mining, a term used in Cornwall, to express any of the openings of the earth either into mines or in search of them. The fruitless openings are called effay-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, &c., to stop the current of the water, particularly certain dams or mounds made of rubbish, clay, or earth, to prevent the water that issues from the stream works and tin-washes in Cornwall from running into the fresh rivers.