Pressure Reactor: the Cast-Iron Autoclave with Bolted Cover (Thorpe, 1912)

The chemical works' autoclave, built on Papin's digester: a closed cast-iron vessel with a flanged cover bolted down on a lead washer, a pressure gauge, a safety valve and a thermometer tube. It heats liquids above their boiling points, often at 20 to 30 atmospheres, in a bath of hot oil or molten lead. Variable: the material (cast iron, steel, copper, sheet iron) and lining (enamel, tin, lead, copper or zinc). Source: Thorpe, Dictionary of Applied Chemistry, vol. I (1912), pp. 343-344. Unknown: sizes, wall thickness. Picture: Fig. 3 of the book.