Quicklime Burned in a Rude Stone Kiln, Ure 1839

Limestone burned hot gives off carbonic acid and leaves quicklime. Andrew Ure (1839) describes the oldest kiln: a ring of rough stone walls filled with layers of fuel and broken limestone over brushwood, the top heaped into a cone and covered with sods so it burns slowly and evenly. Quicklime heats hard with water and burns the skin: keep it dry and wear gloves and glasses. The picture: quicklime powder on a watch glass.