Scientific American, Vol. 28, No. 15 (April 1873)
A single April 1873 issue of Scientific American, the weekly illustrated journal of invention and patents published by Munn & Co. in New York for mechanics, manufacturers and would-be patentees. The 24 wood engravings show machine tools, drill presses, lathes, valves and boiler fittings in three-quarter and side elevation, built up from dense hatching and stipple on white ground, with lettered part keys and figure numbers useful as isolated mechanical silhouettes or line-shading reference.
