Black Swan Voltmeter. Material: metal, glass. Size: 4" x 4 3/4" x 4" Depth. Description: rusty black metal meter; metal label plate on front: "Black Swan Co., Waseca, Minn."; volts gauge under clear glass cover; two screws at back.
Black Swan Company. Waseca Journal, Wednesday, November 24, 1943: William R. Everett's obituary states that after William R. Everett graduated from high school he was the manager of the Black Swan Company, manufacturers of farm electric plants.