A publicity photo of a participant sitting in the Colorado Springs experimental station with his "Magnifying Transmitter". The arcs are about 22 feet (7 m) long. (Tesla's notes identify this as a double exposure.)
At this location, in 1899, Tesla, several of his assistants, and a local contractor commenced the construction of Tesla's laboratory shortly after arriving in Colorado Springs. The lab's primary purpose was to conduct experiments with high frequency electricity and other phenomena. Its secondary purpose was for research into wireless transmission of electrical power. The lab possessed the largest Tesla Coil ever built, 49.25 feet (15 m) in diameter,  which was a preliminary version of the magnifying transmitter planned for installation in the Wardenclyffe Tower. This coil reproduced the effects of lightning and its accompanying thunder for the first time in history. On January 7, 1900, Tesla's lab here was torn down, broken up, and its contents sold to pay debts when Tesla left Colorado Springs.
^The Giles City Directory of Colorado Springs and Manitou(PDF) (almanac). The Giles Directory Company. May 1903. Retrieved 2013-11-02. Cahill F A watchman Tesla Station bds [resides] 1104 E Platte ave ... Tesla Experimental Station, 1 mile east of P O [main post office] via Pike's Peak ave