CHAPTER VII. 

 ELECTEIC GENERATORS. 



THE ELECTROPHORUS AND FRICTIONAL MACHINE. 



THE only electric generators noticed thus far are the 

 rods of glass, ebonite, and sealing-wax ; rubbed with 

 silk, woolen, or fur: but it is evident, that for such 

 work as the charging of Leyden jars and batteries, and 

 similar experiments, we require generators of far greater 

 capacity. But it was thought best to anticipate their 

 existence, and defer their introduction till there had 

 been a full consideration of the principles on which the 



various kinds de- 

 pend: so that they 

 might all be in- 

 cluded in one com- 

 prehensive view ; 

 from which the 

 merits of each, and 

 Fig. 27-Eiectrophorus. the principles of 



its construction could be more fully ascertained. 



THE ELECTROPHORUS. This instrument, invented 

 by Volta, is one of the simplest forms -of a static gen- 

 erator ; but it is of great utility in furnishing an 

 unfailing, though limited supply of electricity, for 

 numerous delicate experiments. 



The following style, designed by the author, and 

 represented by Fig. 27, makes a handsome, convenient, 

 and very efficient instrument. 



