2O2 



ELECTRIC LIGHTING. 



current, intense enough to make this portion incandescent. The 

 current enters or leaves through the contact /, and it leaves or 

 enters through the contact B. The contact /, which is elastic, 

 presses the rod laterally; the contact E touches it endways. 

 Under these conditions, the carbon wastes at its extremity j 

 quicker than at any other place, and tends to become shorter. 

 Consequently, if the carbon C is continually pushed in the direc- 

 tion of the arrow so as to always press on the end contact B, it 

 will advance gradually as it is consumed by sliding in the lateral 

 contact /. The heat developed by the passage of the current in 

 the rod is greatly increased by the combustion of the carbon. 



FIG. 52. 



FIG. 53. 



" In practice, I replace the fixed contact by an end contact P., 

 Fig. 53, which removes the ashes of the carbon. The rotation 

 of the end contact is concomitant with the progressive move- 

 ment of the carbon rod, so that the position of the latter on the 

 end contact acts as a brake on the moving mechanism. 



" The principle of this new system of lamp having been esta- 

 blished, it was easy to invent simpler arrangements for carrying 

 it out. The samples which I have the honour of laying before 

 the Society will explain themselves at a glance. The progression 

 of the carbon c and the rotation of the end contact B are obtained 

 by the descent of the heavy rod of the carbon-holder.* To wind 

 up the lamp, this rod has merely to be lifted up. The rod of 



* Comparative experiments made by Reynier prove that the renewal of 

 the end contact is indispensable for obtaining a somewhat prolonged action 

 with the ordinary carbons of commerce. 



