Fig. 187.—Detail of the Toy Shocking Machine.
The shocking machine consists of an induction-coil, an interrupter, and a pair of handles, all of which are easy for a boy to make, and a wet or dry battery of one or two cells to furnish the current.
Figs. 188-191.—Details of Induction-coil.
The Induction-coil is the first part to make. This is shown in detail in [Figs. 188] to [191]. The coil has windings of two sizes of wire upon an iron core. For the core buy a 5/16-inch carriage-bolt 2½ inches long, and for the wire coils get some No. 20- or 24-gauge electric-bell insulated copper wire, and some No. 30-gauge insulated magnet-wire. To keep the wire from slipping off the ends of the bolt core, cut two cardboard ends about 1½ inches in diameter. Slip one of these on to the bolt next to the head, and the other one next to the nut, as shown in [Fig. 188].