MAGNETIC INDUCTION PKODUCED BY GALVANISM. 211 



In Figure 68, the properties of Figures 64 and 67 



Fig. 68. 



are combined, and the red end is thrown from the 

 reader with doubled energy. In Figure 69, the action 



Fig. 69. 



is multiplied to any extent. This is the construction 

 of the ordinary galvanometer, and also that of the 

 acting part in the common English speaking-telegraph. 



89. Inductive magnetic power of the galvanic cur- 

 rent: its action on steel and on iron; formation of trans- 

 ient magnets ; registering-telegraphs. 



In treating of pure magnetism we have seen that a 

 magnet-pole, which attracts the red end of a magnetized 

 needle, possesses the power also, in the operation of 

 double-touch, of drawing all the red magnetism of an 



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