Original electrical trade vintage catalog for MUTUAL ELECTRIC MACHINE COMPANY, was located in Detroit, MI. Manufacturers of Electrical Controlling Devices. Bull Dog knife switches, switchboards, panelboards and cabinets with Underwriters' approval. Model DF-7 dead face theater switchboard, white carrara glass switchboard are pictured. Disbound from a large 1916 electrical construction materials book, this unique old one page technical brochure would display wonderfully matted and framed. A marvelous addition to your retro electric equipment library. Contains a small amount of residual glue on edge.