Page:Incandescent electric lighting- A practical description of the Edison system.djvu/80

 any reason, the strip of alloy is melted by an excess of current.

When the plugs are screwed into the sockets in the cut-out, their metal button makes contact with the metal button of the socket, while the screw shell arranged on their outside fits closely into the screw shell of the socket, thus allowing the line-wires connected to the cut-

. 23.

out to communicate with each other through the fusible piece contained inside of the plug. Farther on in the house where wires branch off from the main circuit into the several rooms, cut-outs like that shown in Fig. 23 are used, the three wires of the main circuit passing along them in the slots between the sockets, secured therein and connected