ELECTRICAL APPARATUS. 

 Fig. 271. 



253 



on the cushion about a quarter of an inch from the upper 

 edge ; it extends over the upper surface of the glass cylinder 

 to within an inch of a row of metallic points, proceeding like 

 the teeth of a rake from a horizontal rod, which is fixed to 

 the adjacent side of the opposite conductor. The motion is 

 given by a simple handle formerly a multiplying wheel 

 was used, but it has many disadvantages and is more labori- 

 ous. The conductors are usually made of metal, japaned 

 black, perforations being made at the ends and on the top 



