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 202
he U form, (Fig. 126.)The battery with which it is used should be in pro-portion to the length and fineness of the wire, inorder to obtain the greatest power. With a thickand rather short wire, a battery of one or two pairswill be preferable. With a long and fine wire, anumber of pairs should be… … represents an electro-magnet, fixed in a frame, for tho16* 186 DAVISS MANUAL. purpose of supporting heavy weights. The arma-ture, Aj consists of a semicircular piece of iron.With the e.ectro-magnet, this form is preferable to astraight bar. If the iron of the magnet is soft andpure, its magnetic…
