THE ELECTEIC LIGHT. 443 



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 

 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 in- 

 fluence 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 up- 

 right 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 horizontally from top to top. This cross-piece 

 is immediately dissipated or removed by the current, 

 the passage of which once established is afterwards main- 

 tained. The carbons gradually waste, while the sub- 

 stance between them melts like the wax of a candle. 

 The comparison, however, only holds good for the act 

 of melting ; 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 altogether, the current passing from point to point 

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