Scientific American, Vol. 46, No. 21 (May 1882)
An issue of the weekly New York magazine Scientific American from May 1882, reporting new patents, machinery, and industrial processes for American engineers, inventors, and manufacturers. The engravings are small cutaway and sectional views of machines — threading dies, milling drums, furnaces, pumps — built from dense parallel hatching and keyed letters, useful as mechanical diagram stock, hatched shading samples, and cross-section conventions.
