274 SOME NEW MODES OF LIGHTING. 



In all the methods of lighting thus far mentioned in this article 

 the source is a A^ery intense light restricted to a comparatively nar- 

 row area ; but there has very recently been installed in New York 

 a system of elect>ric lighting by vacuum tubes of great length, whose 

 comiDaratively feeble brightness is counterbalanced by their great 

 area of luminous surface. Plate I shows an apj^lication of this 

 method of lighting within an apartment. While not yet fully per- 

 fected, this system gives excellent promise, both as regards clieapness 

 and general satisfactory qualities of illumination. A principal diffi- 

 culty seems to consist in obtaining a suitable gaseous conductor 

 Avliose spectrum shall approximate that of ditfused daylight instead 

 of being restricted to a few wave lengths like that of mercury, but 

 partial success in this respect is already achieved. 



