Ferrules first appear in the Assyrian iron of the 7th century B.C. The rise of stone work led to great importance of heavy chisels (36) for trimming limestone and Nubian sandstone; such chisels ate usually round rods about 3/4 in.
But even in entirely new distributing systems the network is so extensive, and the number of joints so great, that the aggregate leakage is always considerable; the greatest loss being at the so-called " ferrules " connecting the mains with the house " communication " or " service " pipes, in the lead pipes, and in the household fittings.
But this did not obviate the necessity for house - to-house inspection, and although the number of different points at which leakage occurred was still great, it was always small in relation to the number of houses which were necessarily entered by the inspector; moreover, when the best had been done that possibly could be done to suppress leakage due to domestic fittings, the leakage below ground in the mains, ferrules and service pipes still remained, and was often very great.
The system, however, does not assist in the detection of the leakage which inevitably occurs between the reservoir and the consumer's meter; thus the whole of the mains, joints and ferrules connecting the service pipes with the mains, and the greater parts of the service pipes, are still exposed to leakage without any compensating return to the water authority.