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 201
erted by helices on either straight or bentbars of iron. 295. Electro-Magnet. — A bar of iron, woundwith insulated wire, so as to be enclosed in a he^lix, is termed an Electro-Magnet.During the passage of an electriccurrent along the wire, the barexhibits a remarkable degree ofmagnetic power, far… … ELECTRO-MAGNET, IN FRAME. 185 For the purpose of showing its lifting power, theelectro-magnet is made of the 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,…
