bits of tile, or other suitable covering, around the
connecting joint.(20)

[Illustration: Fig. 33 - LATERAL DRAIN ENTERING AT TOP.]

Fig. 33 - LATERAL DRAIN ENTERING AT TOP.

When the main drain is laid with collars, it should be so arranged that,
by substituting a full tile in the place of the collar,--leaving, within
it, a space between the smaller pipes,--a connection can be made with this
larger tile, as is represented in Figures 33 and 34.

[Illustration: Fig. 34 - SECTIONAL VIEW OF JOINT.]

Fig. 34 - SECTIONAL VIEW OF JOINT.

*Silt-Basins* should be used at all points where a drain, after running
for any considerable distance at a certain rate of fall, changes to a less
rapid fall,--unless, indeed, the diminished fall be still sufficiently
great for the removal of silty matters, (say two feet or more in a
hundred). They may be made in any manner which will secure a stoppage of
the direct current, and afford room below the floor of the tile for the
deposit of the silt which the water has carried in suspension; and they
may be of any suitable material;--even a sound flour barrel will serve a
pretty good purpose for many years. The most complete form of basin is
that represented in Figure 24.

[Illustration: Fig. 35 - SQUARE BRICK SILT-BASIN.]

Fig. 35 - SQUARE BRICK SILT-BASIN.

When the object is only to afford room for the collection of the silt of a
considerable length of drain, and it is not thought worth while to keep
open a communication with the surface, for purposes of inspection, a
square box of brick work, (Fig. 35,) having a depth of one and a half or
two feet below the floor of the drain,--tiles for the drains being built in
the walls, and the top covered with a broad stone,--will answer very well.

[Illustration: Fig. 36 - SILT-BASIN OF VITRIFIED PIPE.]

Fig. 36 - SILT-BASIN OF VITRIFIED PIPE.

A good sort of basin, to reach to the surface of the ground, may be made
of large, vitrified drain pipes,--such as are used for town
sewerage,--having a diameter of from six to twelve inches, according to the
requirements of the work. This basin is shown in Figure 36.

Figure 37 represents a basin made of a 6-inch tile,--similar to that
described on page 130, for turning a short corner. A larger basin of the
same size, cheaper than if built of brick, may be made by using