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ELECTRIC LIGHT 



little pulley. For this purpose, it only requires that a counterpoise placed ;it the end 

 of the cord shall bo enabled to be in equilibrio with it. The metal cross piece which 

 occupies the upper part of the apparatus, carries a small brass tube, which descends 

 perpendicularly in front of the carbon that is carried by the electro-magnetic stem, 

 and into which is also introduced a carbon crayon. By means of a very simple ad- 

 justment, this tube may besides be easily regulated, both for its height and for its 



790 



direction ; and consequently the two carbons may be placed very exactly above one 

 another. The apparatus being adjusted, we place one of the two metal columns of 

 the apparatus in connection with one of the poles of the pile, and cause the other 

 pole to abut upon the copper-wire of the bobbin (one end of which is soldered upon 

 its socket). The current then passes from the bobbin to the lower carbon by the rod 

 itself that supports it, and passing over the interval separating the two carbons, it 



