'"V 



LATERAL MOVEMENTS PRODUCED. 107 



the lateral arrows on the sides of the conducting, 

 wires, 234. 



These lateral movements imparted to conducting 

 wires by the vibrations impinging against their 

 sides, produce rotations of electrodes when sup- 

 ported on an axis; as in Fig. 29, where a conducting 

 wire is shown at No. 

 3, as connected with 

 a pivot c, and free to S *\, T 



turn around circular- f 



ly to the several po- 

 sitions indicated by / 

 the dotted lines i v 

 2 4, up to 8, with " ~ 3~~ 

 another conducting- Fis ' 29 ' 

 wire, A B, beneath ; which may be considered as rep- 

 resenting the horizontal terrestrial current from 

 east to west. The small lateral arrows show the 

 resultant rectangular movement of the wire 3, in 

 each of its eight positions relative to A B ; thus the 

 wire c D 3 will be kept revolving about the pivot c. 



To verify the theory that the divergence of 

 electric currents from a central point at right 

 angles to another current (Fig. 29), will produce a 

 revolving motion of the electrode, or conducting 

 body, Faraday placed a watch-crystal filled with 

 mercury within a brass cup and in contact with 

 its rim, which was amalgamated and connected 

 with the screw-cups ; this brass cup was environed 

 by conducting-wires, and an electric circuit ar- 



