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.
In some locations the terms dam and weir are synonymous, but normally there is a clear distinction made between the structures. A dam is usually specifically designed to impound water behind a wall, whilst a weir is designed to alter the river flow characteristics.