Original heating trade vintage catalog for DRYING SYSTEMS, INC. was located at 1810 Foster Avenue, Chicago, IL. Manufacturers of Industrial Ovens, Heating and Air Conditioning Equipment. Dryers, external heaters, AC, humidifying and refrigerating equipment. Dry-Sys Air Flow Switch, Racks, Paper Machine Hoods and Conveyors. Disbound from a large 1931 industrial heating catalog, this unique old one page technical brochure would display wonderfully matted and framed. A marvelous addition to your retro heating equipment library. Slight damp stain on outer edge.