THE ELECTRIC MACHINE. 



207 



piece, Q, and sustained upon glass supports. At the end of the conductors are 

 two curved rods, CC, which are provided with points to take the electricity 

 from the plate, but do not touch it. 



The electricity is thus stored in the insulated conductors as the machine 

 is turned. The negative portion is carried into the ground by the chain 

 from the rubbers, while the positive electricity is retained. The longer we 

 turn the more we shall obtain, and the quantity is measured by an electric 

 pendulum on one of the conductors, which flies out by degrees as the charge 



Fig. 212. The Electric Machine. 



increases, and indicates its power by means of a needle it works upon an 

 ivory index. 



It is not difficult to make an electric machine out of a glass bottle. 

 This will furnish the glass cylinder. If a stick be run through it (for which 

 purpose a hole must be drilled in the bottom of the bottle), a handle can be 

 fixed, and the bottle mounted on a stand. A wash-leather cushion, stuffed, can 

 be so arranged that it will press against the bottle as it is turned ; a piece of 

 silk should be permitted to hang from the cushion frame over the glass. A 

 conductor may be made from a piece of wood neatly rounded and smoothed, 



