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 21
y magnetic influence, but immediately losesthis magnetism when that influence is withdrawn.But steel, which is a compound of iron with a smallquantity of carbon, and especially hardened cast-steel, though it acquires the magnetic properties lessreadily, retains them more or less permanently… … Fig. 1. Fig. 1 represents a small case, con-taining two barmagnets, with twoshort pieces of softiron connectingtheir poles: theseact as armatures (see <§» 9), and serve to preservethe power of the magnets. The magnets, when notin use, should be kept packed in the case, with theiropposite poles…
