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.
Canal. in hydraulic engineering, a regularly shaped man-made channel (waterway) built in the earth, with nonpressured movement of the water. Canals are built in open excavations or in embankments (when crossing gorges or ravines) and sometimes half in excavations and half in embankments (a canal on a slope).