Elementary lessons in electricity and magnetism (1906)
Thompson, Silvanus P. (Silvanus Phillips), 1851-1916, Schwetzky, Otto H. L. [from old catalog] · Chicago, Thompson & Thomas · leaf 446
en the sounds in the telephone again cease. It ispossible by this means to test the relative conductivity ofdifferent metals which are introduced into the coils. Itis even possible to detect a counterfeit coin by the indi- 420 ELEMENTARY LESSONS. [chap. xii. cation thus afForded of its… … Fig. 171. 430. Hughes Magnetic Balance.—^A very con-venient instrument for testing the magnetic propertiesof different specimens of iron and steel was devised byHughes in 1884. The sample to be tested is placed ina magnetising coil A (Fig. 171), and a current is sentround it. It deflects a…
Electricity · Magnetism
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