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.
1 Aqueduct (bridge) , a bridge that is constructed to convey water over an obstacle, such as a ravine or valley.2  Navigable aqueduct (or water bridge), a water-filled bridge enabling boats, barges or ships on a waterway to cross over an obstacle, such as a ravine or valley. Aqueduct (water supply) , an artificial (man-made) channel that is constructed to convey water from one location to another. 2  This can be made of canals, pipelines, inverted siphons, reservoirs and tunnels. 3  Roman aqueduct, water supply systems constructed during the Roman Empire.