view, with the exception of the trap itself. This, as may well be supposed, is often a valuable feature. Generally when this style of vent is used, the material employed on both waste and vent is either brass or galvanized wrought iron, although lead may be used if for any reason it is found to be more desirable.

In a great deal of work on which the continuous vent is used, the cost of stock and labor involved is very much less than when the same work is installed according to the methods shown in the preceding chapter. This is particularly true of certain classes of large work. Fig. 62, for instance, shows the continuous vent prin

Horizontal Moin Vent

Horizontal Main Woste

FIG. 62.-Continuous Venting for Line of Fixtures.

ciple applied to a line of fixtures, both front and end views being given. To this type of work the principle is particularly adaptable, and is being constantly employed to a greater extent. The method allows both horizontal main waste and main vent to be run back of partitions, concealed from view. Another material advantage of the continuous vent is the fact that the vent is taken off so far from the trap that the rate of evaporation is far less than under the conditions existing in work as ordinarily constructed. This is a more important feature than is generally acknowledged, for many traps, otherwise properly installed, fail because of the evil due to evaporation. In Fig. 63 is shown a vertical line of fixtures entering a waste stack, the traps being provided with con

tinuous vents, and in Fig. 64 the same style of work in connection with a double line of fixtures on opposite sides of a partition. Double lines of fixtures are very often to be found on large work, such as apartment and office buildings, hotels, schools, factories, etc., and on such work as this there is no question whatever that the saving in labor and material is very great.

In Fig. 65 is shown a water-closet vented from the vent hub of a vented T-Y, a method which is very acceptable. This particular vent is not generally spoken of as a continuous vent, but it actually is in principle, and is therefore considered in this chapter. Such

FIG. 67.—Continuous or Circuit Venting of Water-Closets.

work is very substantial, and particularly adapted to locations in which the plumbing is liable to rough usage, as, for instance, in factory work.

Fig. 66 shows the use of special patented fittings designed for vent work, the principle being very similar to that involved in the work of Fig. 65. In this connection it may be said that a great variety of vent fittings are now made, many of which will be noted in later illustrations, which are of very great value in the construction of continuous venting. Another modified form of continuous vent is to be seen in Fig. 67. This style of work, known as circuit venting, is applicable only to batteries of water-closets,

but as it often happens that in the plumbing of hotels and other public buildings, extensive toilet rooms are located one above the other, the occasion often arises where the principle referred to may be put to good use. The illustration shows a line of waterclosets on one floor only, but similar work on floors above or below would be put in in a like manner. The idea consists in the location at either end of the line of water-closets, of a vertical stack, one for soil and waste, and the other as a main vent. Each vertical line is carried through the roof, thus affording abundant circulation of air for each line of fixtures. Here again a great saving is made in labor and material over the separate vent method, in which a vent is taken from each lead bend. In the case of such work as that of Fig. 67, if fixtures other than water-closets waste into the horizontal soil pipe serving the water-closets, the vents from such fixtures may be run in the ordinary manner and connected into the vent stack.

It may be said that the continuous vent will prove a most valuable feature in the attainment of a perfect plumbing system, and that when its value becomes more thoroughly understood and appreciated, it is bound to be universally adopted. Indeed, it appears strange that it is not already put to more extensive use, as it certainly is a solution of some very serious problems.

CHAPTER IX

HOUSE SEWER AND SEWER CONNECTIONS

HAVING now considered the two fundamental subjects of traps and venting, the entire plumbing system will be considered, beginning at the point where the house sewer connects into the public sewer. Before proceeding with the subject, it will be well to define several terms, which are not always clearly understood.

By house drain is meant that portion of the horizontal drainage system into which all soil, waste, and drainage pipes discharge within the walls of the building which the drainage system serves. The house drain conveys the drainage to a point outside the foundation walls into the house sewer.

By house sewer, lateral or main drain, is meant that portion of the horizontal drainage system which extends from the house drain outside the foundation walls into the public sewer.

By house connection is meant that part of the house sewer which lies between the public sewer and the curb line.

By crock drain or sewer is meant any drain or sewer constructed of vitrified earthenware, hub and spigot pipe.

By tile drain is meant any drain constructed of hard-baked earthenware pipe, which is laid with open joints, and having no hub and spigot ends. Tile drain is a name often wrongly applied to the crock drain.

The house drain usually ends at a point 10 feet outside the foundation walls, and at this point enters the house sewer, which is generally constructed of vitrified earthenware pipe, although occasionally the cast-iron pipe of the house drain is continued to the public sewer.

No earthenware pipe should be allowed inside the foundation walls of any building, on any part of the drainage system. All plumbing ordinances now make this prohibition. The reason for this is that owing to their nature, the cement joints used on this