Original old building material construction vintage catalog  VENT-O-LITE COMPANY of Chicago, IL.  Industrial Skylights and Ceiling Light Sash, Roofing. A skylight for every type of roof.  Disbound from a large 1938 construction book, these unique 2 page technical data specifications sheets contain a small amount of residual glue, and pages are loose. It would make a sensational addition to your architectural engineering library.