[ no place ]: American Radiator Company 1927.  pages. Stapled self-wrappers. 4 3/8 x 7 1/2 inches. Overall wear and soiling - a used copy. Good. Wraps. 
A brochure no doubt used by installers and/or estimators that shows the various available sizes of CORTO radiators and their heating surfaces (square feet), etc. The brochure includes information on 3, 4, 5, and 6 tube CORTO radiators, and also window radiators. These were forced hot water heaters, and the form is very familiar to anyone who has ever lived in an older apartment building.