Tesla and His Ruined Laboratory

The ordinary newspaper-reader, as well as the man of science, was grieved to read, the other day, of the loss that had befallen Nikola Tesla, in the entire destruction by fire of his laboratory with its valuable and wonderful electrical devices. It is fortunate that just before this untoward event a popular description of these devices had been written by Mr. Thomas C. Martin, who enjoyed the confidence of the inventor and had full access to all of his inventions. From this article, which appears in The Century Magazine, April, we quote some extracts below. Perhaps the most advanced of Tesla's recent inventions-at least, in the commercial sense-was his oscillator or engine and dynamo in one. After speaking of the great waste of energy in the ordinary combination of engine and dynamo, Mr. Martin says:

"The old-fashioned electric-light station or street-railway powerhouse is a giddy maze of belts and shafting: in the later plants engine and dynamo are coupled directly together on one base. This is a notable stride, but it still leaves us with a dynamo in which some part of the wire wound on it is not utilized at every instant, and with an engine of complicated mechanism. The steam-cylinder, with its piston, is the only thing actually doing work, and all the rest of the imposing collection of fly-wheel, governor-balls, eccentrics, valves, and what not, is for the purpose of control and regulation.

"In his oscillator Mr. Tesla, to begin with, has stripped the engine of all this governing mechanism. By giving also to the coils in which the current is created as they cut the lines of force' of the magnets, a to-and-fro or reciprocating motion, so that the influence on them is equal in every direction, he has overcome the loss of the idle part of the wire experienced in rotating armatures: and, moreover, greatest achievement of all, he has made the currents regulate the mechanical motions.... For the same pressure and the same piston speed the engine has about one thirtieth or one fortieth of the usual weight, and occupies a proportionally smaller space....

"If one watches any dynamo, it will be seen that the coils constituting the 'armature' are swung around in front of magnets, very much as a turnstile revolves inside the barricading posts.... In the Tesla oscillator, the rotary motion of the coils is entirely abandoned, and they are simply darted to and fro at a high speed in front of the magnets, thus cutting the lines of the field of force' by shooting in and out of them very rapidly, shuttle-fashion. The great object of cutting as many lines of an intense field of force as swiftly, smoothly, regularly, and economically as possible is thus accomplished in a new and, Mr. Tesla believes, altogether better way."

With the currents from this ingenious machine-currents of high tension, high frequency, but at the same time of such great regularity that his oscillator might be used to mark time like a clock-Mr. Tesla has obtained striking results in lighting, not only with the ordinary glow-lamp but with other far different devices. Says the author:

"It had been commonly supposed that the light-giving conductor in the lamp, to be efficient and practical, should be fine; hence the name 'filament' given to the carbon loop in such lamps. But with the Teslaic currents the resistance or friction of the filament to the flow of current does not count for anything: the filament may just as well be short and thick, for it will rapidly reach and steadily maintain proper incandescence by the passage of a small current of the right high frequency and potential. An action is set up as the result of which the filament is hit millions of times a second by the bombardment of the molecules around it in a merciless ring of tormentors. The vibrations of the current in similar manner will cause the infinite jostling of the molecules of solid and gas against a small polished carbon or metallic button or bar in a lamp, and brilliant light is also obtainable this way."

But the most startling of all Tesla's effects are those in which he throws aside conduction altogether and relies upon the production in free space of a powerful vibrating electric field. By this. means he can for instance cause to glow lamps that are totally unconnected in the usual way with the source of electricity. These results were partially described and illustrated last year in this department of The Digest. Mr. Martin describes these at length, and also experiments analogous to those of D'Arsonval, pictured not long ago in these columns, in which powerful alternating currents, harmless because of their high frequency, are passed through the human body without inconvenience, and then goes to say:

"Reference has been made to the 'resonating' quality of the circuits and coils. It would be wearisome, and indeed is not necessary, here to dwell on the difficulty often experienced in establishing the relation of 'resonance, the with which it can be disturbed. It may be stated, in order to give some idea of the conditions to be observed in these experiments, that when an electric circuit is traversed by a rapidly oscillating current which sets up waves in the ether around the wire, the effect of these waves upon another circuit... is most pronounced when the second circuit is so adjusted that its period of vibration is the same as that of the first.... In very exact adjustments, minute changes will completely upset the balance, and the very last straw of fine wire, for example, in the induction-coil which gives the self-induction will break the spell. As Mr. Tesla has said, it is really a lucky thing that pure resonance is not obtainable; for if it were, all kinds of dangers might lie in store for us by the increasing oscillations of every kind that would be set up. It will, however, have been gathered that if one electrical circuit can be tuned to another effectively, we shall need no return wire, as heretofore, for motors or for lights, the one wire being, if any. thing, better than two, provided we have vibration of the right value; and if we have that, we might get along without any wires or any 'currents.'"

Mr. Tesla has thus been led to the opinion that we may one day learn to transmit messages directly through the Earth. He has tried many experiments looking toward the determination of the electrical capacity of the Earth, by means described by Mr. Martin in the following words:

"With the oscillator, if he has not as yet actually determined the Earth's electrical charge or 'capacity,' he has obtained striking effects which conclusively demonstrate that he has succeeded in disturbing it. He connects to the Earth, by one of its ends, a coil in which rapidly vibrating currents are produced, the other end being free in space. With this coil he does actually what one would be doing with a pump forcing air into an elastic foot-ball. At each alternate stroke the ball would expand and contract. But it is evident that such a ball, if filled with air, would, when suddenly expanded or contracted, vibrate at its own rate. Now if the strokes of the pump be so timed that they are in harmony with the individual vibrations of the ball, an intense vibration or surging will be obtained. The purple streamers of electricity thus elicited from the Earth and pouring out to the ambient air are marvelous.

"The currents which are made to pass in and out of the Earth by means of this coil can also be directed upon the human body. An observer mounted on a chair, and touching the coil with a metal rod, can, by careful adjustments, divert enough of it upon himself to cause its manifestation from and around him in splinters of light. This halo effect, obtained by sending the electricity of the Earth through a human being - the highest charge positively ever given in safety - is, to say the least, curious, and deeply suggestive. Mr. Tesla's temerity in trying the effect first upon his own person can be justified only by his close and accurate calculation of what the amount of the discharge from the earth would be."

We conclude by quoting Mr. Martin's closing paragraph:

"Here are great results, lofty aims, and noble ideas; and yet they are but a beggarly few of all those with which Mr. Tesla, by his simple, modest work, has associated his name during recent years. He is not an impracticable visionary, but a worker who, with solid achievements behind him, seeks larger and better ones that lie before, as well as fuller knowledge. I have ventured to supplement data as to his late inventions by some of his views as to the ether, which throughout this presentation of his work has been treated familiarly as the maid-of-all-work of the universe. All our explanations of things are but half-way houses to the ultimate facts. It may be said, then, in conclusion, that while Mr. Tesla does not hold Prof. Oliver Lodge's ingenious but intricate notion of two electricities and two ethers, and of the ether as itself electricity, he does belong to what Lord Kelvin has spoken of as the Nineteenth Century school of plenum, accepting one ether for light, heat, electricity, and magnetism, outward manifestations of an inward unity whose secret we shall some day learn."