Water has been supplied and waste carried away through pipes since ancient times (Staniforth 1994). Supply and drainage systems came into more general use early in the nineteenth century, but the precautions to be found in modern design were not taken. The interceptor and the gully had not been introduced into drainage, and waste and soil were usually discharged into one vertical pipe inside the building leading directly to a sewer or cesspool, often without traps at the appliances. This was the original 'one-pipe system' and because the principles of design with traps and vent pipes were not understood and, in addition, the quality of materials used and of construction were often poor, foul smells in buildings were common. An idea of conditions prevalent even towards the end of the 19th century is given in figure 4.1 reproduced from Teale (1881). Eventually it was required in the UK that washbasins and baths should be discharged outside the building into a vertical pipe leading to a gully trap which also served the sinks, and WCs were served by a separate stack also outside the building — the 'two-pipe system'. Besides the traps at the appliances and the gully trap, the interceptor was introduced to provide a third seal between building and sewer.