274 SOME NEW MODES OF LIGHTING. 



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

 the source is a very intense light restricted to a comparatively nar- 

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

 a system of electric lighting by vacuum tubes of great length, whose 

 comparatively feeble brightness is counterbalanced by their great 

 area of luminous surface. Plate I shows an application of this 

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

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

 and general satisfactory qualities of illumination. A principal diffi- 

 culty seems to consist in obtaining a suitable gaseous conductor 

 Avhose spectrum shall apjjroximate that of diffused daylight instead 

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

 partial success in this respect is already achieved. 



