Antique steampunk vintage brass and porcelain light socket adaptor with a built-in rheostat or dimmer switch to control to brightness of the light bulb. This adaptor screws directly into a standard light socket and takes a standard Mazda or Edison screw base light bulb. The brightness of the bulb is controlled by turning the adaptor side to side with a small pull chain.
This is marked with Wirt Company and a patent date from 1908. The socket still has the original mica insulator in the bottom. This is in nice very nice condition with no chips to the procelain or stress cracks to the brass. The brass has a lovely patina of age.