Metal work and etching
A 1911 Chicago manual by John Duncan Adams, published by Popular Mechanics Company, teaching metalwork and etching to hobbyists and home craftsmen. The pictures show practical shop illustrations: etched metal panels with geometric and floral patterns, a formed sheet metal tray with raised sides, and dimensioned technical drawings of bent metal parts. A designer might take from them the crisp line-based look of early mechanical drawing and the simple geometric patterns of hand-etched metal.
