We give in what follows some liberal extracts from a recent paper in the Times, by John Foord, which is an excellent resumé of the remarkable investigations of Nikola Tesla!
“Of the energy that goes to the making of electric light over 99 per cent, is wasted.”
The statement is made on the authority of Nikola Tesla, and will be disputed by but few competent electricians. To explain the grounds on which it is made would be to elucidate some of the most elusive problems in physics, and to mark out the path of success for some of the most daring achievements of applied science. For, be it noted, it is electrical energy only of which Mr. Tesla speaks. No account is taken of the waste incurred in the steps of the process preceding the transformation of calorific into mechanical and mechanical into electrical energy.
Accepting Mr. Tesla’s startling assertion in all its breadth, what a preposterous dissipation there must be of the energy stored in a lump of coal between its first liberation by combustion and its final emergence in the form of electric light! The waste of heat energy begins in the furnace, and is continued at every step of the process of generation, transmission, and conversion of the steam, so that it is one of the oldest and most stubborn commonplaces of mechanical engineering that a practical engine does not utilize more than 16 per cent. and sometimes not even as much as 5 per cent. of the heat energy employed to operate it. Besides, there is the loss by mechanical friction, in most cases equal to 35 per cent. on an average load of the engine, and the loss by belt friction often equals 15 per cent. more — or 50 per cent. in all used up in the working of the engine itself, and in the transfer of the energy which it communicates to a piece of shafting. Even should that shaft be directly connected with an electric dynamo of good construction, there will be a further waste of certainly 10 per cent. in the dynamo itself. If the dynamo be worked in connection with an arc-lighting system, the loss will be as high as 30 per cent., because of the unsteadiness of the regulating mechanism. And, between the dynamo and the carbon filament, or pencil, which is made the center of an electric light, there ensues, as has been said, a loss of the potential energy conveyed to it of at least 99 per cent. To speak of the finality of scientific achievement in presence of waste on a scale like this is more than absurd.
In point of fact, science and her handmaid invention are advancing by deliberate but perfectly confident strides toward a much more economical conversion of available energy. In the case of electric light, one may accept the correctness of the statement that it is not probable that the incandescent lamp can be much improved, and yet be forced to acknowledge that by a single stroke of purely mechanical adaptation, the cost of producing the light may be reduced by one-half or even more. Suppose the steam engine and the electric generator or dynamo, instead of being separate, should be combined in one. Suppose that the average 35 per cent. of loss by mechanical friction in the working of the engine should be saved, likewise the 15 per cent. of loss by belt friction and the 10 per cent. wasted in the dynamo, there would clearly be an addition of 60 per cent. to the available energy obtained from the steam for the purpose of producing electricity. Suppose, further, that the consolidated machine is much simpler, smaller, and lighter than the mechanism which it is to replace; suppose it to be absolutely constant in its action, automatically regulated, and therefore subject to the least possible amount of wear and tear, its advent would certainly mark a revolution, not only in the equipment of electric-light stations, but in many other fields of applied energy. These requirements Mr. Tesla seems to have met in the invention of the “oscillator.”
The primary purpose of the “oscillator” is to convert by a process as direct as possible the energy of steam into that of electricity. It has no rotary motion, because for its purpose rotary motion is not only unnecessary, but wasteful. If it be a question of generating electricity for the production of light, all rotary motion in the mechanism is merely so much dissipation of energy. For that and other reasons there can be no doubt about the impression which the “oscillator” will make in the lighting business. But if the machine does all that its inventor believes it can and will, it is also destined to have a very profound influence indeed on all the great agencies of production and transportation. The fact is already recognized by all progressive men that the cheapest way of distributing power is by means of electricity. To say nothing about the enormous frictional losses due to the employment of extended systems of shafting and belting, account must be taken of the power wasted in moving long lines of shafting for the purpose of operating the small part which may be actually in use. When the distribution of power is made by electric energy, it is used only when and where it is needed.
Now, since it is recognized that it is most economical to convert the energy of the steam first into electricity, and then reconvert it into any form of motion that may be required, it is clear that the most successful apparatus of power production adapted to modern needs will be the one best fitted for the simple, direct, and economical generation of electricity. Mr. Tesla has taken what may be called the core of a steam engine and the core of an electrical dynamo, given them a harmonious mechanical adjustment, and produced a machine which has in it the potentiality of reducing to the rank of old metal half the machinery at present moving on the face of the globe. It may come to do the work of the engines of an ocean steamship within a small part of the space they occupy and at a fraction of their cost, both of construction and operation. It will do the work, if at all, without jar or pounding, and will reduce to a minimum the risk of derangement or breakage. There is nothing in the whole range of mechanical construction, from railway locomotives to stamp mills, which such an invention may not revolutionize.
When the key is found to the elimination of the 99 per cent. of waste incidental to the production of electric light, then that consummation will not be far from our grasp. But, let it be noted that, however efficient the machine already referred to may prove to be in reducing the cost of generating the electricity that goes to the production of light, it marks only the first step toward the solution of the larger problems in the working out of which it is to serve as a tool. The scientific as distinguished from the commercial value of the new machine, consists, in its capacity to produce very rapidly alternating currents of electricity whose frequency, i.e., rate of oscillation, whether high or low, is absolutely constant. Further progress in the direction whither Mr. Tesla’s experiments are leading was all but impossible while the latter requirement was lacking. Some of the factors of the problem which Tesla has set out to solve elude popular definition, and some, indeed, almost transcend comprehension. But when it is stated that light is the result of etheric vibration of a very high pitch and of definite kind, much higher than the heat-producing vibrations, we get some grasp of the idea that light production must be wasteful while it continues to be impossible to obtain the higher light vibrations without passing through the lower heat vibrations. No apparatus yet designed for the production of light by conversion from any source of energy, whether the process be electrical, chemical, or other, has been able to avoid that necessity. Escape from it seems to be as impossible as from that of imparting to a body a certain velocity without passing through all lower velocities.
But we shall not be able to follow very far in the path which the advanced guard of modern science is treading if the laws of what we have been accustomed to call matter are regarded as the measure of the universe. Matter is a term whose significance science has greatly enlarged. It has become a scientific postulate that what is commonly called the void of space is filled with a medium which, though imperceptible to any human sense, has yet material properties. That is to say, the all-enveloping, all-pervading, ether — the eternal ocean without a shore, in whose immensity suns and planets are but bubbles of varying size and hue — is the carrier and transmitter of all primary forms of energy, and perhaps is the material from which the tangible and visible universe has come. The question of the schoolbooks is relevant here: “If light is motion, what moves?” Beyond that thin envelope that we call the earth’s atmosphere, there are the depths of interplanetary space, through which must be communicated to us the form of energy known as light. But as the science primers again remark, “empty space can neither receive nor communicate motion.” And so we come to the only hypothesis that accords with the facts, that of the etheric atoms, namely, and the sublime expectations to which that theory has given birth. The inconceivably minute atom, “the ulterior element of the universe’s structure, is tossed about,” as Tesla puts it, “in space eternally, a play to external influences, like a boat in a troubled sea.” It moves, it vibrates, and that with the most marvelous rapidity, and by the very necessity of its existence, for matter at rest would be dead matter — quite an inconceivable thing, in spite of the popular impression to the contrary.
Science says that light must travel at the rate of 186,000 miles a second, and that light is the product of an etheric vibration whose rate is about 500,000,000,000,000 a second, but science has hardly stopped to consider what profound possibilities there are in the forces which such appalling figures convey. Even now we know very little of what electricity is, but it has been one of the triumphs of modern investigation to identify electro-magnetic manifestations of energy with those of light and heat. Out of this identification has been born the desire to reach to the very source of all the transformed, accumulated, and stored up supplies of this energy — such as coal, gas, and oil — which there is so much waste in liberating from their mundane environment, and to take a lead directly from the inexhaustible fountain of it all. It is toward such an ideal that Tesla is constantly striving.
In his London lecture of two years ago, Tesla demonstrated not only the fallacy of the idea that an electric motor could be operated only with a double connection between it and the generator — that is, with a wire for the return, as well as the transmission of the current — but he showed that the motor could be operated with one wire only, or without any connecting wire at all. In his own words: “It is not necessary to have even a single connection between the motor and the generator, except, perhaps, through the ground; for not only is an insulated plate capable of giving off energy into space, but it is likewise capable of deriving it from an alternating electrostatic field, though in the latter case the available energy is much smaller.” Now, from this demonstration of the possibility of working a motor without connecting wires by currents passed through the earth or air, a far-reaching possibility is revealed. For, “alternate currents, especially of high frequencies, pass with astonishing freedom through even slightly rarefied gases. To reach a number of miles into space requires the overcoming of difficulties of a merely mechanical nature. There is no doubt that with the enormous potentials obtainable by the use of high frequencies and oil insulation, luminous discharges might be passed through many miles of rarefied air, and that, by thus directing the energy of many hundreds of thousands of horse power, motors or lamps might be operated at considerable distances from the stationary sources.”
This is a sufficiently impressive perspective, but it is referred to by Tesla only as a possibility, for, dipping into the future further than most human eyes can see, he asserts that we shall have no need to transmit power in this or any other way. “We shall have no need to transmit power at all. Ere many generations pass, our machinery will be driven by a power obtainable at any point of the universe. * * * Throughout space there is energy. Is this energy static or kinetic? If static, our hopes are in vain; if kinetic — and this we know it is for certain — then it is a mere question of time when men will succeed in attaching their machinery to the very wheelwork of nature.” To state this in ordinary language, if we live amid a medium through which there is no continuous flow of energy, this realization would appear to be impossible, but if everything around us is in constant motion, then human ingenuity must find a means of converting that energy to productive uses.
Here we have indeed the fairy tales of science, but, rightly considered, no more marvelous than many things we have long ceased to wonder at, because they are so familiar.
Take the problem of the incandescence of the filament in the bulb. Here atmospheric air has been exhausted, not by any means perfectly, it is true, but as near an approach to what is called a vacuum has been made as is usual in commercial appliances. A “vacuum” is, however, merely a relative term. In addition to a certain residue of atmospheric air, the etheric medium remains, for, as the text-books put the case, “an attempt to pump it out of space would be like trying to pump water with a sieve for a piston,” and a sieve, it may be added, with very wide meshes indeed. When the electric vibrations passed along the wire are communicated to the filament within the bulb, they cause a disturbance of its molecules, so violent as to produce both heat and light, but, to the despair of the man of science, unfortunately, very little of the latter. Light comes as the filament gives out an incandescent glow, but the light would be a much more economical one if the molecules or atoms of the surrounding gas or ether could be made to glow, too. And here we encounter one of the most instructive of the Tesla paradoxes, which can be best expressed in his own words: “Any one who begins a study of the problem will be apt to think that what is wanted in a lamp with an electrode is a very high degree of incandescence of the electrode. There he will be mistaken. The high incandescence of the button is a necessary evil, but what is really wanted is the high incandescence of the gas surrounding the button. In other words, the problem in such a lamp is to bring a mass of gas to the highest possible incandescence.”
To follow this idea further, it is necessary to distinguish between the origin of the incandescence of the filament and that of a mere button at the end of the conducting wire of the lamp. In the case of the filament, the luminosity is due partly to the action of its component molecules on each other when excited by the electric current, and partly to the bombardment or impact of the etheric particles, which have also received their electric charge and are being attracted, repelled, and agitated with tremendous velocity. The incandescence of the button, on the other hand, is caused almost solely by its very active bombardment by these inconceivably minute electrified atoms of the gas or ether. And here we begin to see why Mr. Tesla believes that the production of a small electrode (or terminal button) capable of withstanding enormous temperatures is of the greatest importance in the manufacture of light. For, as he explains it, “the intensity of the light emitted depends principally on the frequency and potential of the impulses and on the electric density on the surface of the electrode. It is of the greatest importance to employ the smallest possible button, in order to push the density very far. Under the violent impact of the molecules of the gas surrounding it, the small electrode is of course, brought to an extremely high temperature, but around it is a mass of highly-incandescent gas, a flame photosphere many hundred times the volume of the electrode.”
So far, the problems of practical adaptation, which, however important and interesting, appeal less powerfully to the imagination than the higher lights of the Tesla experiments. But Tesla never flies so high as to forget the “one and only desire” which he shares with all lovers of science and of progress, “to reach a result of utility to men in any direction to which thought or experiment may lead.” So when he shows how a hollow glass tube, from which the air has been exhausted before being sealed at each end, can be made to glow with light throughout its entire length by the mere act of holding it in the hand in a room in which electrostatic forces of sufficient strength have been made to act, he is thinking how such experiments may lead to the production of an efficient illuminating device. For, as he puts it, “every thinker, when considering the barbarous methods employed, the deplorable losses incurred in our best system of light production, must have asked himself: What is likely to be the light of the future? Is it to be an incandescent solid, as in the present lamp, or an incandescent gas, or a phosphorescent body, or something like a burner, but incomparably more efficient?”
In such a quest one may, however, soar very high. Take the very striking and beautiful vacuum-tube experiment to participate in which makes one feel as if the veritable scepter of the world of light were put in one’s hand, what does the experimenter mean when he says that his conviction has grown strong that “to whatever kind of motion light may be due, it is produced by tremendous electrostatic stresses vibrating with extreme rapidity? That raises the further question of what is electrostatic force, and here let Tesla speak for himself: “It is the force which governs the motion of the atoms, which causes them to collide and develop the life-sustaining energy of heat and light, and which causes them to aggregate in an indefinite variety of ways, according to Nature’s fanciful designs, and form all these wondrous structures we see around us; it is, in fact, if our present views be true, the most important force for us to consider in nature.” To establish what is called an electrostatic alternating field, acting through the whole extent of a room, requires an adjustment of electrical apparatus whose description belongs to technical, not to popular study. Let it suffice to say that when two conducting bodies are insulated and electrified an electrostatic force is said to be acting between them. “This force manifests itself in attractions, repulsions, and stresses in the bodies and space or medium without. So great may be the strain exerted in the air, or whatever separates the two conducting bodies, that it may break down, and we observe sparks or bundles of light or streamers, as they are called.” To demonstrate the potency of such a force, the experimenter, standing within an electrostatic field in whose creation a peculiar induction coil plays an important part, brings a piece of metal which he holds in his hand in touch with the end of the secondary wire of the coil. His arm is then traversed by a powerful electric current, vibrating at about the rate of 1,000,000 times a second.
All around the electrostatic force makes itself felt and the air molecules and particles of dust flying about are acted upon and are hammering violently against his body. So great is this agitation of the particles that when the lights are turned out streams of feeble light are seen to appear on some parts of the body. When such a “streamer” breaks out it produces a sensation like the pricking of a needle. Were the potentials, or pressures, sufficiently high, and the frequency of the vibration, or rapidity, rather low, the skin would probably be ruptured under the tremendous strain and the blood would rush out with great force in the form of fine spray or jets so thin as to be invisible. The streams of light which are the most frequently cited, and overstated of the Tesla marvels, are due to a potential of about 200,000 volts, alternating in rather irregular intervals but, as already stated, at something like 1,000,000 times a second.
But such an experiment, however well calculated to dazzle and amaze, has a significance much less profound than the production inside of an exhausted glass tube of a luminous thread possessing rigidity. This is one of Tesla’s most beautiful and most significant demonstrations, and it appeals very powerfully to the scientific imagination, because it touches some of the most occult processes of the arcanum of nature. As Mr. Tesla puts it, “the demonstration of the fact that a vibrating, gaseous column possesses rigidity, must greatly modify the views of thinkers. When with low frequencies and insignificant potentials indications of that property may be noted, how must a gaseous medium behave under the influence of enormous electrostatic stresses which may be active in the interstellar space, and which may alternate with inconceivable rapidity? The existence of such an electrostatic, rhythmically-throbbing force — of a vibrating, electrostatic field — would show a possible way how solids might have formed from the ultra-gaseous uterus, and how transverse and all kinds of vibrations may be transmitted through a gaseous medium filling all space.”
Sie itur ad astra! And thus we reach celestial heights of contemplation, even as we search for higher forms of incandescence, to light the murky nights of this little planet withal. This is to have the insight of the poet joined to the tireless patience of the seeker after exact truth, to have a philosophic mind quickened by imagination, and a penetrating intelligence directed by the enthusiasm of humanity. This is to be advancing without haste, but without rest, with a serene and modest certainty toward the goal of achievements which will give the next century its characteristic distinction, as surely as the triumphs of steam have stamped their influence on the one now drawing to a close. This is to be a scientist, inventor, and seer in one, to be one of the most remarkable men of this or any other time — to be Nikola Tesla.