American telegraphy and encyclopedia of the telegraph; systems, apparatus, operation (1909)
Maver, William, jr. [from old catalog] · New York, Maver publishing company · leaf 220
For instance, if, as in Fig. 147, the current circulates around the core from lefttonight, as indicated by the arrows, the left hand end will be a north pole and the FIG. 148, … right end a south pole. If from right to left, as in Fig. 148, the right hand end willbe a north pole and the left a south pole. This will be the case regardless of theshape of the core. {See Polarity of Electro-magnets, page 201). It is known that the north pole of one magnet will attract the…
Telegraph
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