The first simple system of a pipe running from the sink to a point outside the building was sufficient. As larger buildings came into use and communities were more thickly populated, the plumbing problem demanded thought and intense study. The waste pipes from fixtures had to be so arranged that it would be impossible for foul odors and germ-laden air to enter the building through a plumbing fixture. The importance of this is evidenced by the plumbing laws now in use throughout the country. One of the first plumbing fixtures put into common use was a hollowed-out stone which served as a sink. It was with considerable interest that the writer saw a sink of this kind in actual use in the summer of 1915, at a house in a New England village. This sink had been in service for about 100 years.