The arc rods within enclosed-type arc lights required replacement every seven to ten days. While the fixture was at ground level the glass globe was cleaned or replaced if defective. Very typically arc lights were lowered for maintenance via a winch and rope mechanism. Some of these lights were mounted on a long mast arm; others on a span wire over the street. Either way, a winch on its connecting pole allowed easy fixture lowering and raising for servicing. The fixture you see was made by the Adams-Bagnell.