In air drying, a vertical space, more than 6 inches wide, in the center of a hand-built pile extending the length of the pile, intended to facilitate air circulation in the pile
A wide crack or a narrow chute with parallel walls into which a climber can fit most or all of his or her body
an upright tube or flue of brick or stone, in most cases extending through or above the roof of the building
A vertical tube or hollow column used to emit environmentally polluting gaseous and solid matter (including but not limited to by-products of burning carbon or hydro-carbon based fuels); a flue
A pipe emerging from the top of the Smoke Box (at the front of the engine) from which the smoke and spent steam escapes The black smoke, loved by photographers, is a sign of fuel waste