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.
Quick Answer. A canal lock connects two bodies of water at different elevations by creating a water elevator of sorts. The water inside the lock can be raised and lowered independently, allowing ships to make the transition between elevations without the danger of traveling down rapids or the difficulty of steaming uphill. Keep Learning.