3d 



Smithsonian miscellaneous collections vol. 'j^ 



RUSSIAN INCANDESCENT LAMP INVENTORS 



In 1872 Lodyguine, a Russian scientist, made an incandescent lamp 

 consisting of a " V " shaped piece of graphite for a burner, which 

 operated in nitrogen gas. He Hghted the Admiralty Dockyard at 

 St. Petersburg with about two hundred of these lamps. In 1872 

 the Russian Academy of Sciences awarded him a prize of 50,000 

 rubles (a lot of real money at that time) for his invention. A com- 

 pany with a capital of 200,000 rubles (then equal to about $100,000) 



Lodyguine's Incandescent 

 Lamp, 1872. 



The burner was made of 

 graphite and operated in nitro- 

 gen gas. 



Konn's Incandescent Lamp, 



1875. 



In this lamp the graphite rods 



operated in a vacuum. 



was formed but as the lamp was so expensive to operate and had such 

 a short life, about twelve hours, the project failed. 



Kosloff, another Russian, in 1875 patented a graphite in nitrogen 

 incandescent lamp, which had several graphite rods for burners, so 

 arranged that when one failed another was automatically connected. 

 Konn, also a Russian, made a lamp similar to Kosloff's except that 

 the graphite rods operated in a vacuum. Bouliguine, another Russian, 

 in 1876 made an incandescent lamp having a long graphite rod, only 



