in mining, a term used in Cornwall to express openings of the earth either into mines or in search of them. The fruitless openings are called essay-hatches; the real mouths of the veins, tin-hatches; and the places where they wind up the buckets of ore, wind-hatches.

HATCHES also denote flood-gates set in a river, to stop the current of the water, and in particular certain dams or mounds made of rubbish, clay, or earth, to prevent the water issuing from the stream-works and tin-washes in Cornwall from running into the fresh rivers.