But when it was required to conduct water at less expense, tubes of earthen-ware were made, having a thickness of not less than two inches, and these tubes were so formed that one end being tongued, the

one entered the other then the joints were cemented with quick lime, tempered with oil. In the descents, level with the venter, a stone of the red kind is to be placed at the angles, so perforated that the last tube of the decursions and first on the plane of

the venter may be joined to the stone so likewise at the opposite acclivity, the last in ;

the plane of the venter, and the first of the expressure are to be in the same manner united to the red stone. Thus the tubes on the even plane, as well as those in the decursions, will not be split, for such violent vapors are apt to rise in conduits of water as would even burst through stone, unless the water was at first gently and sparingly admitted from the spring, and the bendings secured with ligatures or weights of ballast in all other respects they are built in the same manner as leaden pipes. ;

When first the water is admitted, ashes are sent before it, that if any of the joints should not be sufficiently cemented, they may be stopped by the ashes.

Aqueducts of tubes have this advantage if any damage happen, any person may rectify it, and water from earthen tubes is far more wholesome than that from pipes, as the use of lead is found to be pernicious. We should not, therefore, conduct water in pipes of lead, if we would have it wholesome. The taste also of that from the tubes is better, as is proved by our daily meals ; for all persons, although they have tables furnished with silver vases, use fictile ware on account of the purity of the water.