CHAPTER VIII, 

 ELECTRIC GENERATORS. 



THE HOLTZ AND TOPLER MACHINES. 



INFLUENCE MACHINES. Previous to 1865, frictional 

 machines were the principal electro - static generators 

 in use. But that year marked an era in electric prog- 

 ress by the invention of two new machines of remark- 

 able energy, by the German electricians, Holtz and 

 Topler; to which the name influence machines was 

 given, from their being constructed with two or more 

 glass plates, arranged to generate electricity by their 

 mutual inductive influence. 



Both machines are very similar in construction ; the 

 principal difference being, that the Holtz requires to be 

 incited by an initial charge from an external source, 

 while the Topler is self-inciting. 



THE HOLTZ MACHINE. This machine, of which 

 there are several different styles, is represented by Fig. 

 36. On a wooden base are mounted two glass plates ; 

 the rear plate B stationary, and supported by three 

 ebonite insulators, two below and one above ; while the 

 front plate A revolves in the direction of the arrow, 

 on a steel shaft, which passes through an opening in 

 the center of the plate B, and is attached to the post 

 at M. A is mounted on an ebonite hub, attached to a 

 hollow shaft of brass, which revolves on the fixed shaft, 

 and carries, at the end next the post, a small pulley, 

 from which a belt extends to the driving wheel, which 



