Image: Tesla lab coil1

Description: An early Tesla coil constructed by Nikola Tesla at his laboratory at 35 South Fifth Ave., New York around 1895. The voltage produced at the top terminal of the conical secondary coil may have been several hundred thousand volts, at a frequency around 1 MHz, producing a purple brush discharge, which is slightly exaggerated in this time exposure. At left are glass plate capacitors that formed the tuned circuit with the primary of the coil. Caption: TESLA COIL FOR ASCERTAINING AND DISCHARGING THE ELECTRICITY OF THE EARTH. THE STREAMERS AT TOP ARE OF PURPLE HUE, AND IN FORM RESEMBLE FILAMENTS OF SEAWEED, THE EFFECT OF MASS BEING CAUSED BY PROLONGED EXPOSURE OF FLASH-LIGHT NEGATIVE
Title: Tesla lab coil1
Credit: Thomas Commerford Martin, "Tesla's Oscillator and Other Invetions" in Century Magazine, The Century Co., New York, Vol. 49, No. 6, April 1895, p. 932, fig. 15
Author: Thomas Commerford Martin. The accompanying article (p. 916) says photos were taken by Tonnele and Co.
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License: CC-BY-SA-3.0
License Link: http://creativecommons.org/licenses/by-sa/3.0/
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