It was considered dÃ©classÃ© to refer to one's own townhouses, estates or villas (or those of friends) as mansions and modern etiquette books still advise that the terms house, big house or great house be used instead.
Waste weir. A waste weir on a navigable canal is a slatted gate on each canal level or pound, to remove excess water and to drain the canal for repairs or for the winter shutdown.
Making It Work. The Lock. A lock enables a boat to pass from a section of canal at one water level to another section at a different water level. Locks also separate two sections of canal so that water from the upper level does not flood the lower level. A boat going from a lower level to a higher level enters the lock through the lower gates, which are then closed by a lock tender.