Note 30 — ON SOME MARVELS IN TELEGRAPHY.

I must caution the reader against Fig. 348 in Guillemin’s Application of the Physical Forces, in which the part c d of the wire is not shown. The two coils are in reality part of a single coil, divided into two to permit of the bar being bent; and to remove the part c d is to divide the wire, and, of course, break the current. It will be seen that c d passes from the remote side of coil b c, Fig. 6, to the near side of coil d e. If it were taken round the remote side of the latter coil, the current along this would neutralize the effect of the current along the other.