THE ELECTRIC LIGHT. 443 



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 

 towards the improvement both of machines and regu- 

 lators. 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 influ- 

 ence the share market in the slightest degree, I limit 

 myself to this general statement of opinion. 



To one inventor in particular belongs the honour of 

 the idea, and the realisation 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 Eussian officer, 

 M. Jablochkoff. He sets two carbon rods upright at 

 a small distance apart, and fills the space between them 

 with an insulating substance 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 hori- 

 zontally from top to top. This cross-piece is imme- 

 diately dissipated or removed by the current, the passage 

 of which once established is afterwards maintained. 

 The carbons gradually waste, while the substance be- 

 tween them melts like the wax of a candle. The com- 

 parison, however, only holds good for the act of melt- 

 ing; for, as regards the current, the insulating plaster 

 is practically inert. Indeed, as proved by M. Rapieff 

 and Mr. Wilde, the plaster may be dispensed with alto- 

 gether, the current passing from point to point between 

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