29,307. Frey, A. Dec. 31. Incandescent lamps, adapters for, containing thermal switches for the purpose of making and breaking the circuit periodically. The adapter, Fig. 1, is made in two parts, an upper part a similar to the socket, and a lower part c like the cap of an ordinary lamp. The switch l in the lower part c is composed of a bent compound metal strip, usually iron and brass, attached to the pin i, and with a contact-screw n through one end of the strip, a heating-coil o insulated from the strip, and a metal contact-plate m, likewise insulated. When the strip is cold, the end of the screw n is in contact with the plate m, and current passes from one contact-pin g of the lamp through the pin i, bent strip, contact-screw n, contact-plate m, and beating-coil o to a terminal. The bent strip unbends as it grows hot and breaks circuit, which is restored as it coo's down, and a periodic make-and-break is kept up.