Nikola Tesla Books
Jan. 6, 1900
Photographs taken with Mr. Alley from Dec. 17 to Dec. 31, 1899 and particulars relating to the same continued:
LII. This plate shows a discharge from the top of the extra coil, produced by a single closure of the circuit or throw of the switch, of very short duration. The discharge issues again from the brass ring on the top of the extra coil, which is viewed centrally. Some streamers pass into the air and sparks dart to the hood above the coil. A curious spiral or screw motion in one or two streamers is noticeable. The light of the discharge, though lasting but one fraction of a second, is strong enough to reveal a part of the structure and the top of the coil. The current of air separates the sparks and streamers into the individual discharges produced by the break wheel. This effect is beautifully shown. The vibra-
Along with comments on photograph No. 55, Tesla displayed other possible ways of producing bright spots on streamers. He assumed that along current streamers acertain kind of moving standing wave is produced which is made by means of two (or more) waves of different frequencies. He even displayed how two waves of adjacent frequencies could produce parameter variations of the oscillator constants at various operating conitions. Tesla recalls some previous experiments and does not give sufficient explanations to allow the understanding of it all.
Continuing his thinking, he described the future experiments with "tamed'' current streamers in a big glass tube, which would prove the existence of bright spots on the current streamers, along which two waves of close frequencies propagate.