Original laboratory trade vintage catalog for JAMES G BIDDLE COMPANY. Main office and factory was located at 1211-1213 Arch Street, Philadelphia, PA. Manufacturers of Speed Measuring and Electrical Testing Instruments and Scientific Apparatus. Frahm, Megger, Jagabi Test Equipment. Tachometers, Frequency Meters, Hand Tachometer, Sliding Contact Tube Rheostats, Ground Tester and Water Tester. Disbound from a large 1931 laboratory equipment construction book, this unique old one page technical specifications brochure would display wonderfully matted and framed. A marvelous addition to your retro electric equipment library. Slight damp stain on outer edge.