82 



ARC LAMPS WITH SMALL CURRENTS [Cn. Ill 



FIG. 43. THE SMALL ARC LAMP OF REICHERT. 



This is arranged in the figure for giving a parallel beam of light from the 

 small condenser; and the mechanism for feeding the carbons can he actuated 

 at a distance by means of a Hooke's joint and rod. 

 The horizontal or positive carbon. 



Clamp for holding the lamp to the upright at any desired height. 

 Milled head of the feeding mechanism for the carbons. 

 Rod extending from the Hooke's joint. 

 e - ?,> f- S- Holders and clamping screws for the carbons. 

 / Terminal points of the carbons where the arc is formed. 

 ra The tube holding the condensing lens. It is cut away on one side to 

 show the carbons. 



k' ' n The condensing lens in the end of the tube. It is at the principal focal 

 distance from the crater and the diverging beam is made parallel; by pulling 

 it to the right the beam will be converging. 



WIRING AND CONNECTING THE ARC LAMP WITH THE HOUSE 



CIRCUIT 



128. Wiring. The wiring is in principle exactly as for the 

 large current arc lamp (fig. 1,2, 45). 



One end of a double, flexible cable of sufficient length (2 meters, 

 6 ft. at least) is connected with a separable attachment plug (fig. 

 49). The two wires near the other end of the cable arc separated 

 for a short distance, and one wire is cut. The cut ends of this wire 



