Original vintage magazine ad, A. O. SMITH CORPORATIONof Milwaukee, WI. Oil and Gas Field Products Division. SMITHSTEEL CRACKING STILLS. Pictured is the largest oil cracking still ever built (as of 1928), almost 70 feet long, 10 feet inside diameter, 3 1/2 inches wall thickness, and 366,600 lbs. weight. Old 1928 petroleum advertisement. Would look sensational matted and framed!