Nikola Tesla - His Discoveries in Electricity

In a brief but pregnant comment on the destruction by fire of the workshop of Nikola Tesla, the New York "Sun" remarked: "It is not in any degree an exaggeration to say that the men living at this time who are more important to the human race than this young gentlemen can be counted on the Angers of one hand; perhaps on the thumb of one hand." There is perhaps no man now writing for newspapers whose culture is so many-sided and whose accomplishments range over so wide a field of human effort as those of the editor of the "Sun." The brevet rank of immortality conferred by an authority so competent challenges attention to the work of the man whom he deems worthy of placing on the pinnacle of fame. Reference to the practical aspect of that work has been made from time to time in these columns. But public curiosity about it has only begun to demand some intelligible exposition of its scope and parpose. Even among electricians it is but imperfectly understood, and there are the most widely divergent opinions as to its character and significance. It is about ten to one that the mention of the name of Nikola Tesla in a company of ordinary Intelligence will merely elicit the inquiry, "What has he done?" This question Mr. Thomas Commerford Martin essays to answer in the April number of the "Century," and brings to the task a felicity and accuracy of expository method well calculated to adorn and illumine the subject. Mr. Martin's richly illustrated and carefully digested study of Tesla will render it somewhat easier to put in popular language a reply to the popular question, but it suggests also the conclusion that for some time to come the greatest electrician of our time must continue to be an enigma to those whose only intelligible measure of achievement is that of tangible results and commercial valuation. The more distant an object is from the eye the more difficult is it to realize the rapidity of its movement, and the researches of Tesla are so far removed beyond the ken of most of us that we may watch him with a sensation such as that with which we regard bodies moving with prodigious velocity through interstellar pace, but whose apparent position remains unchanged.

Two years ago Mr. Tesla publicly declared that he was becoming dally more convinced of the practicability of transmitting intelligible signals or perhaps even power to any distance without the use of wires. He had already demonstrated that electric vibration might be transmitted through a single conductor, that is, that there was no necessity to employ a wire as a conductor of the return current. But if the earth may serve for one purpose, why not for both? Treating the earth in common with the air simply as a conductor of electrical vibration, and remembering the tremendous rapidity with which an electric disturbance may be propagated through the earth, there is nothing visionary in the claim that alternating currents might be passed through it from one source of electrical energy to another. The pendulous swing of the wave-like action of electricity might, in short, be indefinitely diffused by a series of sources of alternating currents working in perfect synchronism, that is, giving out electric energy of precisely the same period of vibration. This would be like moving a pendulum over a given arc of space by the application at either side of exactly the force needed to send it to the end of its swing on the other.

But if the earth, in addition to being a conductor of electricity, has itself a fixed electric charge, the possibility of using it as a vehicle for the transmission of electric energy becomes much more impressive and brilliant. For, as electricity behaves like an incompressible but elastic fluid, the slightest pressure applied to it at one point must be felt at all other points over which it is diffused. But pressure cannot be applied to the subtle and occult form of energy which we call electricity except by a similar phase of the same force. In other words, if the earth be an electrically charged body insulated in space, its charge can be disturbed only by an oppositely electrified system or known circuit whose period of vibration corresponds in some way with that of the charge of the earth. It is not enough to pump electricity into the earth to excite a reflex action in the electricity already there. The period of vibration of the energy pumped in must in certain essential respects correspond to the period of that with which the earth is charged to send the latter oscillating so as to produce in some perceptible degree what the electricians call "resonance."

This is the work to which Mr. Tesla has given most of the last few years of his life. The elusive difficulty of the task can be but imperfectly conceived even by those who know something of the scientific conditions of the problem. If the earth were a great tuning fork which would vibrate in unison with but one unknown note, it would be a comparatively simple problem to run up and down the gamut of tone to discover the precise combination of sound waves to which the globe would thrill in responsive music. But the gamut of electric vibration is so vast, and in the range of its period from low to high there is such an infinite series of combinations, that the attempt to find what may be called the fundamental note of the cosmic charge of electricity sounds like the effort of a dreamer. It has, nevertheless, been conducted in a very practical way, and has already begun to yield some highly practical results. If the true note has not yet been struck, some notes to which it is partially responsive have been. The electrical charge of the earth is no longer an inert force to human touch; under the wonder-working hands of Tesla it has moved and stirred, and in the purple streamers of lambent lightning which leaped at its impulse from the apex of the return wire in the now vanished laboratory there was the promise of such achievement as I will cast into the shade all that science has yet accomplished for man.

Tesla is deeply impressed with the idea that all that man has yet done toward bending the forces of nature to his service is but feeble and tentative compared with what there is left for him to do. To have two electrical instruments move in unison though unconnected by wires and divided by half the globe, seems a marvellous not to say incredible achievement. But a much more marvellous thing than that is witnessed when simultaneously with the appearance of a white spot on the face of the sun there ensues a general disturbance of magnetic needles, and telegraphy is greatly interrupted by "earth currents" on this little globe of whose distances we make so much. If distance is an element in the problem, telegraphy without wires across an interval of ninety-two millions of miles must surely be less conceivable than a similar process over a distance of six thousand miles. To say that we cannot reduplicate the gigantic forces of nature is to beg the whole question for all the scientific achievements of men have been merely the subjugation of the forces of nature to their service. ordinary flame gives light and heat no less An than the sun, and the light produced by both is equally the result of vibrations so inconceivably rapid that the force which they represent would, mechanically measured, be equivalent to a pressure of thousands of tons per square inch. Man can liberate by the simplest effort forces truly gigantic, but he is only beginning to learn how to employ them. Above all, he is only beginning to discover that his empire over nature is to be found in the coordination of forces in nature's own way.

It is in this direction that it will be reckoned the crowning glory of Tesla to have led his generation. A bolder or more original inquirer science has never numbered among her votaries; a man combining in a higher degree the patience of the investigator, the modesty of the student and the Intuitive perception of genius the world has not seen. What other men have regarded as the limit of human attainment has been to him merely the beginning of a new domain of scientific conquest. Since he startled the electrical world with the principle of the rotating magnetic field his advance has been swift, continuous, irresistible. The world at large will better appreciate this when a scientific tool of his — the oscillator — invented in response to the necessity of producing electric vibrations of absolute constancy, becomes a commercial factor in cheapening by one-half the cost of light and increasing fourfold the effective energy of steam. But the interpretation of the secrets of nature which is destined to make his name immortal, will go on consuming years of a life dominated by an intensity of effort beyond that of which most men are capable, and people may go on asking, "what has he done?" forgetful how long may be the journey of one who has set his goal beyond the limit of achievement dreamed of by the most daring and farsighted of his contemporaries.

JOHN FOORD.