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 129
s curved forwards or backwards, according tothe course of the current; in either case, tending tomove away from between the magnetic poles in alateral direction. The motion depends on the samecause as that of the wire in the instrument describedin <§. 177. This instrument does not indicate… … REVOLVING SPUR—WHEEL. 113 ing movement in the instrument described in <5.177may be converted into one of rotation, by making Fig. 64. use of a copper wheel, thecircumference of which iscut into rays, instead of thewire. The points of thewheel, W (Pig. 64,) dip in-to mercury contained in asmall…
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