FOSSES D'AISANCES, a term used to designate the cesspools of Paris. These cesspools are constructed of materials sufficiently impermeable to filtration, so that the matter contained in them shall not penetrate through the walls, to the injury of the adjoining property. So strictly is this condition observed, that any infiltration to a neighbour's premises, according to the French law, gives a title to damages, and the architect and builder are held responsible thr ten years, not only to the proprietor, but also to the neighbours. should any nuisance arise from imperfect execution of the work.
The Fosses d'Aisances are usually made about 10 feet long by about 5 feet 7 inches wide, and 5 feet in height to the springing or the semi-circular head. The material employed in their construction, of late years been nteuth.e or mill stone, bedded in mortar made of Hine and cement ; the inside being well pointed, and rendered throughout with the same. These cesspools are cleansed out when necessary, under th• inspection and by the authority of the board of health of the city ; the carts employed, as well as all the mot,Titt or the nightmen, being under the same surveillance. The
work is done between ten o'clock at night and six o'clock in the morning. The contents of the cesspools are genuralk sufficiently fluid to allow of their extraction by pumps : bat when this is not the case, they arc conveyed from below in small iron vessels ; and great care is taken to prevent. as much as possible. the escape of the noxious effluvia duri the operations. \\ien the soil is pumped into carts, a small furnace is placed over the bunghole of the cart, to burn the gas as it rises ; and directly the cart is tilled, the is plastered over. The lids of the vessels used to venni% e the more solid matter, are also plastered over in a ,inuinn manner, before they are brought out of the cesspools. For a fuller description of the Fosses d'Ais:atccs, see SEWER, SEWERAGE.