622 ELECTRICAL ENGINEERING 



of defying the most stubborn attacks of the elements, but they are, 

 of course, expensive, and the question arises whether a trunk line, 

 say, between New York City and Philadelphia, equipped for heavy 

 electrical traction in accordance with the most approved methods, 

 so as to secure a rapid transportation of even the heaviest loads 

 in large units as well as in small units at frequent intervals and 

 with perfect security of the continuity of service, it is a ques- 

 tion, I say, whether such a solution of the problem before us is 

 a financially attractive proposition. 



There is a strong belief among the progressive members of the 

 engineering profession that the question will be answered in the 

 affirmative in the very near future. 



The Electric Lighting Problem 



The efficiency of the electrical arc-lamp is satisfactory; its mech- 

 anism is somewhat complex, and the sharp shadows produced by 

 a powerful source of light concentrated in a very small volume are 

 objectionable, not to mention the physiological effect upon the eyes 

 of an intense source of this kind. On the whole, however, this form 

 of electric lighting is considered as highly efficient and effective 

 although not quite so cheap as some of the modern chemical methods 

 of light-generation. Electric lighting by incandescent filaments is the 

 field in which the public is awaiting marked improvements. This is 

 the form in which lighting by electricity is distributed in small units. 

 It is ideal in its simplicity and convenience, but it is a luxury in which 

 the rich, only, can indulge; it is too expensive. The so-called fine 

 arts are aristocratic ; science and the technical arts are nothing if 

 not democratic. The fruits of their labor must be within reach of 

 everybody; if not, the soil which bears any particular one of these 

 fruits will not be sufficiently cultivated by the public and it will soon 

 become a hothouse product of the rich or cease altogether. To 

 transform incandescent electric lighting into a democratic institu- 

 tion is one of the electrical engineering problems of to-day. Its 

 solution involved many problems in the economy of generation and 

 distribution of electric power, all of which have been satisfactorily 

 solved by the electrical engineer, so that the main solution has 

 converged finally to the following proposition : To find a substance 

 which will have a sufficiently high resistance, will stand a higher 

 temperature than the carbon filament without too rapid deteriora- 

 tion, and the radiation of which at this high temperature will be rich 

 in visible waves. Osmium, tantalum, and some other refractive rare 

 metals have been tried and seem to promise well. But in many re- 

 spects the most satisfactory results have been obtained by Peter 

 Cooper Hewitt with his mercury vapor lamp. The efficiency of this 



