Category: invention


“Nature has provided an abundant supply of energy in various forms which might be utilized if proper means and ways can be devised. The sun’s rays falling upon the earth’s surface represent a quantity of energy so enormous that but a small part of it could meet all our demands. By normal incidence the rate is mechanically equivalent to about 95 foot pounds per square foot per second, or nearly 7,300 horse power per acre of ground. In the equatorial regions the mean annual rate is approximately 2,326 and in our latitudes 1,737 horse power for the same area. By using the heat to generate steam and operating a turbine under high vacuum probably 200 horse power per acre could be obtained as net useful power in these parts. This would be very satisfactory were it not for the cost of the apparatus which is greatly increased by the necessity of employing a storage plant sufficient to carry the load almost three-quarters of the time.

"The energy of light rays, constituting about 10% of the total radiation, might be captured by a cold and highly efficient process in photo-electric cells which may become, on this account, of practical importance in the future. Some progress in this direction has already been achieved. But for the time being it appears from a careful estimate, that solar power derived from radiant heat and light, even in the tropics, offers small opportunities for practical exploitation. The existing handicaps will be largely removed when the wireless method of power transmission comes into use. Many plants situated in hot zones, could then be operatively connected in a great super-power system to supply energy, at a constant rate, to all points of the globe.

"The sun emits, however, a peculiar radiation of great energy which I discovered in 1899. Two years previous I had been engaged in an investigation of radio-activity which led me to the conclusion that the phenomena observed were not due to molecular forces residing in the substances themselves, but were caused by a cosmic ray of extraordinary penetrativeness. That it emanated from the sun was an obvious inference, for although many heavenly bodies are undoubtedly possessed of a similar property, the total radiation which the earth receives from all the suns and stars of the universe is only a little more than one-quarter of one percent of that it gets from our luminary. Hence, to look for the cosmic ray elsewhere is much like chercher le midi dans les environs de quatorze heures [looking for lunch in the vicinity of fourteen o’clock]. My theory was strikingly confirmed when I found that the sun does, indeed, emit a ray marvelous in the inconceivable minuteness of its particles and transcending speed of their motion, vastly exceeding that of light. This ray, by impinging against the cosmic dust generates a secondary radiation, relatively very feeble but fairly penetrative, the intensity of which is, of course, almost the same in all directions. German scientists who investigated it in 1901 assumed that it came from the stars and since that time the fantastic idea has been advanced that it has its origin in new matter constantly created in interstellar space!! We may be sure that there is no place in the universe where such a flagrant violation of natural laws, as the flowing of water uphill, is possible. Perhaps, some time in the future when our means of investigation will be immeasurably improved, we may find ways of capturing this force and utilizing it for the attainment of results beyond our present imagining.”

-Nikola Tesla

“OUR FUTURE MOTIVE POWER.” Everyday Science and Mechanics, December 1931.

Soon after I left Mr. Edison’s employment a company was formed to develop my electric arc-light system. This system was adopted for street and factory lighting in 1886, but as yet I got no money — only a beautifully engraved stock certificate. Until April of the following year I had a hard financial struggle. Then a new company was formed, and provided me with a laboratory on Liberty Street, in New York City. Here I set to work to commercialize the inventions I had conceived in Europe.

After returning from Pittsburgh, where I spent a year assisting the Westinghouse Company in the design and manufacture of my motors, I resumed work in New York in a little laboratory on Grand Street, where I experienced one of the greatest moments of my life — the first demonstration of the wireless light.

I had been constructing with my assistants the first high-frequency alternators (dynamos), of the kind now used for generating power for wireless telegraphy. At three o’clock in the morning I came to the conclusion that I had overcome all the difficulties and that the machine would operate, and I sent my men to get something to eat. While they were gone I finished getting the machine ready, and arranged things so that there was nothing to be done, except to throw in a switch.

When my assistants returned I took a position in the middle of the laboratory, without any connection whatever between me and the machine to be tested. In each hand I held a long glass tube from which the air had been· exhausted. “If my theory is correct,” I said, “when the switch is thrown in these tubes will become swords of fire.” I ordered the room darkened and the switch thrown in — and instantly the glass tubes became brilliant swords of fire.

Under the influence of great exultation I waved them in circles round and round my head. My men were actually scared, so new and wonderful was the spectacle. They had not known of my wireless light theory, and for a moment they thought I was some kind of a magician or hypnotizer. But the wireless light was a reality, and with that experiment I achieved fame overnight.

Following this success, people of influence began to take an interest in me. I went into “society.” And I gave entertainments in return; some at home, some in my laboratory — expensive ones, too. For the one and only time in my life, I tried to roar a little bit like a lion.

But after two years of this, I said to myself, “What have I done in the past twentx-four months?” And the answer was, “Little or nothing.” I recognized that accomplishment requires isolation. I learned that the man who wants to achieve must give up many things — society, diversion, even rest — and must find his sole recreation and happiness in work. He will live largely with his conceptions and enterprises; they will be as real to him as worldly possessions and friends.

In recent years I have devoted myself to the problem of the wireless transmission of power. Power can be, and at no distant date will be, transmitted without wires, for all commercial uses, such as the lighting of homes and the driving of aeroplanes. I have discovered the essential principles, and it only remains to develop them commercially. When this is done, you will be able to go anywhere in the world — to the mountain top overlooking your farm, to the arctic, or to the desert — and set up a little equipment that will give you heat to cook with, and light to read by. This equipment will be carried in a satchel not as big as the ordinary suit case. In years to come wireless lights will be as common on the farms as ordinary electric lights are nowadays in our cities.

The matter of transmitting power by wireless is so well in hand that I can say I am ready now to transmit 100,000 horsepower by wireless without a loss of more than five percent in transmission. The plant required to transmit this amount will be much smaller than some of the wireless telegraph plants now existing, and will cost only $10,000,000, including water development and electrical apparatus. The effect will be the same whether the distance is one mile or ten thousand miles, and the power can be collected high in the air, underground, or on the ground.

-Nikola Tesla

“Making Your Imagination Work for You.” By M. K. Wisehart. The American Magazine, April 1921.

Nikola Tesla – The Father of Wireless Power

“The first result was one of the experiments which I at that time showed in a public lecture, motive devices operated by merely connecting them to one terminal of a source of oscillations–a high frequency coil.

I have often been told that my most important results in invention was the demonstration of the practicability of transmitting energy over one wire; because, once we can transmit energy over one wire we can use also the Earth, for the Earth is equivalent to a large conductor- a better conductor than copper wire.

This was one of the results I got, but the most striking one I will show you now.

"This second result shows how energy goes through space without any wire. That was a most striking experiment which was repeated all the world over and was published in thousands and thousands of papers. There is a field produced–of high frequency–and in this field I hold two tubes of glass in my hands. These glass tubes spring into powerful light. That was an experiment which carried the whole world by storm; but to me it was the first evidence that I was conveying energy to a distance, and it was a tremendous spur to my imagination and to my energy to develop what I had started.”

-Nikola Tesla

(Tesla explaining his wireless art in a pre-hearing interview with his legal counsel in 1916 to protect his radio patents from the Guglielmo Marconi and the Marconi Company.)

“Nikola Tesla On His Works With Alternating Currents and Their Application to Wireless Telegraphy, and Transmission of Power.” Twenty First Century Books, Breckenridge, Colorado, 2002.

“Tesla’s New Monarch of Machines.”

New York Herald, Oct. 15, 1911.

Noted Balkan Scientist Claims to Have Perfected an Engine That Will Develop Ten Horsepower to Every Pound of Weight, and Promises Soon to Give to the World a Flying Machine Without Wings, Propellers or Gas Bag. Characterizes Aeroplanes of Today as Mere Dangerous Toys Compared With the Safe and Stable Appliance Which Will Be Used in a Short Time to Dash Through the Air at a Speed Now Unimagined

Just what is your new invention?“ I asked.

"I have accomplished what mechanical engineers have been dreaming about ever since the invention of steam power,” replied Dr. Tesla. “That is the perfect rotary engine. It happens that I have also produced an engine which will give at least twenty-five times as much power to a pound of weight as the lightest weight engine of any kind that has yet been produced.

"In doing this I have made use of two properties which have always been known to be possessed by all fluids, but which have not heretofore been utilized. These properties are adhesion and viscosity.

"Put a drop of water on a metal plate. The drop will roll off, but a certain amount of the water will remain on the plate until it evaporates or is removed by some absorptive means. The metal does not absorb any of the water, but the water adheres to it.

"The drop of water may change its shape, but until its particles are separated by some external power it remains intact. This tendency of all fluids to resist molecular separation is viscosity. It is especially noticeable in the heavier oils.

"It is these properties of adhesion and viscosity that cause the "skin friction” that impedes a ship in its progress through the water or an aeroplane in going through the air. All fluids have these qualities–and you must keep in mind that air is a fluid, all gases are fluids, steam is fluid. Every known means of transmitting or developing mechanical power is through a fluid medium.

“Now, suppose we make this metal plate that I have spoken of circular in shape and mount it at its centre on a shaft so that it can be revolved. Apply power to rotate the shaft and what happens? Why, whatever fluid the disk happens to be revolving in is agitated and dragged along in the direction of rotation, because the fluid tends to adhere to the disk and the viscosity causes the motion given to the adhering particles of the fluid to be transmitted to the whole mass.  Here, I can show you better than tell you.”

Dr. Tesla led the way into an adjoining room.  On a desk was a small electric motor and mounted on the shaft were half a dozen flat disks, separated by perhaps a sixteenth of an inch from one another, each disk being less than that in thickness. He turned a switch and the motor began to buzz. A wave of cool air was immediately felt.

“There we have a disk, or rather a series of disks, revolving in a fluid–the air,– said the inventor. "You need no proof to tell you that the air is being agitated and propelled violently. If you will hold your hand over the centre of these disks–you see the centres have been cut away–you will feel the suction as air is drawn in to be expelled from the peripheries of the disks.

"Now, suppose these revolving disks were enclosed in an air tight case, so constructed that the air could enter only at one point and be expelled only at another–what would we have?”

“You’d have an air pump,” I suggested.

“Exactly–an air pump or blower,” said Dr. Tesla.

“There is one now in operation delivering ten thousand cubic feet of air a minute. "Now, come over here.”

He stepped across the hall and into another room, where three or four draughtsmen were at work and various mechanical and electrical contrivances were scattered about. At one side of the room was what appeared to be a zinc or aluminum tank, divided into two sections, one above the other, while a pipe that ran along the wall above the upper division of the tank was connected with a little aluminum case about the size and shape of a small alarm clock. A tiny electric motor was attached to a shaft that protruded from one side of the aluminum case. The lower division of the tank was filled with water.

“Inside of this aluminum case are several disks mounted on a shaft and immersed in a fluid, water,” said Dr. Tesla. “From this lower tank the water has free access to the case enclosing the disks. This pipe leads from the periphery of the case. I turn the current on, the motor turns the disks and as I open this valve in the pipe the water flows.”

He turned the valve and the water certainly did flow. Instantly a stream that would have filled a barrel in a very few minutes began to run out of the pipe into the upper part of the tank and thence into the lower tank.

“This is only a toy,” said Dr. Tesla. "There are only half a dozen disks" –runners,– I call them–each less than three inches in diameter, inside of that case. They are just like the disks you saw on the first motor–no vanes, blades or attachments of any kind.  Just perfectly smooth, flat disks revolving in their own planes and pumping water because of the viscosity and adhesion of the fluid. One such pump now in operation, with eight disks, eighteen inches in diameter, pumps four thousand gallons a minute to a height of 360 feet.“

We went back into the big, well lighted office. I was beginning to grasp the new Tesla principle.

"Suppose now we reversed the operation,” continued the inventor. "You have seen the disks acting as a pump. Suppose we had water, or air under pressure, or steam under pressure, or gas under pressure, and let it run into the case in which the disks are contained–what would happen?“

"The disks would revolve and any machinery attached to the shaft would be operated–you would convert the pump into an engine,” I suggested.

“That is exactly what would happen–what does happen,” replied Dr. Tesla. “It is an engine that does all that engineers have ever dreamed of an engine doing, and more. Down at the Waterside power station of the New York Edison Company, through their courtesy, I have had a number of such engines in operation.  In one of them the disks are only nine inches in diameter and the whole working part is two inches thick.  With steam as the propulsive fluid it develops 110-horse power, and could do twice as much.”

“You have got what Professor Langley was trying to evolve for his flying machine–an engine that will give a horse power for a pound of weight,” I suggested.

Ten Horse Power to the Pound.

“I have got more than that,” replied Dr. Tesla.  “I have an engine that will give ten horse power to the pound of weight. That is twenty-five times as powerful as the lightest weight engine in use today. The lightest gas engine used on aeroplanes weighs two and one-half pounds to the horse power. With two and one-half pounds of weight I can develop twenty-five horse power.”

“That means the solution of the problem of flying,” I suggested.

“Yes, and many more,” was the reply. "The applications of this principle, both for imparting power to fluids, as in pumps, and for deriving power from fluids, as in turbine, are boundless. It costs almost nothing to make, there is nothing about it to get out of order, it is reversible–simply have two ports for the gas or steam, to enter by, one on each side, and let it into one side or other. There are no blades or vanes to get out of order–the steam turbine is a delicate thing.“

I remembered the bushels of broken blades that were gathered out of the turbine casings of the first turbine equipped steamship to cross the ocean, and realized the importance of this phase of the new engine.

"Then, too,” Dr. Tesla went on, “there are no delicate adjustments to be made. The distance between the disks is not a matter of microscopic accuracy and there is no necessity for minute clearances between the disks and the case. All one needs is some disks mounted on a shaft, spaced a little distance apart and cased so that a fluid can enter at one point and go out at another. If the fluid enters at the centre and goes out at the periphery it is a pump. If it enters at the periphery and goes out at the center it is a motor.

"Coupling these engines in series, one can do away with gearing in machinery. Factories can be equipped without shafting. The motor is especially adapted to automobiles, for it will run on gas explosions as well as on steam. The gas or steam can be let into a dozen ports all around the rim of the case if desired. It is possible to run it as a gas engine with a continuous flow of gas, gasoline and air being mixed and the continuous combustion causing expansion and pressure to operate the motor. The expansive power of steam, as well as its propulsive power, can be utilized as in a turbine or a reciprocating engine. By permitting the propelling fluid to move along the lines of least resistance a considerably larger proportion of the available power is utilized.

"As an air compressor it is highly efficient. There is a large engine of this type now in practical operation as an air compressor and giving remarkable service. Refrigeration on a scale hitherto never attempted will be practical, through the use of this engine in compressing air, and the manufacture of liquid air commercially is now entirely feasible.

"With a thousand horse power engine, weighing only one hundred pounds, imagine the possibilities in automobiles, locomotives and steamships. In the space now occupied by the engines of the Lusitania twenty-five times her 80,000 horse power could be developed, were it possible to provide boiler capacity sufficient to furnish the necessary steam.”

“And it makes the aeroplane practical,” I suggested.

“Not the aeroplane, the flying machine,” responded Dr. Tesla. “Now you have struck the point in which I am most deeply interested–the object toward which I have been devoting my energies for more than twenty years–the dream of my life. It was in seeking the means of making the perfect flying machine that I developed this engine.

"Twenty years ago I believed that I would be the first man to fly; that I was on the track of accomplishing what no one else was anywhere near reaching. I was working entirely in electricity then and did not realize that the gasoline engine was approaching a perfection that was going to make the aeroplane feasible. There is nothing new about the aeroplane but its engine, you know.

"What I was working on twenty years ago was the wireless transmission of electric power. My idea was a flying machine propelled by an electric motor, with power supplied from stations on the earth. I have not accomplished this as yet, but am confident that I will in time.

"When I found that I had been anticipated as to the flying machine, by men working in a different field, I began to study the problem from other angles, to regard it as a mechanical rather than an electrical problem. I felt certain there must be some means of obtaining power that was better than any now in use. And by vigorous use of my gray matter for a number of years, I grasped the possibilities of the principle of the viscosity and adhesion of fluids and conceived the mechanism of my engine. Now that I have it, my next step will be the perfect flying machine.”

“An aeroplane driven by your engine?” I asked.

“Not at all,” said Dr. Tesla. "The aeroplane is fatally defective. It is merely a toy–a sporting play-thing. It can never become commercially practical. It has fatal defects. One is the fact that when it encounters a downward current of air it is helpless. The “hole in the air” of which aviators speak is simply a downward current, and unless the aeroplane is high enough above the earth to move laterally but can do nothing but fall.

“There is no way of detecting these downward currents, no way of avoiding them, and therefore the aeroplane must always be subject to chance and its operator to the risk of fatal accident. Sportsmen will always take these chances, but as a business proposition the risk is too great.

"The flying machine of the future–my flying machine–will be heavier than air, but it will not be an aeroplane. It will have no wings. It will be substantial, solid, stable. You cannot have a stable airplane. The gyroscope can never be successfully applied to the airplane, for it would give a stability that would result in the machine being torn to pieces by the wind, just as the unprotected aeroplane on the ground is torn to pieces by a high wind.

"My flying machine will have neither wings nor propellers. You might see it on the ground and you would never guess that it was a flying machine. Yet it will be able to move at will through the air in any direction with perfect safety, higher speeds than have yet been reached, regardless of weather and oblivious of "holes in the air” or downward currents. It will ascend in such currents if desired. It can remain absolutely stationary in the air, even in a wind, for great length of time. Its lifting power will not depend upon any such delicate devices as the bird has to employ, but upon positive mechanical action.“

"You will get stability through gyroscopes?” I asked.

“Through gyroscopic action of my engine, assisted by some devices I am not yet prepared to talk about,” he replied.

“Powerful air currents that may be deflected at will, if produced by engines and compressors sufficiently light and powerful, might lift a heavy body off the ground and propel it through the air,” I ventured, wondering if I had grasped the inventor’s secret.

Dr. Tesla smiled an inscrutable smile.

“All I have to say on that point is that my airship will have neither gas bag, wings nor propellers,” he said. “It is the child of my dreams, the product of years of intense and painful toil and research. I am not going to talk about it any further. But whatever my airship may be, here at least is an engine that will do things that no other engine ever has done, and that is something tangible.”

Nikola Tesla – The True Discoverer of the Rotating Magnetic Field

“Many erroneous statements have appeared in print relative to my discovery of the rotating magnetic field and invention of the induction motor which I was compelled to pass in silence. Great interests have waged a long and bitter contest for my patent rights; commercial animosities and professional jealousies were aroused, and I was made to suffer in more than one way. But despite of all pressure and efforts of ingenious lawyers and experts, the rulings of the courts were in support of my claims for priority in every instance without exception. The battles have been fought and forgotten, the thirty or forty patents granted to me on the alternating system have expired, I have been released of burdensome obligations and am free to speak…

”…A few words should be said in regard to the various claims for anticipation which were made upon the issuance of my patents in 1888, and in numerous suits conducted subsequently. There were three contestants for the honor, Ferraris, Schallenberger and Cabanellas. All three succumbed to grief. The opponents of my patents advanced the Ferraris claim very strongly, but any one who will peruse his little Italian pamphlet, which appeared in the spring of 1888, and compare it with the patent record filed by me seven months before, and with my paper before the American Institute of Electrical Engineers, will have no difficulty in reaching a conclusion. Irrespective of being behind me in time, Prof. Ferraris’s publication concerned only my split-phase motor, and in an application for a patent by him priority was awarded to me. He never suggested any of the essential practical features which constitute my system, and in regard to the split-phase motor he was very decided in his opinion that it was of no value. Both Ferraris and Schallenberger discovered the rotation accidentally while working with a Gullard and Gibbs transformer, and had difficulty in explaining the actions. Neither of them produced a rotating field motor like mine, nor were their theories the same as my own. As to Cabanellas, the only reason for his claim is an abandoned and defective technical document. Some over-zealous friends have interpreted a United States patent granted to Bradley as a contemporary record, but there is no foundation whatever for such a claim. The original application only described a generator with two circuits which were provided for the sole purpose of increasing the output. There was not much novelty in the idea, since a number of such machines existed at that time. To say that these machines were anticipations of my rotary transformer is wholly unjustified. They might have served as one of the elements in my system of transformation, but were nothing more than dynamos with two circuits constructed with other ends in view and in utter ignorance of the new and wonderful phenomena revealed through my discovery.“

–Nikola Tesla

“Some Personal Recollections.” Scientific American, June 5, 1915.

Nikola Tesla’s Remarkable Experiments With Wireless Lamps and Vacuum Tubes Shown Before the Franklin Institute and the National Electric Light Association in 1893

“These were the most striking results I showed in the transmission of energy… You see how far I have gone into the mastery of electrical vibrations in 1893. I stand here [Fig. 190] in the hall, holding a lamp in my hand, and the energy transmitted lights it. Here again [Fig. 191] I hold a phosphorescent bulb in my hand, and here [Fig. 192] a vacuum tube.

“These experiments, I remember, were made in St. Louis. There was a hall with 6,000 or 7,000 people. When I explained how I had shown a phosphorescent bulb to Lord Kelvin in England, and told them that the bulb was going to spring into light, and the current was turned on and it did burst into light, there was a stampede in the to upper galleries and they all rushed out. They thought it was some part of the devil’s work, and ran out. That was the way my experiments were received.”

–Nikola Tesla

(Tesla explaining his wireless art in a pre-hearing interview with his legal counsel in 1916 to protect his radio patents from the Guglielmo Marconi and the Marconi Company.)

“Nikola Tesla On His Works With Alternating Currents and Their Application to Wireless Telegraphy, and Transmission of Power.” Twenty First Century Books, Breckenridge, Colorado, 2002.

Ahead of his time.


“Radio Power will Revolutionize the World.” Modern Mechanix Publishing Co., Greenwich, Connecticut. July, 1934.