256 



VOL TA 1C ELECTRICITY. 



FIG. 201. 



4O7. The Inductive Action of a Temporary 

 Magnet. If within the coil a soft iron bar (or still 

 better, a bundle of straight soft, iron wires) be placed, as 



FIG. 202. 



shown in Fig. 202, the induced current may be more 

 effectively produced by bringing one end of a permanent 



