Controller from an old tram, possible Tram 22. Appears to be a typical parallel drum controller with the casing removed. The arc shield is in place. With this swung back the drum segments and fingers are revealed. The controller is supplied with power via a current limiting automatic circuit breaker. It has a handle on top and this turns a drum fitted with insulated copper segments. There is usually a star wheel and roller which ensures that the drum advances in notches to match the drum segments.Large laminated photograph of a tram controller c1920controller, tramcars, parallel drum controller, automatic circuit breaker, handle, star wheel