no city, Spain: Strebelwerk Mannheim, no date, ca. 1930. Pamphlet. Unpaginated text and three fullpage sepia plates (plus litho'd cover image in colors), 6x9.5 inch oblong pamphlet in staplebound color wraps. Front cover mildly edgeworn and handled with a touch of dust, back cover bears a sprinkle of adhesion scars that marginally affects the graphic there; staples are rusted with some migration at the centerfold, a good (good-only) copy. Cover litho is a snowbound house, rear image a heavy-duty indoor heater. Plates within show people in various rooms, different sorts of heater unobtrusively at work in each.