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 188
speak of it as magnetic, and to give the names ofnorth and south poles to the extremities of its axis. 274. In Fig. Ill are represented, at a a, twodouble cylinders of iron, enclosing a coil. A sec- Fig, 111. … tional view of one of them isgiven separately at A. It con-tains a cavity in the form of ahollow cylinder, adapted to re-ceive one half of the coil seenat C, the remaining half pass-ing into the other cylinderwhen they are fitted together.A longitudinal opening on oneside of the cylinders allowsthe…
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