Original heating trade vintage catalog for WESTERN ROTARY VENTILATOR COMPANY, INC. was located at 936 Collingwood Avenue, Detroit, MI. and also at 1722 East 14th Street, Los Angeles, CA. Manufacturers of Forbes Syphonaire Roof Ventilators and Ball Bearing Ventilators. Multivane turbine ventilators that are efficient at very low wind velocity, symmetrical in design and silent in operation. Unbound from a large 1931 architectural catalog, this unique old one page technical brochure would display beautifully matted and framed. Nice graphics. A marvelous addition to your retro ventilation equipment library. Slight damp stain on outer edge.