Elmer A. Wall, an engineer/inventor of considerable ability, operated a motor car manufacturing company in Chicago before Ford made his Model “T.” He also designed and built an electrical power system supplying part of the city before Consolidated Edison existed. He had many associates in the engineering profession in this country and abroad. During the depression he began designing and manufacturing casting kits for miniature internal combustion engines such as this Duplex Mariner, circa 1940-41. This engine is 9”-long, 6”-wide, and 8”-high.
Wall’s Model Engine Laboratory was located in Chicago, IL and the catalog cover read:
“Build Your Model Internal Combustion Engines with WALL CASTINGS and DETAILED DRAWINGS on your own lathe in your own work shop. Easy to Build and Interesting to Run. Suitable for Model Aircraft and Record-Breaking Model Power Boats. Also… Has it ever occurred to you that in buying these construction sets you are purchasing knowledge which has taken some other man, an expert at his job, a lifetime to acquire?”