Nikola Tesla Books
[Sec. 6., cont.) detectable signals at a distance of 1,000 km.' I have read many Tesla's papers, notes and statements about Colorado Springs experiments, but I have never found in them something that would support '26 miles claim.'"
One would have expected to find such a climactic test described in the CSN. The closest item that this writer has been able to find alluding to such a test appeared in the February 1919 issue of Electrical Experimenter, page 726 (Appendix C). In answer to a question from a reader, the editor replied that "...Nikola Tesla has successfully lighted lamps and operated motors by the one wire and no-wire wireless system for distances of 15 miles in his famous Colorado experiments..." Although it may be assumed that the response for this may have been based on a discussion with Tesla, it would have gained credibility if the editor would have so said.
7. Schumann resonances
Dr. Wait, in a marginal note to this writer on an offprint of his paper "Propagation of ELF Electromagnetic Waves and Project Sanguine/Seafarer" (IEEE Journal of Oceanic Engineering, April 1977, pp. 161-172, observed that "Tesla was probably the first to produce ELF waves of sufficient strength to tickle Schumann resonances." Clearly, such a mode of generating standing waves in the earth was not entertained by Tesla. He was aware of the cavity, which we in recent years refer to as the "Schumann cavity," but he used it as an argument against the efficacy of Hertzian straight-line propagation in that electromagnetic waves would be expended because of innumerable reflections between the earth's surface and the ionosphere. However, this writer fully recognizes that whatever the propagation mode Tesla may have visualized, even though incorrect by today's understanding, such would not invalidate a patent for apparatus accomplishing the desired result.
The Schumann cavity resonance modes are few and occur at ELF values. The first five prominent resonance modes observed in a noise power spectrum, rapidly decreasing in strength as the maxima peaks increase in frequency, are:
7.5, 14.5, 20.0, 27.5, and 31.5 Hz.
See, for example, Terrestrial Propagation of Long Electromagnetic Waves, Janis Galejs, Pergammon Press, Oxford, 1972, cited at page 265. Although decimal-accuracy figures are given, it should be noted these resonances are averages. The resonance values shift somewhat and change in spectral distribution from day to day due the irregularities and movement of the cavity conducting surfaces.
James Corum and A-Hamid Aidinejad have made an interesting analysis of the 0.08484 figure in their paper, "The Transient Propagation of ELF Pulses in the Earth-Ionosphere Cavity," presented at the 1986 International Tesla Society Symposium and published in its Proceedings. They offer that the time interval
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