Tesla's Advance in Vacuum-Tube Illumination

According to the Electrical Review of New York, electrical progress of the new year's auspiciously begun by Inventor Tesla's advance in vacuum-tube illumination. With a tube of a thousand candle-power supplied by an Edison direct-current, and an exposure of from two to five seconds results were obtained that promise to supersede the flash light in photography, and Tesla thinks the method he describes will eventually be employed for lighthouse purposes. The increase of candle-power and of efficiency has been achieved by "gradual perfection of the means of producing economically harmonical electrical vibrations of extreme rapidity," and these amounted to about two million a second in the tube experimented with.