Mr. G. Fuller on a small Electrical Machine. 



109 



say, negative electricity having been given to the insulated 

 arm m when in a vertical position, on motion being given to 



the machine this electricity is distributed by means of the 

 points over the face of the vulcanite next to B ; at the same 

 time positive electricity is drawn from the earth, thrown upon 

 the other face of that plate by the uninsulated points attached 

 to n. When now B and B / are brought into contact with A, 

 the negative electricity on its one face attracts the positive on 

 the conductor B and repels the negative, whilst the positive on 

 its opposite face attracts the negative on the conductor B' and 

 repels the positive ; then, by means of the piece of tinfoil (r) that 

 connects B and B' when they are in contact with A, the two 

 electricities that are repelled neutralize each other ; and when 

 the plates are moved away from the vulcanite, B is charged 

 with positive and B' with negative electricity. Then, before 



