THE ELECTRIC LIGHT. 679 



into a circuit traversed by a current of only moderate 

 electro-motive power. M. Keynier is also the inventor of 

 a very beautiful little lamp, in which the point of a thin 

 carbon rod, properly adjusted, is caused to touch the cir- 

 cumference of a carbon wheel which rotates underneath 

 the point. The light is developed at the place of contact 

 of rod and wheel. One of the last steps, though I am 

 informed not quite the last, in the improvement of 

 regulators is this: The positive carbon wastes more pro- 

 fusely than the negative, and this is alleged to be due to 

 the greater heat of the former. It occurred to Mr. 

 William Siemens to chill the negative artificially, with the 

 view of diminishing or wholly preventing its waste. This 

 he accomplishes by making the negative pole a hollow cone 

 of copper, and by ingeniously discharging a small jet of 

 cold water against the interior of the cone. His negative 

 copper is thus caused to remain fixed in space, for it is not 

 dissipated, the positive carbon only needing control. I 

 have seen this lamp in action, and can bear witness to its 

 success. 



I might go on to other inventions, achieved or pro- 

 jected. Indeed, there is something bewildering in the recent 

 rush of constructive talent into this domain of applied 

 electricity. The question and its prospects are modified 

 from day to day, a steady advance being made toward the 

 improvement both of machines and regulators. With 

 regard to our public lighting, I strongly lean to the opinion 

 that the electric light will at no distant day triumph over 

 gas. I am not so sure that it will do so in our private 

 houses. As, however, I am anxious to avoid dropping a 

 word here that could influence the share market in the 

 slightest degree, I limit myself to this general statement of 

 opinion. 



To one inventor in particular belongs the honor of the 

 idea, and the realization of the idea, of causing the carbon 

 rods to burn away like a candle. It is needless to say that 

 I here refer to the young Kussian officer, M. Jablochkoff. 

 He sets two carbon rods upright at a small distance apart, 

 and fills the space between them with an insulating sub- 

 stance like plaster of Paris. The carbon rods are fixed in 

 metallic holders. A momentary contact is established 

 between the two carbons by a little cross-piece of the same 

 substance placed horizontally from top to top. This cross- 



