The house drain is the means for conveying the sewage from the dwelling. Its proper material is a question of great importance. Outside of the dwelling it should be of vitrified pipe, circular in shape, which is superior to cement pipe.

Iron pipe for outside drains is preferable in made ground, or in quicksand, also where trees are near the line of the drain, and where the drain must necessarily pass near a well furnishing water for the household.

Neither brick channels nor wooden conduits should be used as house drains. Only strong, hard, well-burnt, vitrified pipe, free from cracks or other defects should be used. Four inch pipes and those of smaller size are especially liable to warping, and should be carefully inspected and selected. The interior of these pipes should be well-glazed and smooth throughout; the pipes should be impervious, true in section, perfectly straight, and of a uniform thickness. Four inch pipes should have a thickness of 1/2 in. to 5/8 in.; six inch pipes 11/16 in. to 3/4 in.; nine inch pipes should be not less than 3/4 inches thick; 12 inch pipes should be 1 inch thick; fifteen inch pipe 11/4 in., and eighteen inch pipe should have a thickness of 11/2 inches.

The joints of the pipes should receive particular attention. The danger arising from imperfect or leaky joints is twofold, namely, first, the sewage, by soaking into the ground, pollutes the soil and endangers the purity of the water supply in places where houses are dependent on wells and cisterns for water. The ground around and under the house is more and more subject to contamination, and in winter time, when there is a strong inward draft into houses from fireplaces and stoves, the tainted "ground air" is thus sucked into our very living and sleeping rooms, often producing severe illness. The second danger resulting from leaky joints is equally patent. The solid matters, carried in suspension in the pipes, are deprived of a part of their liquid carrier, and thus tend to accumulate and form deposits in the house drain, which deposits soon undergo decomposition, and till the drains and pipes with noxious gases.

Vitrified pipes are made either with a socket or hub attached to one end of the pipe, or with both ends plain. When socket pipe is used, special grooves should be cut in the bottom of the trench for the hub, in order to give the pipe a solid bearing on its entire length. The pipes are laid with the socket pointing upgrade, the plain or spigot end of one pipe being inserted into the socket of the next. Spigot and socket ends should be concentric. Into the annular space between both a gasket of picked oakum is introduced and firmly rammed by a hand iron. The remainder of the space is then filled with pure cement, or cement mixed with an equal volume of sand. No lime should be used with the mortar, which should be prepared only in small quantities at a time, to prevent its setting before use. Particular attention should be given to the bottom part of the joint, where the mortar should be pressed into it with the fingers. If water accumulates in the trench, this should be carefully removed from the grooves before making the joints, and sufficient earth should be thrown into the groove to support the mortar at the bottom of the joint, until it has time to harden. The gasket of oakum prevents any cement from projecting into the inside of the drain, and renders the use of a rattan and rag, with which to wipe the inside of joints, unnecessary. Where the sockets are insufficient in length to permit the use of a gasket, it becomes important to clean the joints of cement projecting at the inside, but in this case a better device than a rattan with rag tied to it is a strong handle to which is attached a a semi-circular disc of wood, of a somewhat smaller radius than the radius of the pipe.

The cylindrical pipe without sockets is preferred by some. The joints, in this case, are made by butting two pipes together, and covering them with rings or collars of unglazed terra cotta, applying cement to the inside of the collar and to the ends of the pipes.

Some object to the use of cement for drain pipe joints, claiming that the stiffness of the cement joint after hardening will tend to break the pipes in case of a slight settling. They also maintain that some cements increase considerably in volume when setting, and tend to burst the sockets. They much prefer a ring of puddled clay, pressed into the joint and wiped around it, claiming that clay will make a tight and more elastic joint. But in ordinary cases the settling of drain pipes may be prevented by providing a solid foundation of either gravel, sand, or concrete, or in very wet ground, boards or piles as supports to the pipe. In made ground I should recommend the use of iron pipes to prevent leaky joints or breakage of pipes. A good Portland . cement will not much increase in volume after setting, and I believe it has been shown that those cements which largely increase their volume, often lose their hardness after some time, and would be, therefore, unfit for any use.. While I fully appreciate the advantage of a somewhat elastic joint, I do not think that puddled clay will make as tight a joint as seems desirable for drains carrying foul sewage.

What is known as "Stanford's Improved Pipe Joint" has been used extensively of late in works of house drainage in England, and its superior merits are such as to recommend it for use with us. I, therefore, introduce a brief description. "In sewer work in bad or wet ground, just where a sound joint is most required, the difficulty of making it is the greatest. What is wanted, therefore, is a joint that will entail the least disturbance of the ground, that will not necessitate the absolute drying of the trench bottom, and that will require the minimum of time, skill, and labor in making it. These conditions will be fulfilled in the most complete manner by making the spigot of one pipe to fit mechanically into the socket of another, as in a bored and turned iron pipe joint. Such a mechanical fit cannot be obtained with stoneware or earthenware pipes, owing to the difficulty of preserving perfect accuracy of form during the process of burning."