Scranton, PA: International Textbook Co., 1939. First edition. Hard Cover. 12 mo. pp iv, 49. illustrated with engravings. Very Good. Item #247
As with all the Int'l Textbook technical series for Tradesmen, solid, trustworthy and practical studies, wonderfully illustrated. Much of the material in this title was "state-of-the-art" at this time. Uncommon.