652 Mr. Nikola Tesla on Alternate Currents, dc. [Feb. 4, 



appeared desirable to produce enorraous potential differences, alter- 

 nating with extreme rapidity. Experiments in this direction led to 

 some of the most interesting results arrived at in the course of these 

 investigations. It was found that by rapid alternations of a high 

 electrostatic potential, exhausted tubes could be lighted at consider- 

 able distance from a conductor connected to a properly constructed 

 coil, and that it was practicable to establish with the coil an alter- 

 nating electrostatic field, acting through the whole extent of a room 

 and lighting a tube, wherever it was placed in the same. Phosphor- 

 escent bulbs may be excited in such a field, and it is easy to regulate 

 the effect by connecting to the bulb a small insulated metal plate. 

 It was likewise possible to maintain a filament or button mounted in 

 a tube at bright incandescence, and in one experiment, a mica vane 

 was spun by the incandescence of a platinum wire. 



It is hoped that the study of these phenomena, and the perfection 

 of the means for obtaining rapidly alternating high potentials, will 

 lead to the production of an efficient illuminant. 



[Nikola Tesla.] 



