Original heating industry vintage catalog for HYDROTHERM, INC. Main office and factory was located Northvale, NJ. Manufacturers of gas boiler for the home supplies hot water and heat. Also used in apartments, schools, hospitals, churches, motels, commerce and industry. Operating principles, construction and operation features, single and dual installations, capacity range, applications given. Disbound from a large 1956 home builders heating catalog, this unique old four page technical brochure would display wonderfully matted and framed. A marvelous addition to your retro heating equipment library.