‹‹‹ Vitr. 8.6.7 | Table of Contents | Vitr. 8.6.9 ›››
8But if the water must be conveyed more economically, the following means may be adopted. Thick earthen tubes are to be provided, not less than two inches in thickness, and tongued at one end, so that they may fit into one another. The joints are then to be coated with a mixture of quick lime and oil, and in the elbows made by the level part of the venter, instead of the pipe, must be placed a block of red stone, which is to be perforated, so that the last length of inclined pipe, as well as the first length of the level part may be received into it. Then, on the opposite side, where the acclivity begins, the block of red stone receives the last length of the venter, and the first length of the rising pipe.
8But if we wish to spend less money, we must proceed as follows. Clay pipes with a skin at least two digits thick should be made, but these pipes should be tongued at one end so that they can fit into and join one another. Their joints must be coated with quicklime mixed with oil, and at the angles of the level of the venter a piece of red tufa stone, with a hole bored through it, must be placed right at the elbow, so that the last length of pipe used in the descent is jointed into the stone, and also the first length of the level of the venter; similarly at the hill on the opposite side the last length of the level of the venter should stick into the hole in the red tufa, and the first of the rise should be similarly jointed into it.