National boilers, radiators, and specialties: catalog no. 26
A 1920 trade catalogue, no. 26, issued by the National Radiator Company of Johnstown, Pennsylvania for heating contractors, plumbers, and architects specifying steam and hot-water equipment. Halftone photographs show cast-iron radiators, sectional boilers, valves, and air vents isolated on pale grounds, with cutaway diagrams tracing flow by arrows—useful for hardware silhouettes, ribbed metal texture, and technical section drawing.
