[Fig. 32.—Magnetic phantom formed by a wire carrying current.]
[Fig. 33.—Magnetic phantom formed by a coil of wire carrying current.]
[Fig. 34.—Diagram of induction coil.]
[Fig. 35.—Induction coil for wireless telegraph purposes.]
[Fig. 36.—Induction coil primary and secondary.]
[Fig. 37.—Interrupter for induction coil.]
[Fig. 38.—Electrolytic interrupter.]
[Fig. 39.—Open and closed core transformers.]
[Fig. 40.—Lines representing direct and intermittent direct currents.]