MOTIVE-POWER REQUIRED. 57 



carbon points, and also the use of a circuit of fine 

 wires for developing, by their molecular vibrations, 

 the excitation transmitted through them, in the 

 phenomenon of incandescence. But these molec- 

 ular vibrations disintegrate the wires and render 

 them liquid, or aeriform, and incapable of use. If 

 the intensity of the electric excitation by magneto- 

 electric machines were equal to that excited by 

 rotated inductive machines, this difficulty would 

 have been obviated, as the latter transmit flashes 

 through a foot or two of space. The difference 

 between the extent of motive-power requisite to 

 operate a magneto-electric machine and a Holtz 

 inductive machine, is about inversely as the length 

 of the electric sparks produced by them. A 

 very slight motive-power operates the inductive 

 machine, while several horse-power is requisite 

 to operate magneto-electric machines. A great 

 amount of mechanical force is necessary to put 

 the electric ether in motion at the instant the 

 wires are connected to make the circuit. 



This impressive fact affords evidence of the 

 conversion of mechanical action into light and 

 heat, and also of the transmission of motive -power 

 by electric ether with its high velocity, and af- 

 fords a prospect of utilizing the electric medium 

 by conducting wires, as a substitute for bands and 

 shafts in operating machinery at a distance. 



The question of cost and conveniency of excit- 

 ing electric light, not of its efficiency, must event- 



