92 PROCEEDINGS OF THE CANADIAN INSTITUTE. 



BBB are strips of brass, pivoted at the lower end, each of which can make 

 contact with two of the studs, represented by heavy dots in the diagram ; 

 E are feed wires from the incandescent circuit ; and the dotted lines represent 

 the invisible connections. 



These various parts may be conveniently mounted on a board eighteen by 

 eight inches. 



By combining the lamps in different ways, currents varying from 0.2 to 

 2 amperes may be obtained, a range which is ample for the usual electroly- 

 tical work. 



