THE BANISHMENT OF NIGHT 



lamp, though not yet adapted to all the purposes served 

 by the Edison lamp, on account of its peculiar color, 

 produces eight times as much light with the same 

 amount of power. It is also practically indestructible, 

 there being no filament to burn out; and it requires 

 no special wiring. By means of this invention electricity, 

 instead of being the most costly means of illumination 

 becomes the cheapest cheaper even than kerosene. 

 No further explanation than this is necessary to show 

 the enormous importance of this invention." 



As just stated, the defect of the Edison incandescent 

 lamp is its cost, due to its utilizing only a small fraction 

 of the power used in producing the incandescence, and, 

 of much less importance, the relatively short life of 

 the filament itself. Only about three per cent, of the 

 actual power is utilized by the light, the remaining 

 ninety-seven per cent, being absolutely wasted; and 

 it was this enormous waste of energy that first at- 

 tracted the attention of Mr. Hewitt, and led him to direct 

 his energies to finding a substitute that would be more 

 economical. A large part of the waste in the Edison 

 bulb is known to be due to the conversion of the energy 

 into useless heat, instead of light, as shown by the heated 

 glass. Mr. Hewitt attempted to produce a light that 

 would use up the power in light alone to produce a 

 cool light, in short. 



Instead of directing his efforts to the solids, Mr. 

 Hewitt turned his attention to gaseous bodies, believing 

 that an incandescent gas would prove the more nearly 

 ideal substance for a cool light. The field of the pas- 

 sage of electricity through gases was by no means a 



[ 2 37] 



