the results obtained by Prof. Ferraris and myself had utilized the principle in the construction of his now well known alternate current meter, and at a still later period by Prof. Elihu Thomson and Mr. M. J. Wightman.

Since the original publications, for obvious reasons, little has been made known in regard to the further progress of the invention; nevertheless the work of perfecting has been carried on indefatigably with all the intelligent help and means which a corporation almost unlimited in its resources could command, and marked progress has been made in every direction. It is therefore not surprising that many unacquainted with this fact, in expressing their views as to the results obtained, have grossly erred.

In your issue of May 4 I find a communication from the electricians of Ganz & Co., of Budapest, relating to certain results observed in recent experiments with a novel form of alternate current motor. I would have nothing to say in regard to this communication unless it were to sincerely congratulate these gentlemen on any good results which they may have obtained, but for the article, seemingly inspired by them, which appeared in the London Electrical Review of April 26, wherein certain erroneous views are endorsed and some radically false assertions made, which, though they may be quite unintentional, are such as to create prejudice and affect material interests.

As to the results presented, they not only do not show anything extraordinary, but are, in fact, considerably below some figures obtained with my motors a long time ago. The main stress being laid upon the proposition between the apparent and real energy supplied, or perhaps more directly, upon the ratio of the energy apparently supplied to, and the real energy developed by, the motor, I will here submit, with your permission, to your readers, the results respectively arrived at by these gentlemen and myself.

Energy apparently Ratio of energy apparently supplied
supplied in watts. Work performed into the real energy
watts. developed.

Ganz & Westing- Ganz & Westing- Ganz & Westing-
Co. house Co. Co. house Co. Co. house Co.

18,000 21,840 11,000 17,595 0.611 0.805
24,200 30,295 14,600 25,365 0.603 0.836
29,800 43,624 22,700 36,915 0.761 0.816

….. 56,800 ….. 48,675 …. 0.856
….. 67,500 ….. 59,440 …. 0.88
….. 79,100 ….. 67,365 …. 0.851

If we compare these figures we will find that the most favorable ratio in Ganz & Co’s motor is 0.761, whereas in the Westinghouse, for about the same load, it is 0.836, while in other instances, as may be seen, it is still more favorable. Notwithstanding this, the conditions of the test were not such as to warrant the best possible results.

The factors upon which the apparent energy is mainly dependent could have been better determined by a proper construction of the motor and observance of certain conditions. In fact, with such a motor a current regulation may be obtained which, for all practical purposes, is as good as that of the direct current motors, and the only disadvantage, if it be one, is that when the motor is running without load the apparent energy cannot be reduced quite as low as might be desirable. For instance, in the case of this motor the smallest amount of apparent energy was about 3,000 watts, which is certainly not very much for a machine capable of developing 90 h. p. of work; besides, the amount could have been reduced very likely to 2,000 watts or less.

On the other hand, these motors possess the beautiful feature of maintaining an absolutely constant speed no matter how the load may vary. This feature may be illustrated best by the following experiment performed with this motor. The motor was run empty, and a load of about 200 h. p., far exceeding the normal load, was thrown on suddenly. Both armatures of the motor and generator were seen to stop for an instant, the belts slipping over the pulleys, whereupon both came up to the normal speed with the full load, not having been thrown out of synchronism. The experiment could be repeated any number of times. In some cases, the driving power being sufficient, I have been enabled to throw on a load exceeding 8 to 9 times that which the motor was designed to carry, without affecting the speed in the least.

This will be easily understood from the manner in which the current regulation is effected. Assuming the motor to be running without any load, the poles of the armature and field have a certain relative position which is that of the highest self-induction or counter electromotive force. If load be thrown on, the poles are made to recede; the self-induction or counter electromotive force is thereby diminished and more current passed through the stationary or movable armature-coils. This regulation is very different from that of a direct current motor. In the latter the current is varied by the motor losing a certain number of revolutions in proportion to the load, and the regulation would be impossible if the speed would be maintained constant; here the whole regulation is practically effected during a fraction of one revolution only. From this it is also apparent that it is a practical impossibility to throw such a motor out of synchronism, as the whole work must be done in an instant, it being evident that if the load is not sufficient to make a motor lose a fraction of the first revolution it will not be able to do so in the succeeding revolutions. As to the efficiency of these motors, it is perfectly practicable to obtain 94 to 95 per cent.

The results above given were obtained on a three-wire system. The same motor has been started and operated on two wires in a variety of ways, and although it was not capable of performing quite as much work as on three wires, up to about 60 h. p. it gave results practically the same as those above-mentioned. In fairness to the electricians of Ganz & Co., I must state here that the speed of this motor was higher than that used in their experiments, it being about 1,500. I cannot make due allowance for this difference, as the diameter of the armature and other particulars of the Ganz & Co. motor were not given.

The motor tested had a weight of about 5,000 lbs. From this it will be seen that the performance even on two wires was quite equal to that of the best direct current motors. The motor being of a synchronous type, it might be implied that it was not capable of starting. On the contrary, however, it had a considerable torque on the start and was capable of starting under fair load.

In the article above referred to the assertion is made that the weight of such alternate current motor, for a given capacity, is “several times” larger than that of a direct current motor. In answer to this I will state here that we have motors which with a weight of about 850 pounds develop 10 h. p. with an efficiency of very nearly 90 per cent, and the spectacle of a direct current motor weighing, say 200 – 300 pounds and performing the same work, would be very gratifying for me to behold. The motor which I have just mentioned had no commutator or brushes of any kind nor did it require any direct current.

Finally, in order to refute various assertions made at random, principally in the foreign papers, I will take the liberty of calling to the attention of the critics the fact that since the discovery of the principle several types of motors have been perfected and of entirely different characteristics, each suited for a special kind of work, so that while one may be preferable on account of its ideal simplicity, another might be more efficient. It is evidently impossible to unite all imaginable advantages in one form, and it is equally unfair and unreasonable to judge all different forms according to a common standard. Which form of the existing motors is best, time will show; but even in the present state of the art we are enabled to satisfy any possible demand in practice.

Nikola Tesla

Pittsburgh, Pa.

The Electrical Engineer – N. Y.
April 9, 1890, p. 221


In your issue of April 2, in referring to certain remarks made by me at the recent meeting of the American Institute of Electrical Engineers on the subject of hysteresis you make the statement: “It is this constancy of relation that, as Mr. Tesla pointed out * * * may ultimately establish the correctness of the hypothesis advanced, that in reality there is no loss due to hysteresis, and that the changes of magnetization represent a charging and discharging of molecular energy without entailing an actual expenditure of energy.”

I do not recollect having made such a statement, and as I was evidently misunderstood, you will greatly oblige me in inserting the following few lines, which express the idea I meant to advance:

Up to the present no satisfactory explanation of the causes of hysteresis has been given. In the most exhaustive and competent treatise on the theory of transformers, by Fleming, static hysteresis is explained by supposing that “the magnetic molecules or molecular magnets, the arrangement of which constitutes magnetization, move stiffly, and the dissipation of energy is the work done in making the necessary magnetic displacement against a sort of magnetic friction.” Commonly it is stated that this is a distinct element in the loss of energy in an iron core undergoing magnetic changes entirely independent of any currents generated therein.

Now it is difficult to reconcile these views with our present notions on the constitution of matter generally. The molecules or iron cannot be connected together by anything but elastic forces, since they are separated by an intervening elastic medium through which the forces act; and this being the case is it not reasonable to assume that if a given amount of energy is taken up to bring the molecules out of their original position an equivalent amount of energy should be restored by the molecules reassuming their original positions, as we know is the case in all molecular displacements? We cannot imagine that an appreciable amount of energy should be wasted by the elastically connected molecules swinging back and forth from their original positions, which they must constantly tend to assume, at least within the limit of elasticity, which in all probability is rarely surpassed. The losses cannot be attributed to mere displacement, as this would necessitate the supposition that the molecules are connected rigidly, which is quite unthinkable.

A current cannot act upon the particles unless it acts upon currents in the same, either previously existing or set up by it, and since the particles are held together by elastic forces the losses must be ascribed wholly to the current generated. The remarkable discovery of Ewing that the magnetization is greater on the descent than on the ascent for the same values of magnetizing force strongly points to the fact that hysteresis is intimately connected with the generation of currents either in the molecules individually or in groups of them through the space intervening. The fact observed accords perfectly with our experience on current induction, for we know that on the descent any current set up must be of the same direction with the inducing current, and, therefore, must join with the same in producing a common effect; whereas, on the ascent the contrary is the case.

Dr. Duncan stated that the ratio of increase of primary and secondary current is constant. This statement is, perhaps, not sufficiently expressive, for not only is the ratio constant but, obviously, the differential effect of primary and secondary is constant. Now any current generated – molecular or Foucault currents in the mass – must be in amount proportionate to the difference of the inductive effect of the primary and secondary, since both currents add algebraically – the ratio of windings duly considered, – and as this difference is constant the loss, if wholly accounted for in this manner, must be constant. Obviously I mean here the transformers under consideration, that is, those with a closed magnetic circuit, and I venture to say that the above will be more pronounced when the primary and secondary are wound one on top of the other than when they are wound side by side; and generally it will be the more pronounced the closer their inductive relation.

Dr. Duncan’s figures also show that the loss is proportionate to the square of the electromotive force. Again this ought to be so, for an increased electromotive force causes a proportionately increased current which, in accordance with the above statements, must entail a loss in the proportion of the square.

Certainly, to account for all the phenomena of hysteresis, effects of mechanical vibration, the behavior of steel and nickel alloy, etc., a number of suppositions must be made; but can it not be assumed that, for instance, in the case of steel and nickel alloys the dissipation of energy is modified by the modified resistance; and to explain the apparent inconsistency of this view we only need to remember that the resistance of a body as a whole is not a measure of the degree of conductivity of the particles of which it is composed.

N. Tesla
New York City

The Electrical Engineer – London
April 3, 1891, p. 345


Sir – In your issue of March 6 I find the passage: “Mr. Kapp described the position as it exists. He showed how Ferraris first of all pointed out the right way to get an alternating-current motor that was self-starting, and how Tesla and others had worked in the direction indicated by Ferraris,” etc.

I would be very glad to learn how Mr. Kapp succeeded in showing this. I may call his attention to the fact that the date of filing of my American patent anticipates the publication of the results of Prof. Ferraris in Italy by something like six months. The date of filing of my application is, therefore, the first public record of the invention. Considering this fact, it seems to me that it would be desirable that Mr. Kapp should modify his statement. – Yours, etc.

New York, 17th March , 1891.

The Detroit Free Press

Feb. 16, 1896, p. 16.


Some weeks ago this journal published an interesting article concerning electrical oscillations as observed by the eminent scientist, NIKOLA Tesla. So much interest was shown in the subject that Mr. Tesla was appealed to directly and in response to that appeal he sends to The Detroit Free Press this open letter:

Nos. 46 & 48 E. Houston Street
New York, February 10, 1896

During the past few weeks I have received so many letters concerning the same subject that it was entirely beyond my power to answer all of them individually. In view of this I hope that I shall be excused for the delay, which I must regret, in acknowledging the receipt, and also for addressing this general communication in answer to all inquiries.

The many pressing demands which have been made upon me in consequence of exaggerated statements of the journals have painfully impressed me with the fact that there are a great many sufferers, and furthermore that nothing finds a more powerful echo than a promise held out to improve the condition of the unfortunate ones.

The members of the medical fraternity are naturally more deeply interested in the task of relieving the suffering from their pain, and, as might be expected, a great many communications have been addressed to me by physicians. To these chiefly this brief statement of the actual facts is addressed.

Some journals have confounded the physiological effects of electrical oscillations with those of mechanical vibrations, this being probably due to the circumstance that a few years ago I brought to the attention of the scientific men some novel methods and apparatus for the production of electrical oscillations which, I learn, are now largely used in some modification or other in electro-therapeutic treatment and otherwise. To dispel this erroneous idea I wish to state that the effects of purely mechanical vibrations which I have more recently observed, have nothing to do with the former.

Mechanical vibrations have often been employed locally with pronounced results in the treatment of diseases, but it seems that the effects I refer to have either not been noted at all, or if so, only to a small degree, evidently because of the insufficiency of the means which have eventually been employed in the investigations.

While experimenting with a novel contrivance, constituting in its simplest form a vibrating mechanical system, in which from the nature of the construction the applied force is always in resonance with the natural period, I frequently exposed my body to continued mechanical vibrations. As the elastic force can be made as large as desired, and the applied force used be very small, great weights, half a dozen persons, for instance, may be vibrated with great rapidity by a comparatively small apparatus.

I observed that such intense mechanical vibrations produce remarkable physiological effects. They affect powerfully the condition of the stomach, undoubtedly promoting the process of digestion and relieving the feeling of distress, often experienced in consequence of the imperfect function of the organs concerned in the process. They have a strong influence upon the liver, causing it to discharge freely, similarly to an application of a catharic. They also seem to affect the glandular system, noteably in the limbs; also the kidneys and bladder, and more or less influence the whole body. When applied for a longer period they produce a feeling of immense fatigue, so that a profound sleep is induced.

The excessive tiring of the body is generally accompanied by nervous relaxation, but there seems to be besides a specific action on the nerves.

These observations, though incomplete, are, in my own limited judgment, nevertheless positive and unmistakable, and in view of this and of the importance of further investigation of the subject by competent men I prepared about a year ago a machine with suitable adjustments for varying the frequency and amplitude of the vibrations, intending to give it to some medical faculty for investigation. This machine, together with other apparatus, was unfortunately destroyed by fire a year ago, but will be reconstructed as soon as possible.

In making the above statements I wish to disconnect myself with the extraordinary opinions expressed in some journals which I have never authorized and which, though they may have been made with good intent, cannot fail to be hurtful by giving rise to visionary expectations.

Yours very truly,

N. Tesla

Electrical Review- N. Y.
March 18, 1896, p. 147



To The Editor of Electrical Review:

Permit me to say that I was slightly disappointed to note in your issue of Mar. 11 the prominence you have deemed to accord to my youth and talent, while the ribs and other particulars of Fig. 1, which, with reference to the print accompanying my communication, I described as clearly visible, were kept modestly in the background. I also regretted to observe an error in one of the captions, the more so, as I must ascribe it to my own text. I namely stated on page 135, third column, seventh line: “A similar impression was obtained through the body of the experimenter, etc., through a distance of four feet.” The impression here referred to was a similar one to that shown in Fig. 2, whereas the shadow in Fig. 1 was taken through a distance of 18 inches. I state this merely for the sake of correctness of my communication, but, as far as the general truth of the fact of taking such a shadow at the distance given is concerned, your caption might as well stand, for I am producing strong shadows at distances of 40 feet. I repeat, 40 feet and even more. Nor is this all. So strong are the actions on the film that provisions must be made to guard the plates in my photographic department, located on the floor above, a distance of fully 60 feet, from being spoiled by long exposure to the stray rays. Though during my investigations I have performed many experiments which seemed extraordinary, I am deeply astonished observing these unexpected manifestations, and still more so, as even now I see before me the possibility, not to say certitude, of augmenting the effects with my apparatus at least tenfold! What may we then expect? We have to deal here, evidently, with a radiation of astonishing power, and the inquiry into its nature becomes more and more interesting and important.

Here is an unlooked-for result of an action which, though wonderful in itself, seemed feeble and entirely incapable of such expansion, and affords a good example of the fruitfulness of original discovery. These effects upon the sensitive plate at so great a distance I attribute to the employment of a bulb with a single terminal, which permits the use of practically any desired potential and the attainment of extraordinary speeds of the projected particles. With such a bulb it is also evident that the action upon a fluorescent screen is proportionately greater than when the usual kind of tube is employed, and I have already observed enough to feel sure that great developments are to be looked for in this direction. I consider Roentgen’s discovery, of enabling us to see, by the use of a fluorescent screen, through an opaque substance, even a more beautiful one than the recording upon the plate.

Since my previous communication to you I have made considerable progress, and can presently announce one more result of importance. I have lately obtained shadows by reflected rays only, thus demonstrating beyond doubt that the Roentgen rays possess this property. One of the experiments may be cited here. A thick copper tube, about a foot long, was taken and one of its ends tightly closed by the plate-holder containing a sensitive plate, protected by a fiber cover as usual. Near the open end of the copper tube was placed a thick plate of glass at an angle of 45 degrees to the axis of the tube. A single-terminal bulb was then suspended above the glass plate at a distance of about eight inches, so that the bundle of rays fell upon the latter at an angle of 45 degrees, and the supposedly reflected rays passed along the axis of the copper tube. An exposure of 45 minutes gave a clear and sharp shadow of a metallic object. This shadow was produced by the reflected rays, as the direct action was absolutely excluded, it having been demonstrated that even under the severest tests with much stronger actions no impression whatever could be produced upon the film through a thickness of copper equal to that of the tube. Concluding from the intensity of the action by comparison with an equivalent effect due to the direct rays, I find that approximately two per cent of the latter were were reflected from the glass plate in this experiment. I hope to be able to report shortly and more fully on this and other subjects.

In my attempts to contribute my humble share to the knowledge of the Roentgen phenomena, I am finding more and more evidence in support of the theory of moving material particles. It is not my intention, however, to advance at present any view as to the bearing of such a fact upon the present theory of light, but I merely seek to establish the fact of the existence of such material streams in so far as these isolated effects are concerned. I have already a great many indications of a bombardment occurring outside of the bulb, and I am arranging some crucial tests which, I hope, will be successful. The calculated velocities fully account for actions at distances of as much as 100 feet from the bulb, and that the projection through the glass takes place seems evident from the process of exhaustion, which I have described in my previous communication. An experiment which is illustrative in this respect, and which I intended to mention, is the following; If we attach a fairly exhausted bulb containing an electrode to the terminal of a disruptive coil, we observe small streamers breaking through the side of the glass. Usually such a streamer will break through the seal and crack the bulb, whereupon the vacuum is impaired; but, if the seal is placed above the terminal, or if some other provision is made to prevent the streamer from passing through the glass at that point, it often occurs that the stream breaks out through the side of the bulb, producing a fine hole. Now, the extraordinary thing is that, in spite of the connection to the outer atmosphere, the air can not rush into the bulb as long as the hole is very small. The glass at the place where the rupture has occurred may grow very hot – to such a degree as to soften; but it will not collapse, but rather bulge out, showing that a pressure from the inside greater than that of the atmosphere exists. On frequent occasions I have observed that the glass bulges out and the hole, through which the streamer rushes out, becomes so large as to be perfectly discernible to the eye. As the matter is expelled from the bulb the rarefaction increases and the streamer becomes less and less intense, whereupon the glass closes again, hermetically sealing the opening. The process of rarefaction, nevertheless, continues, streamers being still visible on the heated place until the highest degree of exhaustion is reached, whereupon they may disappear. Here, then, we have a positive evidence that matter is being expelled through the walls of the glass.

When working with highly strained bulbs I frequently experience a sudden, and sometimes even painful, shock in the eye. Such shocks may occur so often that the eye gets inflamed, and one can not be considered over-cautious if he abstains from watching the bulb too closely. I see in these shocks a further evidence of larger particles being thrown off from the bulb.

Nikola Tesla.

New York, March 14.

The Electrical Engineer – N. Y.
December 23, 1896, p. 655


In a letter to the editor of the Buffalo Enquirer, Mr. Nikola Tesla replies as follows in regard to an inquiry on the subject of the future of electricity:

“The transmission of power has interested me not only as a technical problem, but far more in its bearing upon the welfare of mankind. In this sense I have expressed myself in a lecture, delivered some time ago.

“Since electrical transmission of energy is a process much more economical than any other we know of, it necessarily must play an important part in the future, no matter how the primary energy is derived from the sun. Of all the ways the utilization of a waterfall seems to be the simplest and least wasteful. Even if we could, by combining carbon in a battery, convert the work of the chemical combination into electrical energy with very high economy, such mode of obtaining power would, in my opinion, be no more than a mere makeshift, bound to be replaced sooner or later by a more perfect method, which implies no consumption of any material whatever.”

Cassiers Magazine – London
March, 1897, pp. 378-386.


by Nikola Tesla

The commemoration of the recent introduction into the city of Buffalo of electric power from Niagara Falls was made the occasion of a banquet, held at the Ellicott Club, at Buffalo on January 12, 1897, the hosts being the Niagara Falls Power and Conduit Company, and the distinguished guests the men, principally, to whose business and engineering talents the world owes the remarkable Niagara undertaking so recently brought to successful completion. Probably none among these has been more honoured than Mr. Nikola Tesla, whose electrical researches and practical accomplishments have been the talk of the world, and whose polyphase alternating current system was the one eventually adopted in the work at Niagara Falls. After the banquet, in responding to the toast, “Electricity,” Mr. Tesla spoke at length of the various sciences, with special reference, naturally to electricity, and from his remarks the appended extracts have been made, picturing in a graphic and striking manner the dependence upon power of the development and wealth of cities, the success of nations, the progress of the whole human race, in fact, as he himself put it. – THE EDITOR.

For more than half a century the steam engine has served the innumerable wants of man. The work it was called to perform was of such variety, and the conditions in each case were so different that, of necessity, a great many types of engines resulted. In the vast majority of cases the problem put before the engineer was not, as it should have been, the broad one of converting the greatest possible amount of heat energy into mechanical power, but it was rather the specific problem of obtaining the mechanical power in such form as to be best suitable for general use. As the reciprocating motion of the piston was not convenient for practical purposes, except in very few instances, the piston was connected to a crank, and thus rotating motion was obtained, which was more suitable and preferable, though it involved numerous disadvantages incident to the crude and wasteful means employed. But until quite recently there were at the disposal of the engineer, for the transformation and transmission of the motion of the piston, no better means than rigid mechanical connections.

The past few years have brought forcibly to the attention of the builder the electric motor, with its ideal features. Here was a mode of transmitting mechanical motion, simpler by far, and also much more economical. Had this mode been – perfected earlier, there can be no doubt that the majority of the many types of engines would not exist, for just as soon as an engine was coupled with an electric generator a type was produced capable of almost universal use. From this moment on there was no necessity to endeavor to perfect engines of special designs capable of doing special kinds of work. The engineer’s task became now to concentrate all his efforts upon one type, to perfect one kind of engine – the best, the universal, the engine of the immediate future; namely, the one which is best suitable for the generation of electricity.

The first efforts in this direction gave a strong impetus to the development of the reciprocating high-speed engine, and also to the turbine, which latter was a type of engine of very limited practical usefulness, but became, to a certain extent, valuable in connection with the electric generator and motor. Still, even the former engine, though improved in many particulars, is not radically changed, and even now has the same objectionable features and limitations. To do away with these as much as possible, a new type of engine is being perfected in which more favourable conditions for economy are maintained, which expands the working fluid with utmost rapidity and loses little heat on the walls of the engine stripped of all usual regulating mechanism – packings, oilers and other appendages – and forming part of an electric generator; and in this type, I may say, I have implicit faith.

The gas or explosive engine has been likewise profoundly affected by the commercial introduction of electric light and power, particularly in quite recent years. The engineer is turning his energies more and more in this direction, being attracted by the prospect of obtaining a higher thermodynamic efficiency. Much larger engines are now being built, the construction is constantly improved, and a novel type of engine, best suitable for the generation of electricity, is being rapidly evolved.

There are many other lines of manufacture and industry in which the influence of electrical development has been even more powerfully felt, – for instance, the manufacture of a great variety of articles of metal, and especially of chemical products. The welding of metals by electricity, though involving a wasteful process, has, nevertheless, been accepted as a legitimate art, while the manufacture of metal sheet, seamless tubes and the like affords promise of much improvement.

We are coming gradually, but surely, to the fusion of bodies and reduction of all kinds of ores – even of iron ores – by the use of electricity, and in each of these departments great realisations are probable. Again, the economical conversion of ordinary currents of supply into high-frequency currents opens up new possibilities, such as the combination of the atmospheric nitrogen and the production of its compounds; for instance, ammonia and nitric acid, and their salts, by novel processes.

To enumerate the many advances recorded is a subject for the reviewer, but I cannot pass without mentioning the beautiful discoveries of Lenard and Roentgen, particularly the latter, which have found such a powerful response throughout the scientific world that they have made us forget, for a time, the great achievement of Linde in Germany, who has effected the liquefaction of air on an industrial scale by a process of continuous cooling; the discovery of argon by Lord Raleigh and Professor Ramsay, and the splendid pioneer work of Professor Dewar in the field of low temperature research. The fact that the United States have contributed a very liberal share to this prodigious progress must afford to all of us great satisfaction.

While honouring the workers in other countries and all those who, by profession or inclination, are devoting themselves to strictly scientific pursuits, Americans have particular reasons to mention with gratitude the names of those who so much contributed to this marvelous development of electrical industry in the United States. Bell, who, by his admirable invention enabling us to transmit speech to great distances, has profoundly affected our commercial and social relations, and even our very mode of life; Edison, who, had he not done anything else beyond his early work in incandescent lighting, would have proved himself one of the greatest benefactors of the age; Westinghouse, the founder of the commercial alternating system; Brush, the great pioneer of arc lighting; Thomson, who gave us the first practical welding machine, and who, with keen sense, contributed very materially to the development of a number of scientific and industrial branches; Weston, who once led the world in dynamo design, and now leads in the construction of electric instruments; Sprague, who, with rare energy, mastered the problem and insured the success of practical electrical railroading; Acheson, Hall, Willson and others, who are creating new and revolutionising industries here under our very eyes at Niagara.

Nor is the work of these gifted men nearly finished at this hour. Much more is still to come, for fortunately, most of them are still full of enthusiasm and vigor. All of these men and many more are untiringly at work investigating new regions and opening up unsuspected and promising fields. Weekly, if not daily, we learn through the journals of a new advance into some unexplored region, where at every step success beckons friendly, and leads the toiler on to hard and harder tasks.

But among all these many departments of research, these many branches of industry, new and old, which are being rapidly expanded, there is one dominating all others in importance – one which is of the greatest significance for the comfort and welfare, not to say for the existence, of mankind, and that is the electrical transmission of power. And in this most important of all fields long afterwards, when time will have placed the events in their proper perspective, and assigned men to their deserved places, the great event we are commemorating to-day will stand out as designating a new and glorious epoch in the history of humanity – an epoch grander than that marked by the advent of the steam engine.

We have many a monument of past ages; we have the palaces and pyramids; the temples of the Greek and the cathedrals of Christendom. In them is exemplified the power of men, the greatness of nations, the love of art and religious devotion. But that monument at Niagara has something of its own, more in accord with our present thoughts and tendencies. It is a monument worthy of our scientific age, a true monument of enlightenment and of peace. It signifies the subjugation of natural forces to the service of man, the discontinuance of barbarous methods, the relieving of millions from want and suffering.

No matter what we attempt to do, no matter to what fields we turn our efforts, we are dependent on power. Our economists may propose more economical systems of administration and utilisation of resources, our legislators may make wiser laws and treaties, it matters little; that kind of help can be only temporary. If we want to reduce poverty and misery, if we want to give to every deserving individual what is needed for a safe existence of an intelligent being, we want to provide more machinery, more power. Power is our mainstay, the primary source of our many-sided energies. With sufficient power at our disposal we can satisfy most of our wants and offer a guaranty for safe and comfortable existence to all, except perhaps to those who are the greatest criminals of all – the voluntarily idle.

The development and wealth of a city, the success of a nation, the progress of the whole human race, is regulated by the power available. Think of the victorious march of the British’ Apart from the qualities of the race, which have been of great moment, they owe the conquest of the world to – coal. For with coal they produce their iron; coal furnishes them light and heat; coal drives the wheels of their immense manufacturing establishments, and coal propels their conquering fleets. But the stores are being more and more exhausted, and labour is getting dearer and dearer, and the demand is continuously increasing.

It must be clear to every one that soon some new source of power supply must be opened up, or that at least the present methods must be materially improved. A great deal is expected from a more economical utilisation of the stored energy of the carbon in a battery; but while the attainment of such a result would be hailed as a great achievement, it would not be as much of an advance towards the ultimate and permanent method of obtaining power as some engineers seem to believe. By reason both of economy and convenience we are driven to the general adoption of a system of energy supply from central stations, and for such purposes the beauties of the mechanical generation of electricity cannot be exaggerated. The advantages of this universally accepted method are certainly so great that the probability of replacing the engine dynamos by batteries is, in my opinion, a remote one, the more so as the high-pressure steam engine and gas engine give promise of a considerably more economical thermodynamic conversion.

Even if we had this day such an economical coal battery, its introduction in central stations would by no means be assured, as its use would entail many inconveniences and drawbacks. Very likely the carbon could not be burned in its natural form as in a boiler, but would have to be specially prepared to secure uniformity in the current generation. A great many cells would be needed to make up the electromotive force usually required. The process of cleaning and renewal, the handling of nasty fluids and gases and the great space necessary for so many batteries would make it difficult, if not commercially unprofitable, to operate such a plant in a city or densely populated district.

Again, if the station be erected in the outskirts, the conversion by rotating transformers or otherwise would be a serious and unavoidable drawback. Furthermore, the regulating appliances and other accessories which would have to be provided would probably make the plant fully as much, if not more, complicated than the present. We might, of course, place the batteries at or near the coal mine, and from there transmit the energy to distant points in the form of high-tension alternating currents obtained from rotating transformers, but even in this most favourable case the process would be a barbarous one, certainly more so than the present, as it would still involve the consumption of material, while, at the same time, it would restrict the engineer and mechanic in the exercise of their beautiful art. As to the energy supply in small isolated places, as dwellings, I have placed my confidence in the development of a light storage battery, involving the use of chemicals, manufactured by cheap water power, such as some carbide of oxygen-hydrogen cell.

But we shall not satisfy ourselves simply with improving steam and explosive engines or inventing new batteries; we have something much better to work for, a greater task to fulfill. We have to evolve means for obtaining energy from stores which are forever inexhaustible, to perfect methods which do not imply consumption and waste of any material whatever. Upon this great possibility, upon this great problem, the practical solution of which means so much for humanity, I have myself concentrated my efforts for a number of years, and a few happy ideas which came to me have inspired me to attempt the most difficult, and given me strength and courage in adversity.

Nearly six years ago my confidence had become strong enough to prompt me to an expression of hope in the ultimate solution of this all-dominating problem. I have made progress since, and have passed the stage of mere conviction such as is derived from a diligent study of known facts, conclusions and calculations. I now feel sure that the realisation of that idea is not far off. But precisely for this reason I feel impelled to point out here an important fact, which I hope will be remembered.

Having examined for a long time the possibilities of the development I refer to, namely, that of the operation of engines on any point of the earth by the energy of the medium, I find that even under the theoretically best conditions such a method of obtaining power cannot equal in economy, simplicity and many other features the present method, involving a conversion of the mechanical energy of running water into electrical energy and the transmission of the latter in the form of currents of very high tension to great distances. Provided, therefore, that we can avail ourselves of currents of sufficiently high tension, a waterfall affords us the most advantageous means of getting power from the sun sufficient for all our wants, and this recognition has impressed me strongly with the future importance of the water power, not so much because of its commercial value, though it may be very great, but chiefly because of its bearing upon our safety and welfare.

I am glad to say that also in this latter direction my efforts have not been unsuccessful, for I have devised means which will allow us the use in power transmission of electro-motive forces much higher than those practicable with ordinary apparatus. In fact, progress in this field has given me fresh hope that I shall see the fulfillment of one of my fondest dreams; namely, the transmission of power from station to station without the employment of any connecting wire. Still, whatever method of transmission be ultimately adopted, nearness to the source of power will remain an important advantage.

Some of the ideas I have expressed may appear to many hardly realisable; nevertheless, they are the result of long continued thought and work. With ideas it is as with dizzy heights. At first they cause you discomfort and you are anxious to get down, distrustful of your own powers; but soon the remoteness of the turmoil of life and the inspiring influence of the altitude calm your blood; your step gets firm and sure and you begin to look – for dizzier heights.

In the great enterprise at Niagara we see not only a bold engineering and commercial feat, but far more, a giant stride in the right direction as indicated both by exact science and philanthropy. Its success is a signal for the utilisation of water powers all over the world, and its influence upon industrial development is incalculable. We must all rejoice in the great achievement and congratulate the intrepid pioneers who have joined their efforts and means of bring it about. It is a pleasure to learn of the friendly attitude of the citizens of Buffalo and of the encouragement given to the enterprise by the Canadian authorities. We shall hope that other cities, like Rochester on this side and Hamilton and Toronto in Canada, will soon follow Buffalo’s lead. This fortunate city herself is to be congratulated. With resources now unequalled, with commercial facilities and advantages such as few cities in the world possess, and with the enthusiasm and progressive spirit of its citizens, it is sure to become one of the greatest industrial centres of the globe.

Electrical Review – N. Y.
Jan. 5, 1898, pp. 8, 9



To the Editor of Electrical Review:

A few years ago I began a series of experiments with a view of ascertaining the applicability of the light emitted by phosphorescent vacuum tubes to ordinary photography. The results soon showed that, even with a tube giving no more light than the equivalent of one half of a candle, objects could be easily photographed with exposures of a few minutes, and the time could be reduced at will by pushing the tube to a high candlepower. Photographs of persons were likewise obtained at that time and, if I am not mistaken, these were the first likenesses produced with this kind of illumination. However, a number of facts, not pertaining to the subject presently considered, were observed in the course of the experiments which, had they been immediately published, might have materially hastened important scientific developments which have taken place since. To dwell on these and other experimental results obtained at that time, more extensively at the first opportunity, is one of my good resolutions for the coming year. A calamity unfortunately, interrupted my labors for a short period, but as soon as I was able I took up again the thread of the investigation, which was not only interesting in connection with the principal object in view, but was also useful in many other respects. So, for instance, in making observations as to the efficiency or any peculiarity of the vacuum tubes, the photographic plate was found to be an excellent means of comparison, note being taken of the distance and time of exposure, character of the phosphorescent body, degree of rarefaction and other such particulars of the moment.

A rather curious feature in the photographs obtained with tubes of moderate illuminating power, as a few candles, was that the lights and shadows came out remarkably strong, as when very short exposures are made by flashlight, but the outlines were not sharp and practically no detail was visible. By producing tubes of much greater candlepower, a notable improvement in this respect was effected, and this advance prompted me to further efforts in this direction, which finally resulted in the production of a tube of an illuminating power of equal to that of hundreds, and even thousands, of ordinary vacuum tubes. What is more, I believe that I am far from having attained the limit in the amount of light producible, and believe that this method of illumination will be eventually employed for lighthouse purposes. This probably will be considered the oddest and most unlooked-for development of the vacuum tube.

Simultaneously with this progress a corresponding improvement was made in the efficiency of the light produced. A few words on this point might not be amiss, considering that a popular and erroneous opinion still exists in regard to the power consumed by vacuum tubes lighted by ordinary means. So deeply rooted is this opinion which, I will frankly confess, I myself shared for a long time, that, shortly after my own first efforts, Sir David Solomons and Messrs. Pike & Harris undertook to introduce in England such tubes on a large scale in competition with the incandescent system of lighting. The enterprise, which was commented on in the technical periodicals, was commendable enough, but it was not difficult to foretell its fate; for although the high-frequency currents obtained from the alternator yielded better economical results than interrupted currents, and although they were obtained in a convenient and fairly economical manner, still the efficiency of the whole system was necessarily too small for competition with incandescent lamps. The reason for the great power consumption, which may often be as much as 10 times that taking place in incandescent lamps for an equivalent amount of light, are not far to seek. A vacuum tube, particularly if it be very large, offers an immense radiating surface, and is capable of giving off a great amount of energy without rising perceptibly in temperature. What still increases the dissipation of energy is the high temperature of the rarefied gas. Generally it is supposed that the particles are not brought to a high temperature, but a calculation from the amount of matter contained in the tube, leads to results which would seem to indicate that, of all the means at disposal for bringing a small amount of matter to a high temperature, the vacuum tube is the most effective. This observation may lead to valuable uses of such tubes in astronomical researches, and a line of experiment to this end was suggested to me recently by Dr. Geo. E. Hale, of the Yerkes Observatory. As compared with these disadvantages the incandescent lamp, crude and inefficient as it undoubtedly is, possesses vastly superior features. These difficulties have been recognized by me early, and my efforts during the past few years have been directed towards overcoming these defects and have finally resulted in material advances, so that I find it possible to obtain from a tube of a volume not much greater than that of a bulb of an incandescent lamp, about the same amount of light produced by the latter, without the tube becoming overheated, which is sure to take place under ordinary conditions. Both of these improvements, the increase of candle-power as well as degree of efficiency, have been achieved by gradual perfection of the means of producing economically harmonical electrical vibrations of extreme rapidity. The fundamental principle involved is now well known, and it only remains to describe the features of the system in detail, a duty with which I expect to be able to comply soon, this being another one of my good resolutions.

The purpose of the present communication is chiefly to give an idea in how far the object here aimed at was obtained. The photographs shown were taken by a tube having a radiating surface of about two hundred square inches. The frequency of the oscillations, which were obtained from an Edison direct-current supply circuit, I estimated to be about two million a second. The illuminating power of the tube approximated about one thousand candles, and the exposures ranged from two to five seconds, the distance of the object being four to five feet from the tube. It might be asked why, with so high an illuminating power, the exposures should not be instantaneous. I would not undertake to satisfactorily answer this question, which was put to me recently by a scientific man, whose visit to my laboratory I still vividly recollect. Likenesses can, of course, be obtained with instantaneous exposures, but it has been found preferable to expose longer and at a greater distance from the tube. The results so far obtained would make it appear that this kind of light will be of great value in photography, not only because the artist will be able to exactly adjust the conditions in every experiment so as to secure the best result, which is impossible with ordinary light. He will thus be made entirely independent of daylight, and will be able to carry on his work at any hour, night or day. It might also be of value to the painter, though its use for such purposes I still consider problematical.

I anticipate that much detail will naturally be lost in the reproductions through the half-tone process and press work, however good, but I hope that enough will be shown to demonstrate the advantageous features of this light in photography and its practical usefulness in this art.

In conclusion, I wish to thank Mr. R. L. Newman for kindly consenting to the use of his photograph.

NIKOLA TESLA New York, Jan. 3.

New York Journal
Feb. 6, 1898


NIKOLA Tesla Writes of the Interesting Possibilities of This New and Successful Device of Animal Trainers in Europe.

To the Editor of the Journal:

It seems to me that there are interesting possibilities in the training of animals by electricity. Of course, it’s rather out of my province, but the idea of the electrical subjugator appears feasible when one knows the power of electricity and the instinctive fear that brutes have of the unknown. And the electrical method seems more humane than those I believe are in use – the whip, red hot irons, and drugs, which are likely to do permanent injury, while the physical effects of an electric shock are soon gone, only the moral ones remaining.

The subjugator referred to will do the work, but I think an apparatus could be designed that would be less dangerous to the man. I do not desire to be understood as giving the matter deep thought, but believe that if, instead of the armored backpad, the trainer used a wand, with two prongs at one end, better results would follow. This wand would be connected with the supply cables and could be applied to any part of the animal’s body at will. Its operation would be precisely the same as the subjugator here illustrated, the two prongs supplying the positive and negative poles of contact found in the flattened wires. With this wand an animal could be simply shocked, stunned or killed, as required.

To cure animals of jumping at men in cages, a screen of stout but flexible wire could be stretched between the trainer and his subject, the wires to be alternately positive and negative, and connected through the regulator with the dynamo. After a couple of springs which would hurl him half insensible back into his corner, the taste for unexpected jumps would leave the brute.

Prague, Jan. 22.

Science has come to aid the lion tamer in subduing the wild beast. The red hot iron will, in future, be cast aside as unnecessary and out of date. Live wires, surcharged with electricity that baffle the lion’s fiercest assaults, and burn and maim him badly have taken the place of the lash and scorching iron. A lion tamer of Austria, Louis Koemmenich, has been the first to call in the assistance of the lightning to subdue wild beasts.

Koemmenich has invented what he calls the electrical subjugator. This is a shield of electric wires that fasten on the back of the lion tamer and are connected with a dynamo by a wire coil of sufficient length to allow Koemmenich to move around the cage.

In his hand he will carry a charged metal ball on an insulated handle, to be used as the red hot iron was in former days.

The dynamo is operated by an assistant outside of the cage.

Should a lion show a disposition to leap on Koemmenich, he invites attack by deliberately turning his back to the lion and apparently encouraging the onslaught.

When the beast springs his paws come in contact with the electric shield, and he receives a shock of 1,500 volts from the dynamo.

The operator can, if necessary, increase the voltage so as to shock the animal to death.

Thus far the device has worked like magic. One dose of lightning is sufficient for the average lion. Whips and even hot irons they have dared, but no animal has yet troubled Koemmenich after receiving into its body 1,500 volts from the electric subjugator. Whenever Koemmenich enters the cage after an encounter with a lion that has run against the electrical subjugator, he will cower away into a corner of the cage, and never need any further punishment.

New York Journal
Nov. 13, 1898


by Nikola Tesla

Yesterday Nikola Tesla gave to the Sunday Journal exclusively the news of his latest invention – a submarine torpedo boat. He has perfected his device after observing the defects of the torpedo boats in the recent war, and noting the fatalities of submarine boats invented up to date. His submarine boat will carry no lives to risk, but can be directed at a distance of miles from on shore or from the deck of a war ship. The power to do this will be the electric vibrations of the air used in wireless telegraphy. By this means a whole flotilla of submarine destroyers can be turned against a hostile fleet, and perhaps destroy it, without the enemy knowing how they were attacked. This seems almost incredible until the great magician of electricity explains his wonderful invention, point by point, in the following statement.

“I am now prepared to announce through the Journal my invention of a submarine torpedo boat that I am confident will be the greatest weapon of the navy from this time on.

“The almost utter uselessness of the present kind of torpedo boat has been conclusively demonstrated in the recent war. Neither the courage and skill of the Americans nor the desperate extremities of the Spaniards were able to bring the torpedo boats into successful action. These frail craft, of which so much was expected, simply made an easy target for land batteries and rapid-fire guns of opposing war ships.

“The submarine boats, on the other hand, which have up to this time been built to carry torpedoes have proved death traps for men and were consequently ineffective. The submarine boat, or, more properly speaking, the submarine destroyer, which I have invented is as compact as the torpedo itself. In fact, it is simply an enlarged torpedo shell, thirty-six and a half feet long, loaded with other torpedoes to discharge. Like a torpedo, also, it has its own propelling device. But here the likeness stops. The ordinary torpedo, once launched, plunges head on blindly and no known power can turn it one way or another. It hits or misses, according to the trueness with which it is aimed at its launching.

“But my submarine boat, loaded with its torpedoes, can start out from a protected bay or be dropped over a ship’s side, make its devious way below the surface, through dangerous channels of mine beds, into protected harbors and attack a fleet at anchor, or go out to sea and circle about, watching for its prey, then dart upon it at a favorable moment, rush up to within a hundred feet if need be, discharge its deadly weapon and return to the hand that sent it. Yet through all these wonderful evolutions it will be under the absolute and instant control of a distant human hand on a far-off headland, or on a war ship whose hull is below the horizon and invisible to the enemy.

“I am aware that this sounds almost incredible and I have refrained from making this invention public till I had worked out every practical detail of it. In my laboratory I now have such a model, and my plans and description at the Patent Office at Washington show the full specifications of it.

“As to the mechanism which is to be stored in this submarine shell: The first and most essential thing is a motor, with storage battery to drive the propeller. Then there are smaller motors and batteries to operate the steering gear, on the same principle that an ordinary vessel is now steered by steam or electricity. Besides these there are still other storage batteries and motors to feed electric signal lights. But in order that the weight of the machinery shall not be too great to destroy the buoyancy or make the boat go too deep in the water compressed air motors will also be used to perform certain functions, such as to fill and empty the water tanks which raise the boat to the surface or sink it to any required depth. Pneumatic air or motors will also fire the torpedoes and pump out the water that may leak in at any time.

“This submarine destroyer will be equipped with six 14-foot Whitehead torpedoes. These will be arranged vertically in two rows in the bow. As one torpedo falls into position and is discharged by pneumatic force, another torpedo, by the force of gravity, falls into the position of the first one, the others above being held up by automatic arms. They can be fired as rapidly as a self-cocking revolver is emptied or at intervals of minutes or hours. The discharge takes place through a single tube, projecting straight ahead in the bow. The small amount of water which leaks through each time is caught by drain pipes and a compressed air pump instantly expels it. As each torpedo is expelled a buoyancy regulator will open the sea cocks and let enough water in the ballast tanks to make the buoyancy uniform and keep the boat at the same distance beneath the surface.

“This submarine destroyer will carry a charge of torpedoes greater than that of the largest destroyers now in use. Those vessels of five hundred tons each which cost the Government $500,000, carry but three or four torpedoes, while this simple submarine destroyer, which can be built for $48,000 to $50,000 or less, will carry six torpedoes. It will have, also, the incalculable advantage of being absolutely invisible to an enemy, and have no human lives to risk or steam boilers to blow up and destroy itself.

“All that is necessary to make this submarine boat subject to perfect control at any distance is to properly wire it, just like a modern house is wired so that a button here rings a bell, a lever there turns on the lights, a hidden wire somewhere else sets off a burglar alarm and a thermal device give a fire alarm.

“The only difference in the case of the submarine boat is in the delicacy of the instruments employed. To the propelling device, the steering gear, the signal apparatus and the mechanism for firing the torpedoes are attached little instruments which are attuned to a certain electro-magnetic synchronism.

“Then there is a similar set of synchronistic instruments all connected to the little switchboard, and placed either on shore or on an ordinary war ship. By moving the lever on the switchboard I can give the proper impulse to the submarine boat to go ahead, to reverse, throw the helm to port or starboard, rise, sink, discharge her torpedoes or return.

“It might be thought that some great power would be necessary to be projected across miles of distance and operate on the far-off boat. The power is all stored in the submarine boat itself – in its storage batteries and compressed air. All that is needed to affect the synchronistic instruments is a set of high alternating currents, which can be produced by my oscillator attached to any ordinary dynamo situated on shore or on a war ship.

“How such an apparently complicated mechanism can be operated and controlled at a distance of miles is no mystery. It is as simple as the messenger call to be found in almost any office. This is a little metal box with a lever on the outside. By moving the crank to a certain point it gives vibrating sounds and springs back into position, and its momentary buzzing calls a messenger. But move this same crank a third further around the dial and it buzzes still longer, and pretty soon a policeman appears, summoned by its mysterious call. Again, move the crank this time to the farthest limit of the circle and scarcely has its more prolonged hum of recoil sounded when the city fire apparatus dashes up to your place at its call.

“Now, my device for controlling the motion of a distant submarine boat is exactly similar. Only I need no connecting wires between my switchboard and the distant submarine boat, for I make use of the now well-known principle of wireless telegraphy. As I move this little lever to points which I have marked on a circular dial I cause a different number of vibrations each time. In this case two waves go forth at each half turn of the lever and affect different parts of the distant destroyer’s machinery.

“How such submarine destroyers should actually be used in war I leave for naval tacticians to determine. But it seems to me that they could best be operated by taking a number on board a large fast auxiliary cruiser like the St. Louis or St. Paul, launch them, several at a time, like life boats, and direct their movements from a switch board placed in the forward fighting top.

“In order that the director of the submarine destroyer may know its exact position at every movement, two masts, at bow and stern, will project up just above the water, too minute to be seen or hit by an enemy’s guns by day, and by night they will carry hooded lights.

“The lookout placed in the fighting top could detect a hostile ship off on the horizon while the auxiliary cruiser’s big hull is still invisible to the enemy. Starting these little destroyers out under direction of a man with a telescope, they could attack and destroy a whole armada – destroy it utterly -in an hour, and the enemy never have a sight of their antagonists or know what power destroyed them. A big auxiliary cruiser, used to carry these submarine destroyers, could also carry a cargo of torpedoes sufficient to conduct a long campaign and go half way around the world.

“She could carry the gun cotton and other explosives needed to load the torpedoes in safe magazines below the water line, and do away with much of the danger of transporting loaded torpedoes. When necessary for use the war heads could be loaded, fitted to the torpedoes, and the submarine destroyers fully equipped.

“A high, projecting headland overlooking a harbor and the sea would also be a good point on which to establish a station and have the destroyers laid up at docks below ready to start.

“That is the whole story of my latest invention. It is simple enough, you say. Of course it is, because I have worked all my life to make each one of the details so simple that it will work as easily as the electric ticker in a stock broker’s office.

Electrical Engineer – N. Y.
Nov. 24, 1898, p. 514

New York, Nov. 18, 1898

46 & 48 East Houston St.

Editor of The Electrical Engineer, 120 Liberty St., New York City:

Sir – By publishing in your columns of Nov. 17 my recent contribution to the Electro-Therapeutic Society you have finally succeeded – after many vain attempts made during a number of years – in causing me a serious injury. It has cost me great pains to write that paper, and I have expected to see it appear among other dignified contributions of its kind, and I confess, the wound is deep. But you will have no opportunity for inflicting a similar one, as I propose to take better care of my papers in the future. In what manner you have secured this one in advance of other electrical periodicals who had an equal right to the same, rests with the secretary of the society to explain.

Your editorial comment would not concern me in the least, were it not my duty to take note of it. On more than one occasion you have offended me, but in my qualities both as Christian and philosopher I have always forgiven you and only pitied you for your errors. This time, though, your offence is graver than the previous ones, for you have dared to cast a shadow on my honor.

No doubt you must have in your possession, from the illustrious men whom you quote, tangible proofs in support of your statement reflecting on my honesty. Being a bearer of great honors from a number of American universities, it is my duty, in view of the slur thus cast upon them, to exact from you that in your next issue you produce these, together with this letter, which in justice to myself, I am forwarding to other electrical journals. In the absence of such proofs, I require that, together with the preceding, you publish instead a complete and humble apology for your insulting remark which reflects on me as well as on those who honor me.

On this condition I will again forgive you; but I would advise you to limit yourself in your future attacks to statements for which you are not liable to be punished by law.


Electrical Review – N. Y.
Nov, 30, 1898, pp. 344, 345


TO THE EDITOR OF THE SUN – Sir: Had it not been for other urgent duties, I would before this have acknowledged your highly appreciative editorial of November 13. Such earnest comments and the frequent evidences of the highest appreciation of my labors by men who are the recognized leaders of this day in scientific speculation, discovery and invention are a powerful stimulus, and I am thankful for them. There is nothing that gives me so much strength and courage as the feeling that those who are competent to judge have faith in me.

Permit me on this occasion to make a few statements which will define my position in the various fields of investigation you have touched upon.

I can not but gratefully acknowledge my indebtedness to earlier workers, as Dr. Hertz and Dr. Lodge, in my efforts to produce a practical and economical lighting system on the lines which I first disclosed in a lecture at Columbia College in 1891. There exists a popular error in regard to this light, inasmuch as it is believed that it can be obtained without generation of heat. The enthusiasm of Dr. Lodge is probably responsible for this error, which I have pointed out early by showing the impossibility of reaching a high vibration without going through the lower or fundamental tones. On purely theoretical grounds such a result is think- able, but it would imply a device for starting the vibrations of unattainable qual-ities, inasmuch as it would have to be entirely devoid of inertia and other prop-erties of matter. Though I have conceptions in this regard, I dismiss for the present this proposition as being impossible. We can not produce light without
heat, but we can surely produce a more efficient light than that obtained in the incandescent lamp, which, though a beautiful invention, is sadly lacking in the feature of efficiency. As the first step toward this realization, I have found it necessary to invent some method for transforming economically the ordinary currents as furnished from the lighting circuits into electrical vibrations of great rapid-ity. This was a difficult problem, and it was only recently that I was able to announce its practical and thoroughly satisfactory solution. But this was not the only requirement in a system of this kind. It was necessary also to increase the intensity of the light, which at first was very feeble. In this direction, too, I met with complete success, so that at present I am producing a thoroughly service- able and economical light of any desired intensity. I do not mean to say that
this system will revolutionize those in use at present, which have resulted from the co-operation of many able men. I am only sure that it will have its fields of use-fulness.

As to the idea of rendering the energy of the sun available for industrial purposes, it fascinated me early but I must admit it was only long after I discovered the rotating magnetic field that it took a firm hold upon my mind. In assailing the problem I found two possible ways of solving it. Either power was to be developed on the spot by converting the energy of the sun’s radiations or the energy of vast reservoirs was to be transmitted economically to any distance. Though there were other possible sources of economical power, only the two solutions mentioned offer the ideal feature of power being obtained without any consumption of material. After long thought I finally arrived at two solutions, but on the first of these, namely, that referring to the development of power in any locality from the sun’s radiations, I can not dwell at present. The system of power transmission without wires, in the form in which I have described it recently, originated in this manner. Starting from two facts that the earth was a conductor insulated in space, and that a body can not be charged without causing an equivalent displacement of electricity in the earth, I undertook to construct a machine suited for creating as large a displacement as possible of the earth’s electricity.

This machine was simply to charge and discharge in rapid succession a body insulated in space, thus altering periodically the amount of electricity in the earth, and consequently the pressure all over its surface. It was nothing but what in mechanics is a pump, forcing water from a large reservoir into a small one and back again. Primarily I contemplated only the sending of messages to great distances in this manner, and I described the scheme in detail, pointing out on that occasion the importance of ascertaining certain electrical conditions of the earth. The attractive feature of this plan was that the intensity of the signals should diminish very little with the distance, and, in fact, should not diminish at all, if it were not for certain losses occurring, chiefly in the atmosphere. As all my previous ideas, this one, too, received the treatment of Marsyas, but it forms, nevertheless, the basis of what is now known as “wireless telegraphy.” This statement will bear rigorous examination, but it is not made with the intent of detracting from the merit of others. On the contrary, it is with great pleasure that I acknowledge the early work of Dr. Lodge, the brilliant experiments of Marconi, and of a later experimenter in this line, Dr. Slaby, of Berlin. Now, this idea I extended to a system of power transmission, and I submitted it to Helmholtz on the occasion of his visit to this country. He unhesitatingly said that power could certainly be transmitted in this manner, but he doubted that I could ever produce an apparatus capable of creating the high pressures of a number of million volts, which were required to attack the problem with any chance of success, and that I could overcome the difficulties of insulation. Impossible as this problem seemed at first, I was fortunate to master it in a comparatively short time, and it was in perfecting this apparatus that I came to a turning point in the development of this idea. I, namely, at once observed that the air, which is a perfect insulator for currents produced by ordinary apparatus, was easily traversed by currents furnished by my improved machine, giving a tension of something like 2,500,000 volts. A further investigation in this direction led to another valuable fact; namely, that the conductivity of the air for these currents increased very rapidly with its degree of rarefaction, and at once the transmission of energy through the upper strata of air, which, without such results as I have obtained, would be nothing more than a dream, became easily realizable. This appears all the more certain, as I found it quite practicable to transmit, under conditions such as exist in heights well explored, electrical energy in large amounts. I have thus overcome all the chief obstacles which originally stood in the way, and the success of my system now rests merely on engineering skill.

Referring to my latest invention, I wish to bring out a point which has been overlooked. I arrived, as has been stated, at the idea through entirely abstract speculations on the human organism, which I conceived to be a self-propelling machine, the motions of which are governed by impressions received through the eye. Endeavoring to construct a mechanical model resembling in its essential, material features the human body, I was led to combine a controlling device, or organ sensitive to certain waves, with a body provided with propelling and directing mechanism, and the rest naturally followed. Originally the idea interested me only from the scientific point of view, but soon I saw that I had made a departure which sooner or later must produce a profound change in things and conditions presently existing. I hope this change will be for the good only, for, if it were otherwise, I wish that I had never made the invention. The future may or may not bear out my present convictions, but I can not refrain from saying that it is difficult for me to see at present how, with such a principle brought to great perfection, as it undoubtedly will be in the course of time, guns can maintain themselves as weapons. We shall be able, by availing ourselves of this advance, to send a projectile at much greater distance, it will not be limited in any way by weight or amount of explosive charge, we shall be able to submerge it at command, to arrest it in its flight, and call it back, and to send it out again and explode it at will, and, more than this, it will never make a miss, since all chance in this regard, if hitting the object of attack were at all required, is eliminated. But the chief feature of such a weapon is still to be told; namely, it may be made to respond only to a certain note or tune, it may be endowed with selective power. Directly such an arm is produced, it becomes almost impossible to meet it with a corresponding development. It is this feature, perhaps, more than in its power of destruction, that its tendency to arrest the development of arms and to stop warfare will reside. With renewed thanks, I remain,

Very truly, yours,


New York, November 19.

Electrical Review – N . Y .
March 29, 1899, pp. 195-197, 204.


To the Editor of Electrical Review:

Since the unfortunate accident of four years ago, which crippled and delayed my labors in a number of lines so seriously, I have had but little time to devote to the fulfillment of a duty which, next to that of turning his best efforts to diligent inquiry in the fields he has chosen, is the most important to a scientific man; namely, that of giving an exact record of the results obtained. I realize with sorrow every day that, despite of all pains taken to this end, I am gaining but very slowly on the material accumulated. Ideas come through a happy inspiration, apparently without much exertion, but it is the working out of the many harassing details and putting into a presentable form which consumes time and energy. It was impossible to abandon research in new directions, in which I have felt myself irresistibly drawn, and it was equally impossible to do full justice to the work partially completed, and I can only hope to gradually retrieve my losses by the only expedient available, which is to redouble the zeal. It is not the best plan to follow, I confess, and is in radical opposition to the kindly advice given to me to the effect that I intended to live 200 years by sleeping most of the time! It may also show that it is not this mode of life which is responsible for the delay in the commercial introduction of my system of vacuum tube lighting, as has been asserted by some people who have found a singular satisfaction in dwelling extensively in their columns on my proposed glass house on Long Island, which was to cover acres of ground, and which was to be built for the purpose of catching the sun’s rays; on my claims of the discoveries of Roentgen; on my invention enabling me to move and explode torpedo boats by will power, and on my efforts to annihilate the entire British navy. It is to be hoped that the limit of patience of the readers has been finally reached.

At that time, still painfully remembered, my energies were taken up principally by some mechanical problems of great importance, and the few observations in electricity which I was fortunate to make came like ever so many refreshing berries found on the road by a weary wanderer. The journey is not finished yet, and the wanderer is well-nigh exhausted. He longs for more sweet berries, and anxiously asks, “Did any one pass this road before?”

It was chiefly in three directors that electrical investigation was attractive and promising: There were the excessive electrical pressures of millions of volts, which opened up wonderful possibilities if producible in practical ways; there were currents of many hundreds of thousands of amperes, which appealed to the imagination by their astonishing effects, and, most interesting and inviting of all, there were the powerful electrical vibrations with their mysterious actions at a distance. What better work could one do than inventing methods and devising means for enabling scientific men to push investigation far out into these practically unknown regions? This work was difficult and tedious and involved a certain amount of material sacrifice, but promised a higher reward if successfully accomplished – the gratitude of those many who exercise their gifts in different directions and are compelled to rely on the expert for providing them with implements suitable for their special purpose. Who can estimate how much science has been advanced by the beautiful instruments of measure which Lord Kelvin has given us? Unfortunately, in many of the new fields such instruments are yet to be invented. Still more unfortunately, informations seems to be more needful than instruments, if one is to judge from statements frequently made in technical periodicals on a variety of subjects. An experimenter, for instance, measures the current through a make-and-break device, and, finding it small, he infers that the conversion is economical. Another suggests to determine the efficiency of conversion through such a device by the calorimetric method. Now, as a matter of fact, if there was such a contrivance, absolutely perfect in its action, which would behave as I have explained on another occasion, and change the resistance of a gap from zero to infinity without any loss in the gap itself, which separates the terminals, it still might happen that 99 per cent of the energy supplied to the circuit would be wasted in radiations, useless for the purpose contemplated. The calorimetric method would in this, or generally in any other instance, in which the disturbances produced are very sudden, entirely fail in giving an approximation as to the energy dissipated in the circuit, for the simple reason that the friction encountered by a wave in its passage through a medium, which determines the amount of heat generated, is no measure whatever of the energy of the wave. Thus, certain well understood cases excepted, the only method at present available in such estimates is to take account of the energy consumed by the source of supply. This remark alone will show that the economical conversion of currents by make and break devices is a much more difficult problem than it appears to those who have studied it superficially. Not only must the devices used in the transformation possess certain characteristics, but the entire circuit must be properly designed. One can not help admiring the confidence and self-possession of experimenters, who put forth carelessly such views and who, with but a few days’, not to say hours’, experience with a device, apparently unmindful of the responsibility of such a step, and advance their imperfect results and opinions hastily formed. The sparks may be long and brilliant, the display interesting to witness, and the audience may be delighted, but one must doubt the value of such demonstrations. There is so little novelty in them, that one might easily perform a practical joke on the lecturer by describing in advance all his drawings, apparatus, experiments and theories, this placing him in an awful predicament. Though such a course would be naturally impolite, it might be found justified and excused by the circumstances, for premature expressions of opinion and demonstrations of this kind are responsible for much evil, one of these being the erroneous idea which they create in scientific circles as to the importance of an advance made. It grieves one to observed that, for example, such great work as that of Professor Dewar, which he turns out with clock regularity, is scarcely commented upon in the technical columns, whereas a worthless trap for interrupting currents, which usually consumes nine-tenths of the energy, and is, besides, useless for other reasons, and just suitable for the amusement of small boys, who are beginning their electrical experience with Leclanche batteries and $1.50 induction coils, is hailed as an important scientific discovery. An agreeable contrast is afforded by those who patiently investigate, contented to lose the credit for advances made rather than to present them to the world in an imperfect state, who form their opinions conscientiously, after a long and careful study, and have little to correct afterward.

The importance of the task of providing proper implements for research in these fields once recognized, it became the question in what line the efforts to this end would be likely to be most profitable. A little thought showed that it was in investigating high electrical pressures, for these were needed in most instances. More than a passing thought was given to static electricity, with the experiments of Franklin as starting point. Various forms of generators of static electricity were experimented upon, and some new ones designed, to which I hope to revert some time, as they present some features of interest. The most valuable outcome of these experiments was a method of conversion which I have described, and which enables the operation of any kind of devices of low tension from such a high-pressure source with perfect ease and safety, no matter how high the tension. Soon, however, it was recognized that with the above object in view generators of steady pressure were entirely impractical, quite apart from their incidental limitations. It was exactly as if one attempted to drive piles into the ground by the application of continuous pressure. This would require cumbersome and powerful machinery, and would be very inconvenient. An incomparably better way of developing high pressure is by delivering violent blows as with a hammer. In such a case the motion of the hammer being suddenly arrested pressure is developed on the point of impact, which is all the greater the smaller the displacement caused, and if there were material absolutely rigid, incompressible and inelastic, an infinite pressure might thus be developed by a small blow. Hence one is forcibly driven to the use of a transformer or induction coil as means for producing great electrical pressures. The first difficulty encountered was that of insulation, and it might be interesting and useful to show, chiefly to those who are less familiar with this special subject, how by gradual improvement, from the ordinary inductorium capable of furnishing currents of very moderate electro-motive force, an apparatus was finally evolved in which there is practically no limit as to the pressure obtainable.

Selecting first the closed core transformer, one easily recognizes that it is unsuitable for the attainment of the object in view for obvious reasons. Nevertheless, by adopting the plan illustrated in the first diagram of Fig. 2, I succeeded in obtaining nearly 200,000 volts, and I think that more than twice this tension is practicable by means of such an arrangement, which involves the use of independent and entirely insulated sources of supplying the primaries, as will be understood from an inspection of the diagram without further explanation. The evident limitations of the closed-core type in the way of insulation, rate of change and frequency of the current impulses, led to the adoption of an open-core type, as a matter of course, and the various diagrams of the figure referred to illustrate the modifications as they were gradually made in the manner of insulating and winding of the coils. In diagram 2 the old, primitive method of insulation is indicated. In diagram 3 the succeeding layers are insulated by material increasing in thickness gradually from one end to the other, being thickest on the place of greatest difference of potential. The thickness is easily calculated beforehand, and is such that all the insulation is as nearly as possible uniformly strained. As it was impracticable to pile up many layers in the manner illustrated in diagram 3, naturally the modification illustrated in diagram 4 was made, which led to a further improvement, indicated in diagram 5. It was recognized, however, that there was no advantage in winding many coils, and that all that was needed were two secondary coils joined in the middle, as illustrated in diagram 6, the secondaries being, of course, wound as shown in diagram 3. Next, in order to increase the output of the coil and gain other advantages, the relative customary position of the primary and secondary windings was reversed and the coil as shown in diagram 7 produced, the two secondary coils being joined on their outer, instead of on their inner ends, as before. This construction was considerably better than that illustrated in diagram 6, as the primary and secondary coils were placed in closer inductive relation. But when with this coil the tension had been pushed far enough, it was found that the iron core limited the spark length, and then two insulated cores, one in each coil, were resorted to, which were finally discarded, and so the coil shown in diagram 8 resulted, which I have described on several occasions and which, of all other constructions, permits the obtainment of the highest possible tension with a two-terminal coil in a given space.

But even in this perfected type it was not possible to go beyond a certain potential difference, and a further investigation led to a new type, which I have called a single terminal coil, and which is illustrated in diagram 9 and is now well known. In this coil the adjustment is so made that the secondary is nearly equal to the quarter of the wave length, the highest potential being, under these conditions, produced on the free terminal. Subsequently I extended such adjustment also to the coils in diagram 8, improving the same materially.

During these efforts I fortunately discovered the important part which air played in the breaking down of the insulation, and by adopting proper methods for the exclusion of gaseous matter, I was able to increase the electro-motive force to more than 10 times the value without breaking down the secondary. I have described this method since, which I am using in the manufacture of coils and condensers, and without which it would be entirely impossible to reach any such results as I have obtained. The industrial world has profited by the recognition of the action of the air, for it has helped to extend power transmission to greater distances than heretofore practicable. It has also been useful in determining the limits of the electro-motive forces with ordinary apparatus used in power transmission, but I see that no attempt is yet made to overcome the streamers by a suitable construction of the cables, as I have indicated, and thus make higher electro-motive forces available.

Further experimentation with the original single-terminal coil, before referred to, finally led step by step to the adoption of a coil of large dimensions, which, in two typical forms, is illustrated in diagrams 10 and 11. With such a coil I found that there was practically no limit to the tension available, and it is by its means that I discovered the most important of all facts arrived at in the course of my investigation in these fields. One of these was that atmospheric air, though ordinarily a perfect insulator, conducted freely the currents of immense electromotive force producible by such coils and suitable accessories. So great is the conductivity of the air, that the discharge issuing from a single terminal behaves as if the atmosphere were rarefied. Another fact is that this conductivity increases very rapidly with rarefaction of the atmosphere and augmentation of the electrical pressure, to such an extent that at barometric pressures which permit of no transit of ordinary currents, those generated by such a coil pass with great freedom through the air as through a copper wire. Following up these promising revelations I demonstrated conclusively by experiments that great amounts of electrical energy can be transmitted to any distance through upper air strata which are easily accessible, and since this truth has been recognized every fiber has been strained to realize such a transmission on a large scale. These two observations explain clearly the silent discharges noted frequently in dense air strata, but three or four miles above the Earth’s surface. One more equally important fact I may mention, which was simultaneously observed. The discharges of such a coil, when of an electro-motive force of a few millions of volts, excite powerful affinities in the atmospheric nitrogen, causing it to combine readily with the oxygen and other elements, particularly in the presence of aqueous vapor. So energetic are these actions and so strangely do such powerful discharges behave, that I have often experienced a fear that the atmosphere might be ignited, a terrible possibility, which Sir William Crookes, with his piercing intellect, has already considered. Who knows but such a calamity is possible? And who can tell with certitude that periodical cessations of organic life on the globe might not be caused by ignition of the air and destruction of its life-sustaining qualities, accidentally or as a consequence of some accumulative change? A lump of coal will lie for centuries unaffected in contact with oxygen, but the combustion once started, the process continues as long as there are elements to combine.

While improving the construction of the transformers, every effort was made to perfect the apparatus for generating the currents. The objective point from the outset was to obtain the greatest possible rate of variation. High-frequency alternators were first used, but their limitations were soon apparent. I then turned again and again to make and break devices, chiefly with the object of using them in connection with a novel form of transformer, which I have previously described, and which is now well known and understood. In its original form, as I first showed it, it is illustrated in diagram 12, which need not be dwelt upon, beyond saying that one of the characteristic features of such an instrument is the energizing of the primary of the induction coil by the rapidly succeeding discharges of a condenser. In a more recent type, specially adapted for ordinary supply circuits, which I have described and shown before several scientific societies, the transformer comprises, as indicated in diagram 13, three coils, there being, in addition to the primary and secondary coils, one which receives the currents from the supply circuit, and is designated the charging coil. Preferably tee latter is not in inductive relation with the former. On a number of occasions I have described high-frequency apparatus embodying this beautiful method, which has already been of great value to science in my hands as well as in those of others. But a defect, to which I called attention early, still confronted me. It lay in the make and break devices which performed the function of charging and discharging the condenser. Many of such devices, based on a variety of principles, formed the subject of experiments carried on with the aim of doing away with this imperfection. To cite one of these, the current from the source of supply was passed through a minute column of conducting liquid maintained in a variety of ways, and in this simple manner rapidly succeeding impulses were obtained. Incidentally, some useful results were secured with these contrivances, as, for example, the generation of currents of differing phase and the production of rotating fields moving with constant velocity; but, interesting as these simple devices were, they naturally precluded the possibility of economical conversion. Their study, however, was useful as a means of recognizing the requirements of such make and break apparatus, and, finally, led to forms based on scientific and economical principles. A number of these were recently described in technical periodicals and, as stated on a former occasion, they fulfill their difficult duty surprisingly well and make it possible to obtain currents of very high frequency from ordinary supply circuits with great economy. These novel contrivances lend themselves well also to the uses of the ordinary induction coil, and I have employed them with equal success in a form of Plante’s rheostatic machine and for many other useful purposes. Thus, after a continuous effort extending through a number of years, I have the supreme satisfaction of having carried this hard and important task to a satisfactory end.

The annexed photographs will serve to convey an idea of what can be done with these perfected implements. Referring to Fig. 1, illustrative of the high rate of change obtained in the current, a vacuum bulb of about 12 inches in diameter is held in front of a coil of four turns of specially constructed heavy cable, through which a condenser is discharging, and, although at a distance of several inches from the coil, the gas in the bulb is brought to intense incandescence, the light emitted being fully equal to 1,500 candles. Such a powerfully energized coil, when the frequency, as in this instance, is measured in millions per second, shows little repellent action, but when the frequency of the impulses is low, closed conductors, as washers of conducting material, are thrown off with a force of a magnitude which can be only explained on the assumption that the currents have maximum values of many hundred thousand amperes.

The remaining photographs will be understood from the titles, which are made explicit for this purpose. I hope to have in the near future an opportunity for describing more of such experiments, and dwelling in detail on the apparatus used. For the present I am compelled, for want of time, to merely state that the vibrations used in most of them were from 400,000 to 800,000 per second.

In conclusion I wish to apologize for the frequent appearance of my likeness in these photographs, which is distasteful to me, but was unavoidable. Most of the advances indicated, and a number of others, have resulted from the application of the beautiful principle upon which the operation of this apparatus is based. Scientific men have honored me by identifying it with my name, and I have earnestly endeavored to show myself worthier of this great distinction by devoting to it much of my energies. No desire for material advantages has animated me in all this work, though I hope, for the sake of the continuance of my labors, that these will soon follow, naturally, as a compensation for valuable services rendered to science and industry. To the scientific experts, who are familiar, in theory and experiment, with electrical vibrations, the results here shown will, I believe, speak in eloquent language. But those readers to whom they are naturally less intelligible will ask: What are they good for, and what do they or have they demonstrated? To them it may be said that they have shown and proved among many other things: That ordinary currents can be transformed with high economy into electrical vibrations of any pitch, which are needed in many novel arts; they have shown that electrical energy in great amounts can be efficiently and safely transmitted without the use of wires to any point of the globe, however distant; they have furnished proof that the movements and operation of bodies and machinery carried by the same can be controlled from a great distance without any tangible connection whatever and with absolute precision; they have proved the practicability of a system of signaling without wires, not with the imperfect appliances as before attempted, which can not be tuned and are rendered useless by the play of a small induction coil, but by means of apparatus producing powerful oscillations and circuits in exact synchronism, with which it is impossible to interfere; they have shown that atmospheric nitrogen can be readily combined and valuable products manufactured, merely by the application of cheap water power, and that light, diffusive like that of the sun, can be produced with an economy greater than obtainable in the usual ways and with lamps that never consume.

N. Tesla.

New York, March 26, 1899

New York Sun
Jan. 30, 1901


Capacity of Electrical Conductors is Variable.

Not Constant, and Formulas Will Have to Be Rewritten – Capacity Varies With Absolute Height Above Sea Level, Relative Height From Earth and Distance From the Sun.

Nikola Tesla announced yesterday another new discovery in electricity. This time it is a new law and by reason of it, Mr. Tesla asserts, a large part of technical literature will have to be rewritten. Ever since anything has been known about electricity, scientific men have taken for granted that the capacity of an electrical conductor is constant. When Tesla was experimenting in Colorado he found out that this capacity is not constant – but variable. Then he determined to find out the law governing this phenomenon. He did so, and all this he explained to The Sun yesterday. Here is what he said:

“Since many years scientific men engaged in the study of physics and electrical research have taken it for granted that certain quantities, entering continuously in their estimates and calculations, are fixed and unalterable. The exact determination of these quantities being of particular importance in electrical vibrations, which are engrossing more and more the attention of experimenters all over the world, it seems to be important to acquaint others with some of my observations, which have finally led me to the results now attracting universal attention. These observations, with which I have long been familiar, show that some of the quantities referred to are variable and that, owing to this, a large portion of the technical literature is defective. I shall endeavor to convey the knowledge of the facts I have discovered in plain language, devoid as much as possible of technicalities.

“It is well known that an electric circuit compacts itself like a spring with a weight attached to it. Such a spring vibrates at a definite rate, which is determined by two quantities, the pliability of the spring and the mass of the weight. Similarly an electric circuit vibrates, and its vibration, too, is dependent on two quantities, designated as electrostatic capacity and inductance. The capacity of the electric circuit corresponds to the pliability of the spring and the inductance to the mass of the weight.

“Exactly as mechanics and engineers have taken it for granted that the pliability of the spring remains the same, no matter how it be placed or used, so electricians and physicists have assumed that the electrostatic capacity of a conducting body, say of a metallic sphere, which is frequently used in experiments, remains a fixed and unalterable quantity, and many scientific results of the greatest importance are dependent on this assumption. Now, I have discovered that this capacity is not fixed and unalterable at all. On the contrary, it is susceptible to great changes, so that under certain conditions it may amount to many times its theoretical value, or may eventually be smaller. Inasmuch as every electrical conductor, besides possessing an inductance, has also a certain amount of capacity, owing to the variations of the latter, the inductance, too, is seemingly modified by the same causes that tend to modify the capacity. These facts I discovered some time before I gave a technical description of my system of energy transmission and telegraphy without wires, which, I believe, became first known through my Belgian and British patents.

“In this system, I then explained, that, in estimating the wave-length of the electrical vibration in the transmitting and receiving circuits, due regard must be had to the velocity with which the vibration is propagated through each of the circuits, this velocity being given by the product of the wave-length and the number of vibrations per second. The rate of vibration being, however, as before stated, dependent on the capacity and inductance in each case, I obtained discordant values.

Continuing the investigation of this astonishing phenomenon I observed that the capacity varied with the elevation of the conducting surface above the ground, and I soon ascertained the law of this variation. The capacity increased as the conducting surface was elevated, in open space, from one-half to three-quarters of 1 per cent per foot of elevation. In buildings, however, or near large structures, this increase often amounted to 50 per cent per foot of elevation, and this alone will show to what extent many of the scientific experiments recorded in technical literature are erroneous. In determining the length of the coils or conductors such as I employ in my system of wireless telegraphy, for instance, the rule which I have given is, in view of the above, important to observe.

“Far more interesting, however, for men of science is the fact I observed later, that the capacity undergoes an annual variation with a maximum in summer, and a minimum in winter. In Colorado, where I continued with improved methods of investigations begun in New York, and where I found the rate of increase slightly greater, I furthermore observed that there was a diurnal variation with a maximum during the night. Further, I found that sunlight causes a slight increase in capacity. The moon also produces an effect, but I do not attribute it to its light.

“The importance of these observations will be better appreciated when it is stated that owing to these changes of a quantity supposed to be constant an electrical circuit does not vibrate at a uniform rate, but its rate is modified in accordance with the modifications of the capacity. Thus a circuit vibrates a little slower at an elevation than when at a lower level. An oscillating system, as used in telegraphy without wires, vibrates a little quicker when the ship gets into the harbor than when on open sea. Such a circuit oscillates quicker in the winter than in the summer, though it be at the same temperature, and a trifle quicker at night than in daytime, particularly if the sun is shining.

“Taking together the results of my investigations I find that this variation of the capacity and consequently of the vibration period is evidently dependent, first, on the absolute height above sea level, though in a smaller degree; second, on the relative height of the conducting surface or capacity with respect to the bodies surrounding it; third, on the distance of the earth from the sun, and fourth, on the relative change of the circuit with respect to the sun, caused by the diurnal rotation of the earth. These facts may be of particular interest to meteorologists and astronomers, inasmuch as practical methods of inquiry may result from these observations, which may be useful in their respective fields. It is probable that we shall perfect instruments for indicating the altitude of a place by means of a circuit, properly constructed and arranged, and I have thought of a number of other uses to which this principle may be put.

“It was in the course of investigations of this kind in Colorado that I first noted certain variations in electrical systems arranged in peculiar ways. These variations I first discovered by calculating over the results I had previously noted, and it was only subsequently that I actually perceived them. It will thus be clear that some who have ventured to attribute the phenomena I have observed to ordinary atmospheric disturbances have made a hasty conclusion.”

Scientific American
Feb. 2, 1901, p. 67. TESLA’S WIRELESS LIGHT.

Nikola Tesla has given to The New York Sun an authorized statement concerning his new experiments on the production of light without the aid of wires. Mr. Tesla says:

“This light is the result of continuous efforts since my early experimental demonstrations before scientific societies here and abroad. In order to make it suitable for commercial use, I had to overcome great difficulties. One of these was to produce from ordinary currents of supply electrical oscillations of enormous rapidity in a simple and economical manner. This, I am glad to say, I have now accomplished, and the results show that with this new form of light a higher economy is practicable than with the present illuminants. The light offers, besides, many specific advantages, not the least of which is found in its hygienic properties. It is, I believe, the closest approach to daylight which has yet been reached from any artificial source.

“The lamps are glass tubes which may be bent in any ornamental way. I most generally use a rectangular spiral, containing about twenty to twenty-five feet of tubing making some twelve to fourteen convolutions. The total illuminating surface of a lamp is from 300 to 400 square inches. The ends of the spiral tube are covered with a metallic coating, and provided with hooks for hanging the lamp on the terminals of the source of oscillations. The tube contains gases rarefied to a certain degree, determined in the course of long experimentation as being conductive to the best results.

“The process of light production is, according to my views, as follows: The street current is passed through a machine which is an electrical oscillator of peculiar construction and transforms the supply current, be it direct or alternating, into electrical oscillations of very high frequency. These oscillations, coming to the metallically-coated ends of the glass tube, produce in the interior corresponding electrical oscillations, which set the molecules and atoms of the enclosed rarefied gases into violent commotion, causing them to vibrate at enormous rates and emit those radiations which we know as light. The gases are not rendered incandescent in the ordinary sense, for if it were so, they would be hot, like an incandescent filament. As a matter of fact, there is very little heat noticeable, which speaks well for the economy of the light, since all heat would be loss.

“This high economy results chiefly from three causes: First, from the high rate of the electrical oscillations; second, from the fact that the entire light-giving body, being a highly attenuated gas, is exposed and can throw out its radiations unimpeded, and, third, because of the smallness of the particles composing the light-giving body, in consequence of which they can be quickly thrown into a high rate of vibration, so that comparatively little energy is lost in the lower or heat vibrations. An important practical advantage is that the lamps need not be renewed like the ordinary ones, as there is nothing in them to consume. Some of these lamps I have had for years, and they are now in just as good a condition as they ever were. The illuminating power of each of these lamps is, measured by the photometric method, about fifty candle power, but I can make them of any power desired, up to that of several arc lights. It is a remarkable feature of the light that during the day it can scarcely be seen, whereas at night the whole room is brilliantly illuminated. When the eye becomes used to the light of these tubes, an ordinary incandescent lamp or gas burner produces a violent pain in the eye when it is turned on, showing in a striking manner to what a degree these concentrated sources of light which we now use are detrimental to the eye.

“I have found that in almost all its actions the light produces the same effects as sunlight, and this makes me hopeful that its introduction into dwellings will have the effect of improving, in a measure now impossible to estimate, the hygienic conditions. Since sunlight is a very powerful curative agent, and since this light makes it possible to have sunlight, so to speak, of any desired intensity, day and night in our homes, it stands to reason that the development of germs will be checked and many diseases, as consumption, for instance, successfully combated by continually exposing the patients to the rays of these lamps. I have ascertained unmistakably that the light produces a soothing action on the nerves, which I attribute to the effect which it has upon the retina of the eye. It also improves vision just exactly as the sunlight, and it ozonizes slightly the atmosphere. These effects can be regulated at will. For instance, in hospitals, where such a light is of paramount importance, lamps may be designed which will produce just that quality of ozone which the physician may desire for the purification of the atmosphere, or if necessary, the ozone production can be stopped altogether.

“The lamps are very cheap to manufacture, and by the fact that they need not be exchanged like ordinary lamps or burners they are rendered still less expensive. The chief consideration is, of course, in commercial introduction, the energy consumption. While I am not yet prepared to give exact figures, I can say that, given a certain quantity of electrical energy from the mains, I can produce more light than can be produced by the ordinary methods. In introducing this system of lighting my transformer, or oscillator, will be usually located at some convenient place in the basement, and from there the transformed currents will be led as usual through the building. The lamps can be run with one wire alone, as I have shown in my early demonstrations, and in some cases I can dispense entirely with the wires. I hope that ultimately we shall get to this ideal form of illumination, and that we shall have in our rooms lamps which will be set aglow no matter where they are placed, just as an object is heated by heat rays emanating from a stove. The lamps will then be handled like kerosene lamps, with this difference, however, that the energy will be conveyed through space. The ultimate perfection of apparatus for the production of electrical oscillations will probably bring us to this great realization, and then we shall finally have the light without heat or ‘cold’ light. I have no difficulty now to illuminate the room with such wireless lamps, but a number of improvements must be made yet before it can be generally introduced.”

Collier’s Weekly
Feb. 9, 1901, pp. 4-5.


by Nikola Tesla

The idea of communicating with the inhabitants of other worlds is an old one. But for ages it has been regarded merely as a poet’s dream, forever unrealizable. And yet, with the invention and perfection of the telescope and the ever-widening knowledge of the heavens, its hold upon our imagination has been increased, and the scientific achievements during the latter part of the nineteenth century, together with the development of the tendency toward the nature ideal of Goethe, have intensified it to such a degree that it seems as if it were destined to become the dominating idea of the century that has just begun. The desire to know something of our neighbors in the immense depths of space does not spring from idle curiosity nor from thirst for knowledge, but from a deeper cause, and it is a feeling firmly rooted in the heart of every human being capable of thinking at all.

Whence, then, does it come? Who knows? Who can assign limits to the subtlety of nature’s influences? Perhaps, if we could clearly perceive all the intricate mechanism of the glorious spectacle that is continually unfolding before us, and could, also, trace this desire to its distant origin, we might find it in the sorrowful vibrations of the earth which began when it parted from its celestial parent.

But in this age of reason it is not astonishing to find persons who scoff at the very thought of effecting communication with a planet. First of all, the argument is made that there is only a small probability of other planets being inhabited at all. This argument has never appealed to me. In the solar system, there seem to be only two planets – Venus and Mars – capable of sustaining life such as ours; but this does not mean that there might not be on all of them some other forms of life. Chemical processes may be maintained without the aid of oxygen, and it is still a question whether chemical processes are absolutely necessary for the sustenance of organized beings. My idea is that the development of life must lead to forms of existence that will be possible without nourishment and which will not be shackled by consequent limitations. Why should a living being not be able to obtain all the energy it needs for the performance of its life-functions from the environment, instead of through consumption of food, and transforming, by a complicated process, the energy of chemical combinations into life-sustaining energy?

If there were such beings on one of the planets we should know next to nothing about them. Nor is it necessary to go so far in our assumptions, for we can readily conceive that, in the same degree as the atmosphere diminishes in density, moisture disappears and the planet freezes up, organic life might also undergo corresponding modifications, leading finally to forms which, according to our present ideas of life, are impossible. I will readily admit, of course, that if there should be a sudden catastrophe of any kind all life process might be arrested; but if the changes, no matter how great, should be gradual, and occupied ages, so that the ultimate results could be intelligently foreseen, I cannot but think that reasoning beings would still find means of existence. They would adapt themselves to their constantly changing environment. So I think it quite possible that in a frozen planet, such as our moon is supposed to be, intelligent beings may still dwell, in its interior, if not on its surface.


Then it is contended that it is beyond human power and ingenuity to convey signals to the almost inconceivable distances of fifty million or one hundred million miles. This might have been a valid argument formerly. It is not so now. Most of those who are enthusiastic upon the subject of interplanetary communication have reposed their faith in the light-ray as the best possible medium of such communication. True, waves of light, owing to their immense rapidity of succession, can penetrate space more readily than waves less rapid, but a simple consideration will show that by their means an exchange of signals between this earth and its companions in the solar system is, at least now, impossible. By way of illustration, let us suppose that a square mile of the earth’s surface – the smallest area that might possibly be within reach of the best telescopic vision of other world’s – were covered with incandescent lamps, packed closely together so as to form, when illuminated, a continuous sheet of light. It would require not less than one hundred million horse power to light this area of lamps, and this is many times the amount of motive power now in the service of man throughout the world.

But with the novel means, proposed by myself, I can readily demonstrate that, with an expenditure not exceeding two thousand horse-power, signals can be transmitted to a planet such as Mars with as much exactness and certitude as we now send messages by wire from New York to Philadelphia. These means are the result of long continued experiment and gradual improvement.

Some ten years ago, I recognized the fact that to convey electric currents to a distance it was not at all necessary to employ a return wire, but that any amount of energy might be transmitted by using a single wire. I illustrated this principle by numerous experiments, which, at that time, excited considerable attention among scientific men.

This being practically demonstrated, my next step was to use the earth itself as the medium for conducting the currents, thus dispensing with wires and all other artificial conductors. So I was led to the development of a system of energy transmission and of telegraphy without the use of wires, which I described in 1893. The difficulties I encountered at first in the transmission of currents through the earth were very great. At that time I had at hand only ordinary apparatus, which I found to be ineffective, and I concentrated my attention immediately upon perfecting machines for this special purpose. This work consumed a number of years, but I finally vanquished all difficulties and succeeded in producing a machine which, to explain its operation in plain language, resembled a pump in its action, drawing electricity from the earth and driving it back into the same at an enormous rate, thus creating ripples or disturbances which, spreading through the earth as through a wire, could be detected at great distances by carefully attuned receiving circuits. In this manner I was able to transmit to a distance, not only feeble effects for purposes of signalling, but considerable amounts of energy, and later discoveries I made convince me that I shall ultimately succeed in conveying power without wires, for industrial purposes, with high economy, and to any distance, however great.


To develop these inventions further, I went to Colorado in 1899, where I continued my investigations along these and other lines, one of which in particular I now consider of even greater importance than the transmission of power without wires. I constructed a laboratory in the neighborhood of Pike’s Peak. The conditions in the pure air of the Colorado mountains proved extremely favorable for my experiments, and the results were most gratifying to me. I found that I could not only accomplish more work, physically and mentally, than I could in New York, but that electrical effects and changes were more readily and distinctly perceived. A few years ago it was virtually impossible to produce electrical sparks twenty or thirty feet long; but I produced some more than one hundred feet in length, and this without difficulty. The rates of electrical movement involved in strong induction apparatus had measured but a few hundred horse-power, and I produced electrical movements of rates of one hundred and ten thousand horse-power. Prior to this, only insignificant electrical pressures were obtained, while I have reached fifty million volts.

The accompanying illustrations, with their descriptive titles, taken from an article I wrote for the “Century Magazine,” may serve to convey an idea of the results I obtained in the directions indicated.

Many persons in my own profession have wondered at them and have asked what I am trying to do. But the time is not far away now when the practical results of my labors will be placed before the world and their influence felt everywhere. One of the immediate consequences will be the transmission of messages without wires, over sea or land, to an immense distance. I have already demonstrated, by crucial tests, the practicability of signalling by my system from one to any other point of the globe, no matter how remote, and I shall soon convert the disbelievers.

I have every reason for congratulating myself that throughout these experiments, many of which were exceedingly delicate and hazardous, neither myself nor any of my assistants received an injury. When working with these powerful electrical oscillations the most extraordinary phenomena take place at times. Owing to some interference of the oscillations, veritable balls of fire are apt to leap out to a great distance, and if any one were within or near their path, he would be instantly destroyed. A machine such as I have used could easily kill, in an instant, three hundred thousand persons. I observed that the strain upon my assistants was telling, and some of them could not endure the extreme tension of the nerves. But these perils are now entirely overcome, and the operation of such apparatus, however powerful, involves no risk whatever.

As I was improving my machines for the production of intense electrical actions, I was also perfecting the means for observing feeble effects. One of the most interesting results, and also one of great practical importance, was the development of certain contrivances for indicating at a distance of many hundred miles an approaching storm, its direction, speed and distance travelled. These appliances are likely to be valuable in future meteorological observations and surveying, and will lend themselves particularly to many naval uses.

It was in carrying on this work that for the first time I discovered those mysterious effects which have elicited such unusual interest. I had perfected the apparatus referred to so far that from my laboratory in the Colorado mountains I could feel the pulse of the globe, as it were, noting every electrical change that occurred within a radius of eleven hundred miles.


I can never forget the first sensations I experienced when it dawned upon me that I had observed something possibly of incalculable consequences to mankind. I felt as though I were present at the birth of a new knowledge or the revelation of a great truth. Even now, at times, I can vividly recall the incident, and see my apparatus as though it were actually before me. My first observations positively terrified me, as there was present in them something mysterious, not to say supernatural, and I was alone in my laboratory at night; but at that time the idea of these disturbances being intelligently controlled signals did not yet present itself to me.

The changes I noted were taking place periodically, and with such a clear suggestion of number and order that they were not traceable to any cause then known to me. I was familiar, of course, with such electrical disturbances as are produced by the sun, Aurora Borealis and earth currents, and I was as sure as I could be of any fact that these variations were due to none of these causes. The nature of my experiments precluded the possibility of the changes being produced by atmospheric disturbances, as has been rashly asserted by some. It was some time afterward when the thought flashed upon my mind that the disturbances I had observed might be due to an intelligent control. Although I could not decipher their meaning, it was impossible for me to think of them as having been entirely accidental. The feeling is constantly growing on me that I had been the first to hear the greeting of one planet to another. A purpose was behind these electrical signals; and it was with this conviction that I announced to the Red Cross Society, when it asked me to indicate one of the great possible achievements of the next hundred years, that it would probably be the confirmation and interpretation of this planetary challenge to us.

Since my return to New York more urgent work has consumed all my attention; but I have never ceased to think of those experiences and of the observations made in Colorado. I am constantly endeavoring to improve and perfect my apparatus, and just as soon as practicable I shall again take up the thread of my investigations at the point where I have been forced to lay it down for a time.


At the present stage of progress, there would be no insurmountable obstacle in constructing a machine capable of conveying a message to Mars, nor would there be any great difficulty in recording signals transmitted to us by the inhabitants of that planet, if they be skilled electricians. Communication once established, even in the simplest way, as by a mere interchange of numbers, the progress toward more intelligible communication would be rapid. Absolute certitude as to the receipt and interchange of messages would be reached as soon as we could respond with the number “four,” say, in reply to the signal “one, two, three.” The Martians, or the inhabitants of whatever planet had signalled to us, would understand at once that we had caught their message across the gulf of space and had sent back a response. To convey a knowledge of form by such means is, while very difficult, not impossible, and I have already found a way of doing it.

What a tremendous stir this would make in the world! How soon will it come? For that it will some time be accomplished must be clear to every thoughtful being.

Something, at least, science has gained. But I hope that it will also be demonstrated soon that in my experiments in the West I was not merely beholding a vision, but had caught sight of a great and profound truth.

Philadelphia – North American
May 18, 1902


Lord Kelvin’s article containing the astonishing prophecy that windmills will furnish the future power of the world was written expressly for the Sunday North American during his recent visit to the United States. It is the only article that came from his pen while he was in America. Emanating from a less famous source the prediction that one day the earth will return to its most primitive motive power would be received with little less than ridicule. In view of the fact that Lord Kelvin is beyond question the greatest scientific authority, as is shown by the reverence with which he was received by American savants, his opinion in this matter is of the utmost importance to the world at large.

In discussing the subject with a reporter for the Sunday North American, Lord Kelvin asserted that from the present outlook the windmill will be the only source of motive power to which man will be able to turn once the supply of coal is exhausted. Storehouses of power, such as Niagara Falls, he said, appear, upon their face, to be enormous, but when the tremendous amount of energy required to move the wheels of the earth’s energy is considered, they sink into insignificance. Once the coal fields are stripped of their precious contents, he stated, efforts will doubtless be made to raise at least a partial supply of fuel upon the farms of the land. This is not so unreasonable as at first it seems. The farmers in Iowa and Nebraska, where coal is scarce and very expensive, are even now burning their excess of corn as fuel. The supply from this source, will, as Lord Kelvin points out, necessarily be very limited, as years go by and the population of the world increases. The supply of air, however, is inexhaustible and Lord Kelvin believes man will be obliged to have recourse to it as a motive power, just as he did hundreds of years ago.

Commenting on the motive power of the future, Nikola Tesla, the electrical scientist, agrees with Lord Kelvin that the world must one day fall back upon the force of the wind. Thomas A. Edison, who in addition to being the world’s greatest electrician is a man of varied achievements, admits that one day the fuel supply will be exhausted. This day he believes will be exceedingly remote, estimating that the South American forests alone could provide fuel, in wood, for fifty thousand years. When the last bit of fuel has been consumed, the wind may be utilized in generating electricity which will turn a good portion of the world’s machinery. It is suggested by Professor Langley, in speaking of Lord Kelvin’s prophecy, that the sun may one day share with the wind in furnishing power, if indeed it does not do all the work. Admiral Bradford, who has been busy for the past few years locating sites for United States coaling stations at the four corners of the earth, takes the most optimistic view of all. He believes that when the coal supply is exhausted some other means of furnishing motive power equally good will be found to take its place, and that the world will not be seriously affected.


To predict that the world’s industrial progress will one day be halted and then rolled back in primitive methods is not a very daring prophecy when the conditions are studied closely.

Coal is king of the industrial world. The king’s reign is limited. Sooner or later, it has been estimated that the world’s supply of coal will have been exhausted. The commission appointed to inquire into the all-important matter in Great

Britain has even said that a few hundred years at the outside will see the last basket of coal taken from the mines of England. In other quarters the supply is rapidly diminishing.

The enormous amount of coal required to run our great ocean steamships, our leviathans of the deep, and the innumerable factories of our cities is making such inroads upon the available store that nature cannot forever supply the demand. When all the coal of the earth is used, what then?

Perplexed humanity confronted with the possibility of its industrial machinery being stopped for want of power, will be forced to turn from earth to air. In the world there is to be found a force that has stood man in good stead from time immemorial. Long before the days of the steam engine or the ocean liners, ships were wafted from shore to shore by means of the force that lurks in the air. The time will come, unless man’s ingenuity devises some means of replacing the exhausted coal supply with a fuel that will be equally efficacious – when the swift steaming greyhounds of the oceans will be dry-docked and their vitals torn out. Then the lightened ships will be fitted with the masts and sails of the old sailing days, and once more the seas will be dotted with vessels propelled by the method that is at present in decline. The day upon which the last shovelful of coal is taken from the bowels of the earth will mark the passing of the magnificent battleship, the swift cruiser and the torpedo boat. The navies of the nations will perish in a day for want of life-giving fire in the furnace rooms. In their place will arise white-winged fleets depending alone on their sailing power, as in the days of Nelson; the question of which ocean liner can cut down time of the passage from New York to Liverpool will no longer interest voyagers, for the trip will depend, as of old, on the favorable winds and the sailing capacity of the ship.

On land the effect of the exhaustion of the coal supply will be even more marked than on sea. Every building could be supplied with its own windmill, to use the motive power that wanders where it listeth on its roof top to turn wheels that will lift its elevators, generate electricity for its machinery, pump its water supply and do all that coal now makes possible in the machine room; sails on our factories, sails on our mills and in our shipyards to catch the slightest breath that blows and turn it into a means of moving the wheels of progress; wind power utilized everywhere as the servant of man, free for every one, working silently as a great force while the world sleeps. Possibly the exhaustion of the coal supply of the earth may turn out to be something of a blessing when it is considered how difficult and dangerous it is to wrest from the ground the hidden resources of nature for use as fuel, and how natural and easy it is to make the power of wind do the work now done by coal.

Then, in the great land changes of the coalless age I see vast fields of vegetation planted especially to serve as fuel. Each agriculturist will have his own reservation where the family fuel will be grown; a new industry will be born – the cultivation of fuel.

Water power will be largely useful, but the power to be derived from this source is not very great. Niagara is a vast force to look at, but measured in the horsepower it is not so tremendous. The tides cannot furnish any power worth speaking of; firewood must do much more.


He Established the Doctrine of the Conservation of Energy. His Siphon Recorder Made Transatlantic Telegraphy Feasible-Business Man and Able Politician

It is not exaggeration to say that no living scientist ranks higher than Lord Kelvin. His fame is world-wide. The savants of all countries recognize in him the greatest of physicists, and the rare combinations of an abstruse thinker and a practical inventor.

Merely to mention a few of the directions in which he has achieved success is to show the extraordinary activity that has marked his career.

His fame as an electrician almost equals his eminence as a physicist. He is an unequaled mathematician, the inventor of a hundred valuable devices which are in daily use, a great teacher, an expounder of popular science, and a clever and successful politician.

What he has done in any one of these lines would suffice to make a proud reputation, and in addition he has found time to be a keen business man and to build up a considerable fortune.

And all this is the achievement of a man who started poor and had his own way to make practically without assistance.

Kelvin, then plain William Thomson, first became noted for the part he played in the invention and installation of the Atlantic cable.

This was in 1857. The greatest obstacle which had to be overcome before the system could be established was a certain sluggishness in the flow of the current which had the effect of making the message almost inaudible. Thomson promptly remedied this defect, and then set himself to the discovery of an instrument for taking down cable messages.

The result was the “siphon recorder”, which is still in use throughout the world in all ocean telegraphy. With it as many as 130 words per minute have been sent, where two or three were formerly the rule.

Along the same line Kelvin also invented numerous instruments for measuring both strong and feeble currents. For his work in connection with the cable Thomson was knighted. Twenty-five years later, in 1892, he was elevated to the peerage as Lord Kelvin.

Even before his great success with the cable the young inventor had been recognized as a scientist of exceptional attainments. It is a fact, indeed, that he began doing great things when little more than a boy.

His chair as professor of natural philosophy at Glasgow he won when only 22 years of age. The attention of English scholars had been drawn to him at that time because of his mathematical prowess – he won ten prizes and wrote many important papers while at Cambridge.

For fifty-three years he held his chair at Glasgow, and the passing of the half century was signalized by a celebration in which the scientists of practically the whole world took part. It was a great spontaneous demonstration entirely without precedent or parallel.

The distinctive feature of Lord Kelvin’s activities, the keynote to his career, so to speak, is his power of combining the abstract with the practical. Although a profound thinker and scholar, to whom the most advanced lines of human research are as simple as the alphabet to the ordinary layman, he has been the inventor of a legion of the little things that men need in their everyday lives. Not only has he dealt in theory, but he has done things.

His various measuring and testing devices have kept a firm of instrument makers in Glasgow busy for years.

Among these, probably the best known is his magnetic compass for the use of mariners. This was such a radical improvement on any existing instrument that it displaces the others, and still remains a factor of incalculable value in securing the safety of ocean travel.

Another important invention much used on ships is a deep-sea sounding apparatus which permits what previously had never even been dreamed of, the taking of soundings in 100 fathoms from a ship running 16 knots.

Many of Lord Kelvin’s researches have dealt with the doctrine of the conservation of energy. He was, indeed, one of the six or eight men, who, living in different countries and working in entire independence of each other, simultaneously established this important theory. Another subject which he has made a specialty, is the age of the earth, and his controversies with the extravagant claims of the geologists are renowned.

The present theory of the ether, the light-bearing, electricity-carrying something which fills all space, has been in large part his creation, and his famous idea that what we call matter is merely vortices or whirlpools in this ether may be regarded as one of the most far-reaching speculations in modern physics. The mechanical principle by which we obtain liquid air – that a compressed gas expanding freely, without doing work, cools slightly more than the theory demands – is a discovery Kelvin made in conjunction with his friend Joule.

So great an authority has Lord Kelvin become on all matters dealing with either speculative or practical science that in England he is called upon to pass on the practicability of almost every important scientific proposition that comes up for discussion.

His laboratory contains the best equipment in the world for making tests. The first storage batteries imported into England from France were sent to him for a verdict. When American capitalists conceived the plan of utilizing the power of Niagara Falls for commercial purposes and of transmitting it for distances, it was Lord Kelvin whom they placed at the head of the committee of experts which passed on the original plans.

Lord Kelvin’s achievements as physicist, electrician and inventor would have made at least three eminent reputations. His marvelous works have not only been recognized by Great Britain, but nearly all the nations of Europe have showered their honors upon him. He is a member of the Prussian Order pour le Merite, grand officer of the Legion of Honor of France, commander of the Order of King Leopold of Belgium, order of the first class of Sacred Treasure of Japan, foreign associate of the Berlin Academy of Science, president of the Royal Society of England and many others. Fifteen universities have conferred on him the honor of their degrees.



by Nikola Tesla

The power of the wind has been overlooked. Some day it will be forcibly brought to the position it deserves through the need of a substitute for the present method of generating power. Given a good breeze, I have estimated that there is as much as half a horse-power to every square foot of area exposed. Imagine what energy is left unused with all this force at hand.

The contrivance that has been at the disposal of mankind from all time, the windmill, is now seen in the rural districts only. The popular mind cannot grasp the power there is in the wind. Many a deluded inventor has spent years of his life in endeavoring to harness the tides, and some have even proposed to compress air by tide or wave power for supplying energy, never understanding the signs of the old windmill on the hill as it sorrowfully waves its arms about and bids them stop.

The fact is that the wave or tide motor would have but small chance of competing commercially with the windmill, which is by far the better machine, allowing a much greater amount of energy to be obtained in a simpler way.

Wind power has been in all times of inestimable value to man, if for nothing else than for enabling him to cross the seas, and it is even now a very important factor in transportation. But there are limitations in this simple method of utilizing the sun’s energy. The machines are large for a given output and the power is intermittent, thus necessitating a storage of energy and increasing the cost of the plant. But there is no question as to its usefulness as a substitute for the energy derived from fuel, and the fact that this power is literally as free as air makes it a wonderful factor in the future of the world of industry.

Apart from the views expressed by Lord Kelvin regarding the future, when the coal supply shall have been exhausted, there is need of more attention being paid to it in the present day.

The man who cannot afford to have a furnace in his house may have a windmill on the roof. In this labor-saving age it is astonishing that farmers are the only citizens who call the wind their friend. Dwellers in cities toil up and down stairs hauling and carrying while above them is a good-natured giant who can do all this work for them if they will but force him into service. Why wait for the coal supply of the earth to be exhausted before enlisting the aid of this vast aerial force?

The power to run elevators, pump water to roof tanks, cool houses in the summer and heat them in the winter is above us, at any one’s beck and call.

A little ingenuity will enable any householder to harness the wind and leave it to do the work that he has considered part of the curse of Adam.


by Professor S. P. Langley, of the Smithsonian Institution.

Lord Kelvin’s suggestion of the return to wind as a motive power is pregnant of suggestion.

The problem is one that must engage the scientific mind until pressure of circumstances forces a solution. But, at the same time, while I do not wish to place myself in the position of flatly contradicting so eminent a thinker and student as his Lordship, I feel that his solution of the problem is but partial at the best, and that the true substitute for coal will be found in another direction.

The power that exists in the sun’s rays will, in all probability, be the force that will drive the wheels of factories and propel ships and railroads. The tremendous energy that is stored in these rays has long been known to science and several practical attempts have been made to utilize them. As I have already pointed out in my work, “The New Economy,” the idea is beginning to pass into the region of the practical utility, and is the form of the latest achievement of Mr. Ericsson’s ever young genius is ready for actual work on an economical scale. His new solar engine, which there is every reason to believe is more efficient than Mouchot’s would probably be capable of economical use for pumping water in the desert regions of our own country. We must consider the growing demand for power in the world and the fact that its stock of coal, though vast, is strictly limited in the sense that when it is gone we can get absolutely no more. The sun has been making a little every day for millions of years – so little and for so long that it is as though time had daily dripped a single penny into the bank for our credit for untold ages, until an enormous fund had been thus slowly accumulated in our favor. We are now drawing on this fund like a prodigal who thinks his means endless, but the day will come when our check will no longer be honored, and what shall we do then?

The exhaustion of some of the coal beds is an affair of the immediate future, by comparison with the vast period of time we have been speaking of. The English coal beds, it is asserted, will be quite used up in about three hundred years more.

Three hundred years ago the sun, looking down on the England of our forefathers, saw a fair land of green woods and quiet waters, a land unvexed with noisier machinery than the spinning wheel. Because of the coal which has been dug from its soil, he sees it now soot-blackened, furrowed with railway cuttings, covered with noisy manufactories, filled with grimy operatives, while the island shakes with the throb of coal-driven engines, and its once quiet waters are churned by the wheels of steamships. Many generations of men have passed to make the England of Elizabeth into the England of King Edward, but what a brief moment this is compared with the vast lapse of ages during which the coal was being stored! What a moment in the life of the “all-beholding sun”, who in a few hundred years may send his beams through rents in the ivy-grown walls of deserted factories, upon silent engines brown with rust, while the mill hand has gone to other lands, the rivers are clean again, the harbors show only white sails and England’s “black country” is green once more! To America, too, such a time may come, though at a more distant date.

Future ages may see the seat of empire transferred to regions of the earth now barren and desolated under intense solar heat – countries which, for that very cause, will not improbably become the seat of mechanical and hence of political power.

Whoever finds the way to make industrially useful, the vast sun power now wasted on the deserts of North Africa or the shores of the Red Sea will effect a greater change in men’s affairs than any conqueror in history has done. He will once more people those waste places with the life that swarmed there in the best days of Carthage and of old Egypt, but under another civilization, where man no longer shall worship the sun as a god, but shall have learned to make it his servant.


by Thomas A. Edison

I cannot altogether agree with Lord Kelvin as to the nearness of time when the fuel supply of the world will be exhausted.

There is wood enough in the forests of South America to supply the world with fuel for 50,000 years. Wood as fuel takes up more space than coal, but it must be remembered that we are constantly economizing on the amount of fuel necessary to do a given amount of work. The quantity of fuel used to run a locomotive is being reduced as the machine is perfected and the engineers learn to make the coal box smaller without reducing the speed of the engine. By the time the coal supply is exhausted it may be possible to burn wood with equally good results.

A windmill is a big cumbersome thing and I cannot think it possible that progressive men will settle down contented to go back to this primitive method of obtaining power. I have a windmill on my own property, but I never thought it amounted to much, except for pumping water. Wind power, as every schoolboy knows, can be used for generating electricity, but the horsepower thus obtained would not be adequate to the demands of this bustling age.

Additional energy could be obtained by ships at sea from the motion of the vessel being utilized as a generative agent. While the ship moves through the water, propelled by the force of the wind on its sails, the wave power could be caught up and turned into a means of providing electricity. Then, too, seamen will probably explain that the wind that drives a ship is not the only force to be obtained from the air. There are aerial currents that can be made use of by means of appropriate appliances for catching their force.


by Rear Admiral R. B. Bradford

Rear Admiral R. B. Bradford, chief of the Bureau of Equipment, at Washington, regards the question of the future motive power from an extremely practical standpoint.

“Lord Kelvin,” he said, “is a scientist, a great scientist, but I think he is borrowing trouble. The problem that is before us now is not what the motive power will be two hundred or three hundred years from to-day. It is how best may we conserve the energy we have already stored away in coal. The supply of this article is strictly limited, and its consumption is-increasing in almost arithmetical ratio.

“Unless some force is discovered to replace it, we will soon be at the end of our resources. But it is also true that unless something is discovered to take the place of coal and steam, we shall be compelled to fall back in the end upon the two great forces of nature – the sun’s rays and the wind. Both of these can be utilized to generate power, but the trouble with both is that they are variable.

“Power cannot, of course, be generated from the sun’s rays at night, nor on a cloudy day, and we have periods of calm, when the wind is scarcely perceptible.

“On the other hand, to say what the power of the future will be is pure speculation and prophecy. I am no seventh son of a seventh son, and do not care to go into the prophesying business. But fifty years before the discovery of the steam engine or the discovery of coal, who would have dared to predict the present mechanical development of civilization?

“Something of the same sort may occur during the next fifty years. Some ingenious man may discover a force of nature that will entirely supersede steam. But this I can say, that unless such a discovery is made, the windmills will in time throw their arms to the breeze, and the solar engines will pump our water and drive our factories.”

Electrical World and Engineer
Feb. 6, 1904, p. 256.


We reproduce herewith in slightly reduced facsimile the first page of a four-page circular which has been issued this week by Mr. Nikola Tesla in a large square envelope bearing a large red wax seal with the initials, “N.T.” At the back of the page which we reproduce is given a list of 93 patents issued in this country to Mr. Tesla. The fourth page is blank. The third page has a little vignette of Niagara Falls and is devoted to quotations from various utterances of Mr. Tesla. The first of these is from his lecture delivered in 1893 before the Franklin Institute and the National Electric Light Association, as to transmission of intelligible signals and power to any distance without the use of wires. The second quotation is from his article on the problem of increasing human energy, which appeared in the Century Magazine in June, 1900, dealing with virtually the same subject. The third item quotes from his patents, Nos. 645,576 and 649,621, dealing with the transmission of electrical energy in any quantity to any distance, with transmitting and receiving apparatus movable as in ships or balloons. The circular is an extremely interesting one. It is most sumptuously got up on vellum paper and altogether constitutes a manifesto worthy of the original genius issuing it. It is to be gathered from the circular that Mr. Tesla proposes to enter the field of consulting engineership, in which he already has enjoyed an extensive connection here and abroad.

New York Sun
November 27, 1904

Letter from Nikola Tesla:

“My attention has been called to numerous comments on my letter, published in your issue of November 1, and relating to the electrical equipment of the newly opened catacomb in this city. Some of them are based on erroneous assumptions, which it is necessary for me to correct.

“When I stated that my system was adopted, I did not mean that I originated every electrical appliance in the subway. For instance, the one which that ill-fated electrician was repairing when he was killed, two days after the catacomb was ready for public use, was not invented by me. Nor was that other device on the sidetracked car, which, as will be remembered, caused the burning of two men. I also must deny any connection with that switch or contrivance which was responsible for the premature death of a man immediately afterward, as well as with that other, which cut short the life of his unfortunate successor. None of these funeral devices, I emphatically state, or any of the other which brought on collisions, delays and various troubles and were instrumental in the loss of arms and legs of several victims, are of my invention, nor do they form, in my opinion, necessary appurtenances of an intelligently planned scheme for the propulsion of cars. Referring to these contrivances, it is significant to read in some journals of the 8th inst. that a small firm failed because their bid was too low. This is indicative of keen competition and sharp cutting of prices, and does not seem in keeping with the munificence claimed for the Interborough Company.

“I merely intended to say in my letter that my system of power transmission with three-phase generators and synchronous motor converters was adopted in the subway, the same as on the elevated road. I devised it many years ago for the express purpose of meeting the varied wants of a general electrical distribution of light and power. It has been extensively introduced all over the world because of its great flexibility, and under such conditions of use has been found of great value. But the idea of employing in this great city’s main artery, in a case presenting such rigid requirements, this flexible system, offering innumerable chances for breakdowns, accidents and injuries to life and property, is altogether too absurd to dignify it with any serious comment. Here only my multiphase system, with induction motors and closed coil armatures – apparatus unfailing in its operation and minimizing the dangers of travel – should have been installed. Nothing, not even ignorance, will prevent its ultimate adoption; and the sooner the change is made the better it will be for all concerned. Personally, I have no financial or other interest in the matter, except that as a long resident of this city I would have been glad to see my inventions properly used to the advantage of the community. Under the circumstances I must forego this gratification.

“The consequences of the unpardonable mistake of the Interborough Company are not confined to this first subway or even to this city. We are driven to travel underground. The elevated road is the eighth wonder, as colossal and imposing in the feature of public forbearance as the Pyramid of Cheops in its dimensions. Sooner or later all interurban railways must be transformed into subterranean. This will call for immense investments of capital, and if defective electrical apparatus is generally adopted the damage to life and property will be incalculable, not to speak of inconvenience to the public.

“It seems proper to me to acknowledge on this occasion the painstaking suggestions of some friends of mine, mostly unknown to me, both in the large domain of electrical achievement and in the small sphere of my friendship, to again address the American Institute. It is customary with scientific men to present an original subject only once. I have done so and do not desire to depart from this established precedent. A lecture on the defects of the subway offers great opportunities, but would not be original. In view of certain insinuations I may cite a recently published statement of Mr. C. F. Scott, formerly president of the American Institute: ‘As a matter of history it is the Tesla principle and the Tesla system which have been the directing factors in modern electrical engineering practice.’ There are but a few men whose acknowledgment of my own work I would quote. Mr. Scott is one of them, as the man whose co-operation was most efficient in bringing about the great industrial revolution through these inventions. But the suggestions of my good friends have fallen on fruitful ground, and should it be possible for me to spare time and energy I may ask the city authorities for power to investigate the subway, and make a sworn report to them on all the defects and deficiencies I may discover, in the interest of public welfare.

“A few more words in relation to the signs. With all due respect to general opinion, I entertain quite a different view on that subject. Advertising is a useful art, which is being lifted continually to a higher plane, and will soon be quite respectable. It should not be hampered, but rather encouraged. I would give the Interborough Company every facility for exploiting it, restricting it only in so far as the artistic execution is concerned. A commission of capable men comprising a painter, a sculptor, an architect, a literary man, an engineer and an executive business man might be appointed, to pass upon the merits of the signs submitted for acceptance. I do not see why the public should object to them if they were regulated in this manner. They will further business, make travel less tedious, and help many skillful artisans. The subways are bound to become municipal property, and the city will then derive a revenue from them. What is most important for the safety of life and property, quickness and security of travel, should be first considered. All this depends on the electrical equipment. The engineers have built a good tunnel, and proper apparatus should be installed to match it.

Nikola Tesla

New York, Nov. 26

Manufacturers’ Record
Dec. 29, 1904, p. 583.


NIKOLA Tesla’s View of the Future in Motive Power.

New York, December 27

In view of the great interest which is being taken in the articles published by the Manufacturers’ Record and some of the magazines on the development of new power-producers, through the internal-combustion engine, for use for transportation purposes both by land and sea, the following signed statement, made by Mr. NIKOLA Tesla after a discussion of a new type of auto-bus designed by Mr. Charles A. Lieb, mechanical engineer of the Manhattan Transit Co., will doubtless be read with much general interest:

New York, December 17

Mr. Albert Phenis, Special Correspondent Manufacturers’ Record, New York:

Dear Sir – Replying to your inquiry of yesterday, the application of electricity to the propulsion of automobiles is certainly a rational idea. I am glad to know that Mr. Lieb has undertaken to put it into practice. His long experience with the General Electric Co. and other concerns must have excellently fitted him for the task.

There is no doubt that a highly-successful machine can be produced on these lines. The field is inexhaustible, and this new type of automobile, introducing electricity between the prime mover and the wheels, has, in my opinion, a great future.

I have myself for many years advocated this principle. Your will find in numerous technical publications statements made by me to this effect. In my article in the Century, June, 1900, I said, in dealing with the subject: ‘Steamers and trains are still being propelled by the direct application of steam power to shafts or axles. A much greater percentage of the heat energy of the fuel could be transformed in motive energy by using, in place of the adopted marine engines and locomotives, dynamos driven by specially designed high-pressure steam or gas engines, by utilizing the electricity generated for the propulsion. A gain of 50 to 100 percent, in the effective energy derived from the fuel could be secured in this manner. It is difficult to understand why a fact so plain and obvious is not receiving more attention from engineers.

At first glance it may appear that to generate electricity by an engine and then apply the current to turn a wheel, instead of turning it by means of some mechanical connection with the engine, is a complicated and more or less wasteful process. But it is not so; on the contrary, the use of electricity in this manner secures great practical advantages. It is but a question of time when this idea will be extensively applied to railways and also to ocean liners, though in the latter case the conditions are not quite so favorable. How the railroad companies can persist in using the ordinary locomotive is a mystery. By providing an engine generating electricity and operating with the current motors under the cars a train can be propelled with greater speed and more economically. In France this has already been done by Heilman, and although his machinery was not the best, the results he obtained were creditable and encouraging. I have calculated that a notable gain in speed and economy can also be secured in ocean liners, on which the improvement is particularly desirable for many reasons. It is very likely that in the near future oil will be adopted as fuel, and that will make the new method of propulsion all the more commendable. The electric manufacturing companies will scarcely be able to meet this new demand for generators and motors.

In automobiles practically nothing has been done in this direction, and yet it would seem they offer the greatest opportunities for application of this principle. The question, however, is which motor to employ – the direct-current or my induction motor. The former has certain preferences as regards the starting and regulation, but the commutators and brushes are very objectionable on an automobile. In view of this I would advocate the use of the induction motor as an ideally simple machine which can never get out of order. The conditions are excellent, inasmuch as a very low frequency is practicable and more than three phases can be used. The regulation should offer little difficulty, and once an automobile on this novel plan is produced its advantages will be readily appreciated.

Yours very truly,

N. Tesla.

Electrical World and Engineer
June 24, 1905, p. 1162


The New York Sun of June 16 printed the following letter from Mr. Nikola Tesla:

The flooding of the subway is a calamity apt to repeat itself. As your readers will remember, it did not occur for the first time last Sunday. Water, like fire, will break loose occasionally in spite of precautions. It will never be possible to guard against a casual bursting of a main; for while the conduit can be safely relied upon under normal working conditions, any accidental obstruction to the flow may cause a pressure which no pipe or joint can withstand.

In fact, if we are to place faith in the gloomy forecasts of Commissioner Oakley, who ought to know, such floods may be expected to happen frequently in the future. In view of this it seems timely to call to public attention a danger inherent to the electrical equipment which has been thrust upon the Interborough Company by incompetent advisers.

The subway is bound to be successful, and would be so if the cars were drawn by mules, for it is the ideal means of transportation in crowded cities. But the full measure of success of which it is capable will be attained only when the financiers shall say to the electric companies: “Give us the best, regardless of expense.”

It is to be regretted that this important pioneering enterprise, in other respects ably managed and engineered, should have been treated with such gross neglect in its most vital feature. No opportunity was given to myself, the inventor and patentee of the system adopted in the subway and the elevated roads, for offering some useful suggestion, nor was a single electrician or engineer of the General Electric and Westinghouse companies consulted, the very men who should have been thought of first of all.

Once large sums of money are invested in a defective scheme it is difficult to make a change, however desirable it may be. The movement of new capital is largely determined by previous investment. Even the new roads now planned are likely to be equipped with the same claptrap devices, and so the evil will grow. “Des eben ist der Fluch der boesen Thut, das sie fortzeugend Boeses muss gebaeren.”

The danger to which I refer lies in the possibility of generating an explosive mixture by electrolytic decomposition and thermic dissociation of the water through the direct currents used in the operation of the cars. Such a process might go on for hours and days without being noticed; and with currents of this kind it is scarcely practicable to avoid it altogether.

It will be recalled that an expert found the percentage of free oxygen in the subway appreciably above that which might reasonably have been expected in such a more or less stagnated channel. I have never doubted the correctness of that analysis and have assumed that oxygen is being continuously set free by stray currents passing through the moist ground. The total amperage of the normal working current in the tunnel is very great, and in case of flooding would be sufficient to generate not far from 100 cubic feet of hydrogen per minute. Inasmuch, however, as in railway operation the fuses must be set hard, in order to avoid frequent interruption of the service by their blowing out, in such an emergency the current would be of much greater volume and hydrogen would be more abundantly liberated.

It is a peculiar property of this gas that it is capable of exploding when mixed with a comparatively large volume of air, and any engineer can convince himself by a simple calculation that, say, 100,000 cubic feet of explosive might be formed before the danger is discovered, reported and preventive measures taken. What the effect of such an explosion might be on life and property is not pleasant to contemplate. True, such a disaster is not probable, but the present electrical equipment makes it possible, and this possibility should be, by all means, removed.

The oppressiveness of the tunnel atmosphere is in a large measure due to the heat supplied by the currents, and to the production of nitrous acid in the arcs, which is enhanced by rarefaction of the air through rapid motion. Some provision for ventilation is imperative. But ventilation will not do away with the danger I have pointed out. It can be completely avoided only by discarding the direct current.

I should say that the city authorities, for this if for no other reason, should forbid its use by a proper act of legislation. Meanwhile, the owners of adjacent property should object to its employment, and the insurance companies should refuse the grant of policies on such property except on terms which it may please them to make.

English Mechanic and World of Science July 14, 1905, p. 515.


Says “We Shall Soon be Talking Round the World”.

As we said last week, Mr. Edison was reported to have said in an interview of the New York World that he did not believe with Tesla in being able to talk round the world, but that he thought Marconi would, sooner or later, perfect his system.

Nikola Tesla has replied. He says:

In the course of certain investigations which I carried on for the purpose of studying the effects of lightning discharges upon the electrical condition of the earth I observed that sensitive receiving instruments arranged so as to be capable of responding to electrical disturbances created by the discharges at times failed to respond when they should have done so, and upon inquiring into the causes of this unexpected behavior I discovered it to be due to the character of the electrical waves which were produced in the earth by the lightning discharges, and which had nodal regions following at definite distances the shifting source of the disturbances. From data obtained in a large number of observations of the maxima and minima of these waves I found their length to vary approximately from twenty-five to seventy kilometres, and these results and theoretical deductions led me to the conclusion that waves of this kind may be propagated in all directions over the globe, and that they may be of still more widely differing lengths, the extreme limits being imposed by the physical dimensions and properties of the earth. Recognising in the existence of these waves an unmistakable evidence that the disturbances created had been conducted from their origin to the most remote portions of the globe, and had been thence reflected, I conceived the idea of producing such waves in the earth by artificial means, with the object of using them for many useful purposes for which they are or might be found applicable.

Beat Lightning Flashes.

This problem was rendered extremely difficult, owing to the immense dimensions of the planet, and consequently enormous movement of electricity or rate at which electrical energy had to be delivered in order to approximate, even in a remote degree, movements or rates which are manifestly attained in the displays of electrical forces in nature, and which seemed at first unrealizable by any human agencies; but by gradual and continuous improvements of a generator of electrical oscillations, which I have described in my Patents Nos. 645,576 and 649,621, I finally succeeded in reaching electrical movements or rates of delivery of electrical energy not only approximately, but, as shown in comparative tests and measurements, actually surpassing those of lightning discharges and by means of this apparatus I have found it possible to reproduce, whenever desired, phenomena in the earth the same as or similar to those due to such discharges. With the knowledge of the phenomena discovered by me, and the means at command for accomplishing these results, I am enabled, not only to carry out many operations by the use of known instruments, but also to offer a solution for many important problems involving the operation or control of remote devices which, for want of this knowledge and the absence of these means, have heretofore been entirely impossible. For example, by the use of such a generator of stationary waves and receiving apparatus properly placed and adjusted in any other locality, however remote, it is practicable to transmit intelligible signals, or to control or actuate at will any one or all of such apparatus for many other important and valuable purposes, as for indicating whenever desired the correct time of an observatory, or for ascertaining the relative position of a body or distance of the same with reference to the given point, or for determining the course of a moving object, such as a vessel at sea, the distance traversed by the same or its speed; or for producing many other useful effects at a distance dependent on the intensity, wavelength, direction or velocity of movements, or other feature or property of disturbances of this character.

A Bit of Sarcasm.

Permit me to say on this occasion that if there exist to-day no facilities for wireless telegraphic and telephone communication between the most distant countries, it is merely because a series of misfortunes and obstacles have delayed the consummation of my labours, which might have been completed three years ago. In this connection I shall well remember the efforts of some, unwise enough to believe that they can gain an advantage by throwing sand in the eyes of the people and retarding the progress of invention. Should the first messages across the seas prove calamitous to them, it will be a punishment regrettable but fully deserved.

New York Sun
July 16, 1905


To the Editor of the New York Sun:

Everybody must have been pleased to learn that Commodore Peary has finally obtained the financial assistance which will enable him to start without further delay on his important journey. Let us wish the bold navigator the most complete success in his perilous undertaking, in the interest of humanity as well as for his own and his companions’ sake and the gratification of the generous donors who have aided him. But, while voicing these sentiments, let us hope that Peary’s will be the last attempt to reach the pole in this slow, penible and hazardous way.

We have already sufficiently advanced in the knowledge of electricity and its applications to avail ourselves of better means of transportation, enabling us to reach and to explore without difficulty and in a more perfect manner not only the North, but also the South Pole, and any other still unknown regions of the earth’s surface. I refer to the facilities afforded in this respect by the transmission of electrical energy without wires and aerial navigation, which has found in the novel art its ideal solution.

Many of your readers will, no doubt, be under the impression that I am speaking merely of possibilities. As a matter of fact, from the principles involved and the experiments which I have actually performed, not only is the practical success of such distribution of power reduced to a degree of mathematical certitude, but the transmission can be effected with an economy much greater than possible by the present method involving the use of wires.

It would not take long to build a plant for purposes of aerial navigation and geographical research, nor would it cost as much as might be supposed. Its location would be perfectly immaterial. It might be at the Niagara, or at the Victorian Falls in Africa, without any appreciable -difference in the power collected in a flying machine or other apparatus.

A popular error, which I have often opportunity to correct, is to believe that the energy of such a plant would dissipate itself in all directions. This is not so, as I have pointed out in my technical publications. Electricity is displaced by the transmitter in all directions, equally through the earth and the air; that is true, but energy is expended only at the place where it is collected and used to perform some work. To illustrate, a plant of 10,000 hp, such as I have been planning, might be running full blast at Niagara, and there might be but one flying machine, of, say, 50 hp operating in some distant place, the location being of absolutely no consequence. In this case 50 hp would be all the power furnished by the plant to the rest of the universe. Although the electrical oscillations would manifest themselves all over the earth, at the surface as well as high in the air, virtually no power would be consumed. My experiments have shown that the entire electrical movement which keeps the whole globe a-tremble can be maintained with but a few horsepower. Apart from the transmitting and receiving apparatus, the only loss incurred is the energy radiated in the form of Hertzian or electro-magnetic waves, which can be reduced to any entirely insignificant quantity.

I appreciate the difficulty which your non-technical readers must experience in comprehending the working of this system. To gain a rough idea, let them imagine the transmitter and the earth to be two elastic bags, one very small and the other immense, both being connected by a tube and filled with some incompressible fluid. A pump is provided for forcing the fluid from one into the other, alternately and in rapid succession. Now, to produce a great movement of the fluid in a bag of such enormous size as the earth would require a pump so large that it would be a greater task to construct it than to build a thousand Egyptian pyramids. But there is a way of accomplishing this with a pump of very small dimensions. The bag connected to the earth is elastic, and when suddenly struck vibrates at a certain rate. The first artifice consists in so designing and adjusting the parts that the natural vibrations of the bag are in synchronism with the strokes of the pump. Under such conditions the bag is set into violent vibrations, and the fluid is made to rush in and out with terrific force. But the immense bag – the earth, is still comparatively undisturbed. Its size, however, does not exempt it from the laws of nature, and just as the small bag, so too the earth, responds to certain impulses. This fact I discovered in 1899.

The second artifice is to so adjust the transmitter that it will furnish these particular impulses. When all is properly done the large bag is thrown into spasms of vibration, and the effects are bewildering. But no power is yet transmitted, and all this colossal movement requires little energy to maintain. It is like an engine running without load.

Next let your readers imagine that at any place where it may be desired to deliver energy a small elastic bag, not unlike the first, is connected to the large one through a tube. The third artifice consists in so proportioning the parts that the attachment will be responsive to the impulse transmitted, this resulting in a great intensification of the vibration of the bag. Still the pump will not furnish power until these vibrations are made to do work of some kind.

To conduce to an understanding of the fourth artifice, that of “individualization,” let your readers follow me a step further, and conceive the flow of energy to any point can be controlled from the place where the pump is located at will, and with equal facility and precision, regardless of distance, and, furthermore, through a device such as the combination lock of a safe, they will then have a crude idea of the processes involved. But only when they realize that all these and many other processes not mentioned, and related to one another like the links of a chain, are completed in a fraction of a second, will your readers be able to appreciate the magical potencies of electrical vibrations and form a conception of the miracles which a skilled electrician can perform by the use of these appliances.

I earnestly hope that in the near future the conditions will be favorable for the construction of a plant such as I have proposed. As soon as this is done it will be possible to adapt electrical motors to flying machines of the type popu-larized by Santos Dumont. There will be no necessity of carrying a generator or store of motive energy and consequently the machine will be much lighter and smal-ler. Owing to this and also to the greater power available for propulsion, the speed will be considerably increased. But a few of such machines, properly equipped with photographic and other appliances, will be sufficient to give us in a short time an exact knowledge of the entire earth’s surface. It should be borne in mind, however, that for the ordinary uses of a single person a very small machine of not more than one-quarter horse-power, corresponding to the work of two men, would be amply sufficient so that when the first plant of 10,000 hp is installed, the
com-modity of aerial flight can be offered to a great many individuals all the world over. I can conceive of no improvement which would be more efficient in the fur-therance of civilization than this.


Harvard Illustrated
March, 1907


By Nikola Tesla.

In the early part of 1900, still vividly impressed by certain observations, I had made shortly before, and feeling that the time had come to prepare the world for an experiment which will soon be undertaken, I dwelt on the practicability of interplanetary signalling in an article which appeared in the June number of Century Magazine of the same year. In order to correct an erroneous report which gained wide circulation, a statement was published in Collier’s Weekly of Feb. 9, 1901, defining my position in general terms. Ever since, my thoughts have been centred on the subject, and my original conviction has been strengthened both by reflection and suggestion.

Chief among the stimulating influences was the revelatory work of Percival Lowell, described in a volume with which the observatory, bearing his name, has honored me. No one can look at his globe of Mars without a feeling of profound astonishment, if not awe. These markings, still imperfectly discerned and incomprehensible, but evidently intended for a useful purpose, may they not contain a record of deep meaning left by a superior race, perhaps extinct, to tell its young brethren in other worlds of secrets discovered, of life and struggle, of their own terrible fate? What mighty pathos and love in such a gigantic drama of the universe’ But let us hope that the astronomer has seen true, that Mars is not a cold grave, but the abode of happy intelligent creatures, from whom we may learn. In the light of this glorious possibility, signalling to that planet presents itself as a preeminently practical proposition which, to carry out, no human sacrifice could be too great. Can it be done? What chance is there that it will be done?

These questions will be answered definitely the moment all doubt as to the existence of highly developed beings on Mars is dispelled. The straightness of the lines on Lowell’s map, their uniform width and other geometrical peculiarities, do not, themselves, appeal to me as strong proofs of artificiality. I should think that a planet large enough not to be frozen stiff in a spasm of volcanic action, like our moon, must, in the course of eons, have all its mountains leveled, the valleys filled, the rocks ground to sand, and ultimately assume the form of a smooth spheroid, with all its rivers flowing in geodetically straight lines. The uniform width of the waterways can be consistently explained, their crossings, however odd and puzzling, might be accidental. But I quite agree with Professor Morse, that this whole wonderful map produces the absolute and irresistible conviction, that these “canals” owe their existence to a guiding intelligence. Their great size is not a valid argument to the contrary. It would merely imply that the Martians have harnessed the energy of waterfalls. We know of no other source of power competent to explain such tremendous feats of engineering. They could not be accomplished by capturing the sun’s rays or abstracting heat imparted to the atmosphere, for this, according to our best knowledge, would require clumsy and inefficient machinery. Large falls could be obtained near the polar caps by extensive dams. While much less effective than our own, they could well furnish several billions of horse-power. It should be borne in mind that many Martian tasks in mechanical engineering are much easier than the terrestrial, on account of the smaller mass of the planet and lesser density, which, in the superficial layers, may be considerably below the mean. To a still greater degree this is true of electrical engineering. Taking into account the space encompassed by Mars, a system of wireless transmission of energy, such as I have perfected, would be there much more advantageously applied, for, under similar conditions, a receiving circuit would collect sixteen times as much energy as on the earth.

The astonishing evidences furnished by Lowell are not only indicative of organic life, but they make it appear very probable that Mars is still populated; and furthermore, that its inhabitants are highly developed intelligent beings. Is there any other proof of such existence? I answer, emphatically, yes, prompted both by an instinct which has never yet deceived me, and observation. I refer to the strange electrical disturbances, the discovery of which I announced six years ago. At that time I was only certain that they were of planetary origin. Now, after mature thought and study, I have come to the positive conclusion that they must emanate from Mars.

Life, as a great philosopher has said, is but a continuous adjustment to the environment. Similar conditions must bring forth similar automata. We can have no idea what a Martian might be like, but he certainly has sensitive organs, much as our own, responsive to external stimuli. The indications of these instruments must be real and true. A straight line, a geometrical figure, a number, must convey to his mind a clear and definite conception. He ought to think and reason like ourselves. If he breathes, eats and drinks, he is moved by motives and desires not very different from our own. Such colossal transformation as is observable on the face of Mars could not have been wrought except by beings ages ahead of us in development. What wonder, then, if they have maps of this, our globe, as perfect as Professor Pickering’s photographs of the moon? What wonder if they are signalling to us? We are sufficiently advanced in electrical science to know that their task is much easier than ours. The question is, can we transmit electrical energy to that immense distance? This I think myself competent to answer in the affirmative.

N. Tesla

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1. Quotes, Lecture, Newspaper reports from Nikola Tesla :