268 



SCIENTIFIC RECREATIONS. 



of Mr. Edison. The early career of that American " magician " is now 

 tolerably well known ; his tremendous energy and application are fully 

 appreciated. With only a few months schooling all -his life he has taken a 

 foremost place in the scientific world. In ten years he has in- 

 vented the phonograph, the electric pen, a system of fast telegraphy, 

 the electro-motograph, the telephone, a tasimeter, and other useful 

 applications of electricity, besides solving the problem of electric light 

 for domestic purposes. 



Mr. Edison's electric light * requires something more than a 

 passing notice, and we will therefore endeavour to give a sketch of 

 the general subject. Now that the electric light has been made 

 .. fl available for domestic purposes, and the very simple lamp (consisting 

 IJi' of an exhausted glass globe, two platinum wires, and a piece of 

 * charred paper) can be obtained, people will no doubt soon largely 

 adopt electric lighting in their houses. The light has found a success 

 at the theatre, in the streets, and in the train ; there is no reason 

 why it should not be adopted generally, being more economical and 

 |c more healthy than gas. 



If we sever an electric wire, and bring the ends, tipped with 

 EfctSIc' carbon, into juxtap osition, we obtain a brilliant light. This is the 

 candle> Voltaic arc we have already mentioned, produced by the incandescence 

 of finely-divided matter; it was the first method of illuminating by electricity, 

 and was discovered by Sir Humphrey Davy, who obtained a very brilliant 

 light, but at great expense about a guinea a minute ! 

 But the Daniell and Grove batteries and generators, and 

 modern improvements in 1860, brought the use of the 

 electric light into prominence. Faraday lighted a light- 

 house with its assistance. 



But when the GRAMME GENERATOR was invented the 

 needed impetus was applied. The JablochkofT candles 

 followed, and now we have the electric light in full operation. 

 So far we have sketched the history of illumination by the 

 Voltaic arc, and descriptions of the various apparatus will be 

 found at the end of this chapter. But the method of lighting 

 with an incandescent solid was introduced in 1845 by Starr 

 and Peabody, who took out a patent for the use of platinum. 

 Later on Drs. Draper and Despretz made experiments with 

 platinum and carbon. The latter gentleman sealed the 

 carbon in an exhausted globe, and then introduced nitrogen 

 in place of the air. But the method died out and was for- 

 gotten, and in 1873 a medal was actually given by the Academy of 

 St. Petersburg for the " discovery " to Messrs. Sawyer and Mann. 



In 1878 Paris was lighted with the electric candles of Jablochkoff. 



* We are indebted for many facts respecting Mr. Edison's light in this chapter to a 

 paper by Mr. Upton. 



Fig. 272. Chandelier. 



