ELECTRIC GENERATORS. 117 



inductive influence; and the plate B is supported on two 

 insulators, while the upper half has but one, and hence 

 has the advantage of the better insulation of the air. 



To this lower half of B, and subject to these influ- 

 ences, is attached the brush holder F, while E is 

 attached to the upper half, and remote from them. 

 Hence, the carriers brushed by E, and descending to- 

 wards L, must acquire a higher potential than those 

 brushed by F, and ascending towards K. 



An accumulation of electricity must also occur at the 

 lower ends of the inductors ^and X, from the induct- 

 ive influence of the earth ; and as the brush holder F 

 is placed at the lower end of X, it furnishes an outlet 

 to a portion of this charge, as seen at night by the 

 brushes of light from this holder to the outside of the 

 jar (7, and other parts in close proximity. 



The lower end of T, on the contrary, is well insu- 

 lated ; hence the potential of T, from the heavier charge 

 at its upper end, and the better insulation at its lower 

 end, must be much higher than that of X, where the 

 influences are just the reverse. 



This accumulation, or high positive potential at the 

 lower end of T, produces a high negative potential at 

 that point on the plate A, and its carriers, as it revolves ; 

 as shown by the brush of light, seen in the dark, from 

 the uninsulated comb F, marking the flow of electricity 

 to the upper part of the plate, as it passes under that 

 comb; the outflow of the current received through the 

 comb H. This brush of light extends downward, as 

 the charge increases, almost to the comb K: and a sim- 

 ilar brush extends downward from K, marking the 

 outflow of electricity from the interior of the jar (7, as 

 explained hereafter: while the points of the combs, L 



