Nikola Tesla: Colorado Springs Notes, 1899-1900 Page 17

According to his notes, Tesla devoted the greatest proportion of his time (about 56%) to the transmitter, i.e. the high-power HF generator, about 21% to developing receivers for small signals, about 16% to measuring the capacity of the vertical antenna, and about 6% to miscellaneous other research. He developed a large HF oscillator with three oscillatory circuits with which he generated voltages of the order of 10 million volts. He tried out various modifications of the reciever with one or two coherers and special preexcitation circuits. He made measurements of the electromagnetic radiations generated by natural electrical discharges, developed radio measurement methods, and worked on the design of modulators, shunt-fed antennas, etc.

The last few days covered by the diary Tesla devoted to photographing the laboratory inside and out. He describes 63 photographs in all, most of them showing the large oscillator in action with masses of streamers emerging from the outer windings of the secondary and the “extra coil”. He probably derived special satisfaction from observing his artificial lightning, now a hundred times longer than the small sparks produced by his first oscillator in the Grand Street Laboratory in New York. By then many leading scientists had been experimenting with “Tesla” currents but Tesla himself was still in the vanguard with new and unexpected results. When he finally finished his work in Colorado Springs he published some photographs of the oscillator in a blaze of streamers causing as much astonishment as had those from his famous lectures in the USA, England and France in 1891 - 1893. The famous German scientist Slaby wrote that the apparatuses of other radio experimenters were mere toys in comparison with Tesla’s in Colorado Springs.

The descriptions of the photographs in the diary also include detailed explanations of the circuitry and the operating conditions of the oscillator. The photographs themselves give an impressive picture of the scale of these experiments. Tesla maintains that bright patches on some of the photographs were a consequence of artificially generated fireballs. He also put forward a theory to explain this, still today somewhat enigmatic phenomenon. Research on fireballs was not envisaged in his Colorado Springs work plan, but belonged to the special experiments which, in his own words, “were of an interest, purely scientific, at that time”⁽⁶⁸⁾, which he carried out when he could spare the time.

Tesla used some parts of the diary in drawing up the patent applications which he filed between 1899 and 1902. Keeping such notes of his work was more a less a constant practice; they provided him with an aide-mémoire when preparing to publish his discoveries.

The diary includes some descriptions of nature, mostly the surroundings of the laboratory and some meteorological phenomena, but only with the intention of bringing out certain facts of relevance to his current or planned research.

Immediately after he finished work at Colorado Springs Tesla wrote a long article entitled “The problem of increasing human energy” in which he often mentions his results from Colorado Springs⁽⁴¹⁾. In 1902 he described how he worked on this article⁽⁶⁸⁾: “The Century” began to press me very hard for completing the article which I have promised to them, and the text of this article required all my energies. I knew that the article would pass into history as I brought, for the first time, results before the world which were far beyond anything that was attempted before, either by myself or others”.

The article really did create a sensation, and was reprinted and cited many times. The style he uses in describing Colorado Springs research differs greatly from that of the diary.

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