Flue pipe

Flue pipe (Fr.: tuyau à bouche; Ger.: Labialpfeife, Lippenpfeife), organ pipe having a flue or windway between the edge of the languid and lower lip if it is a metal pipe; or, if it is of wood, a flue between the top edge of the cap and the *block. Flue pipes may be open, stopped, or half-stopped, and may be made of metal or wood. Metal pipes are usually round, wooden ones square. Other materials have been used exceptionally (101). Hunt, N. A. Bonavia. Modern Organ Stops. London, 1923.