Davis's manual of magnetism : including galvanism, magnetism, electro-magnetism, electro-dynamics, magneto-electricity, and thermo-electricity (1854)
Davis, Daniel · Boston : Palmer and Hall · leaf 228
REVOLVING ELEGTRO—MAGNET. 211 f\>. 145. … either side, and is interrupted while it is recedingfrom them. A continuous vibration is thus occa-sioned, which imparts motion to a fly-wheel, and toa hammer, which strikes the bell seen in the cut. 335. Fig. 145 represents another form of the in-strument, in whichthe axis of motionof the armature…
