INCANDESCENT LAMPS. 195 



INCANDESCENT LAMPS. 



The interesting experiments undertaken by Lodyguine 

 and Kosloff prompted several inventors to contrive lamps 

 for obtaining the electric light 'by the incandescence of the 

 carbons. It seems, however, according to Fontaine, that 

 King, as early as 1845, nac ^ invented the first lamp of that 

 kind.* 



King's and Lodyguine's Lamps. King's lamp consists 

 of a slender rod of retort carbon fixed at its ends into two 

 carbon cubes, and supported by a stand with two porcelain 

 arms. The whole is enclosed in an exhausted tube, and the 

 rigid conductors traversing this tube interpose the little car- 

 bon rod in the circuit of the electric generator, by which it 

 is made to glow sufficiently to give a brilliant light. This 

 is, it will be seen, a system somewhat resembling that of 

 Lodyguine and Kosloff, mentioned on page 144. 



This idea was taken up in 1846 by Greener and Staite, 

 and in 1849 by Petrie. "Illumination by incandescence," 

 says Fontaine, " and the principle of its production, had long 

 been forgotten, when, in 1873, a Russian physicist, Lody- 

 guine, resuscitated both, and made a small lamp, which was 

 subsequently improved by Konn and Bouliguine. 



In his lamp Lodyguine used carbons in one piece, diminish- 

 ing the section at the luminous centre, and in the same 

 apparatus he placed another carbon, through which, by means 

 of a commutator, the current could be sent when the first 

 carbon was consumed. Kosloff, who came to France ex- 

 pecting to work Lodyguine's patent, effected some little im- 

 provement in this lamp, without, however, getting at anything 



* It is stated that this lamp was invented by J. W. Starr. (Sec the 

 Telegraphic Journal < the ist January, 1879, p. 7 and 15.) 



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