CURRENTS AND MAGNETS COMBINED. 



121 



about the pole of a magnet in conformity with the 

 tangential forces of the circulating currents, as 

 shown in Fig. 40 ; which represents a conducting- 

 wire suspended on a loop, transmitting a current 

 to the mercury in a glass, in which a magnet 

 is inserted, with a connection of its lower end 

 with a coriducting-wire, d, to complete the circuit. 

 The suspended wire revolves about the upper end 

 of the magnet. If the wire be extended the whole 

 length of the magnet, the 

 diamagnetic currents neu- 

 tralize this action. 



He afterward succeeded 

 in producing the recipro- 

 cal revolutions of a mag- 

 net, M, and conducting- 

 wire w, about one another, 

 as represented in Fig. 41. 

 Mercury was used in the 

 glass for a conductor in 

 connection with the screw 

 cup c. 



Innumerable other com- Fie- 41. 



binations of currents and magnets have been 

 invented to illustrate the transmission of electro- 

 mechanical action. Although the principal mag- 

 netic power is manifested by the poles, or ends, 

 of magnets, yet a very important action is devel- 

 oped by the currents circulating about the mid- 

 dle or equatorial parts, as previously illustrated 



