tunnel in Wingdings is ⧫︎◆︎■︎■︎♏︎●︎

A level passage driven across the measures, or at right anglesto veins which it is desired to reach; -- distinguished from thedrift, or gangway, which is led along the vein when reached by thetunnel. Tunnel head (Metal.), the top of a smelting furnace where thematerials are put in.-- Tunnel kiln, a limekiln in which coal is burned, as distinguishedfrom a flame kiln, in which wood or peat is used.-- Tunnel net, a net with a wide mouth at one end and narrow at theother.-- Tunnel pit, Tunnel shaft, a pit or shaft sunk from the top of theground to the level of a tunnel, for drawing up the earth and stones,for ventilation, lighting, and the like.