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.
A relative rarity on the canals is a set of staircase locks.. The upper gate of one lock is the lower gate of another. A lock is filled using water from the lock immediately above it; or, from the other point of view, a lock is drained into the lock immediately below it.hen the tank is finally drained to the same level as the lower body of water, we can open the door on that side (another gate), and steer our boat out. For going up, we steer our boat into the drained lock, close the gate, allow water from the upper body of water to flow in.