Illinois Thermo Modulating System of Vapor Heating for Apartments, Hospitals, Hotels, Schools, Residences Vapor System Details. Bulletin Number 22

A. I. A. File Number 30c2. A vintage softcover trade catalog by the Illinois Engineering Company, 24 pages. Saddle stapled binding. Brown paper wraps with the title at the front cover. Printed in black and white on thick, slick paper with many illustrations and tables throughout. Catalog sticker to the upper left corner of the front cover. White spotting to the insides of the covers and some brown spotting scattered throughout the pages (particularly at the first and final pages). Smithsonian Libraries DEC 14 1983 stamp to the lower left corner of the final page. Otherwise, pages are clean and free of writing. The binding is tight and strong, with no loose pages. With descriptive sections on the Illinois heating system entitled The Illinois Vapor System of Heating, True Vapor Heat, and Proof That Illinois Vapor Systems Operate of Vapor Pressures; sections on parts of that system entitled Illinois Heat Retainor, Illinois Thermo Radiator Trap, Illinois Modulating Valve, and Illinois Return Trap; and sections describing typical installations entitled Typical Elevation - Type A System, Typical Boiler Room Assembly, Type B System - Residential, Basement Piping Plan, among others. Each of these descriptive sections includes at least one illustration or diagram. With instructions for Computing Radiation and Boiler Sizes as well.…