Nikola Tesla - Early News of the Alternating Current - 1893

The Woodland Daily Democrat, Woodland, California, Saturday Evening, June 24, 1893.


Electric Currents That Produce Variegated Streams of Mysterious Light and Fail to Heat the Wires That Carry These Wonderful Currents.
Almost from the time that the vibratory theory of light was accepted scientific men have looked forward to the day when it would be possible to produce light without heat. For it is an unfortunate fact that so far every effort to produce light has been accompanied by an enormous waste of energy due to the production of useless heat. The simplest way of producing light is by means of the combustion of some compound of carbon. It does not matter whether the carbon is solid, as in a candle, or a fluid, as in a lamp, or in a gas, as in ordinary illuminating gas, the process is the same.

The union of the carbon of the substance with the oxygen of the air produces the rapid vibration that the eye recognizes as light. Carbon, though the element usually employed, is not a necessary factor, for magnesium, potassium, iron--indeed almost any of the elements--will take its place. Neither is oxygen a necessary part in the production of light. Chlorine will produce an even more brilliant light with certain substances. It is evident, therefore, that the rate of vibration and not the element employed is the principal factor in producing light.

Unfortunately all methods of producing lights by means of chemical combinations (such as the union of the carbon of the candle with the oxygen of the air) are accompanied by a very large production of heat waves, which in the majority of cases are utterly useless, if not absolutely troublesome. The old simile of a musician desiring to produce a certain high note being compelled to press down all the keys of his instrument is an apt one. The lower notes are not merely useless, but they are positively annoying.

Singularly enough, the first solution of the problem that was attempted successfully was by the aid of heat. A very small amount of light waves are required for recognition by the wonderfully developed special sense which man possesses. It is intensity, not quantity, that is wanted, to use a technical term. Consequently if a very small particle is heated to incandescence the light which it throws out bears a far greater ratio to the amount of heat required than it does if a large mass is similarly heated.

This is one of the radical bases of the utility of the incandescent electric light. An extremely small filament is heated to incandescence through the resistance which it offers to the flow of an electric current. It generates heat, it is true, but the amount of heat thus produced is directly proportional to the mass of the carbon, which is very small. The light produced, however, is amply sufficient for all ordinary purposes.

This solution, however, is highly unsatisfactory to scientists, however useful it is to the public at large. Light apart from heat altogether was wanted. The firefly, the phosphorescent sea animalcules and even the exhausted tubes of Geissler furnished the hope that there was yet some method of reaching the high note without pressing down the whole keyboard.

Recently an extraordinary genius has appeared in this country who seems upon the verge of discovering, if not to have actually discovered, a method by which this might be done. Nikola Tesla, a man of independent fortune and most brilliant mind, who was for a time connected with Edison, has dared to experiment with rapidly alternating electric currents. The result has surprised the wildest dreams of theorizers. He has succeeded in producing light of comparatively high intensity without the production of heat and apparently directly by the use of electricity. The halls of the Royal society of London and of the Franklin institute of Philadelphia have been illuminated by means of the light radiated from bare copper wires in the open air carrying these so called Tesla currents.

The wires were not hot, but they radiated from their surface light and sent from one to another bands and streamers of the mysterious light which we see in the aurora borealis. The effect must be seen to be thoroughly appreciated, but when it is stated that the experimenter without difficulty succeeded in radiating light not only from an exhausted glass tube held in his hand, but also from his thumb, his nose and other features, the enthusiasm which swept over his audiences in London and in Philadelphia may be appreciated.

As yet no useful application has been found for these wonderful new developments in electrical science, but they should be welcomed as a harbinger of further progress.--Baltimore Sun.


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