THE PHENOMENA OF ELECTROSTATICS. 



205 



contact with the metal buttons which project from two of the 

 carriers. The result is that these two carriers become charged 



Fig. 130. 



under the influence of the positive and negative charges on AA 

 and BB, the upper carrier being negatively charged and the 



Fig. 131. 



lower carrier being positively charged. The rotation of the inner 

 cylinder then moves the carriers in the direction of the curved 



