keep loose dirt from getting into
them.

*Collecting the Water (C)f Springs.*--The lateral which connects with the
main drain, _A_, (Fig. 21,) at the point _m_, and which is to take the
water of the spring at the head of the brook, should not be opened until
the main has been completed and filled into the silt-basin,--the brook
having, meantime, been carried over the other ditches in wooden troughs.
This lateral may now be made in the following way: Dig down to the tile of
the main, and carry the lateral ditch back, a distance of ten feet. In the
bottom of this, place a wooden trough, at least six feet long, laid at
such depth that its channel shall be on the exact grade required for
laying the tiles, and lay long straw, (held down by weights,) lengthwise
within it. Make an opening in the tile of the main and connect the trough
with it. The straw will prevent any coarse particles of earth from being
carried into the tile, and the flow of the water will be sufficient to
carry on to the silt-basin any finer matters. Now open the ditch to and
beyond the spring, digging at least a foot below the grade in its
immediate vicinity, and filling to the exact grade with small stones,
broken bricks, or other suitable material. Lay the tiles from the upper
end of the ditch across the stone work, and down to the wooden trough. Now
spread a sufficient layer of wood shavings over the stone work to keep the
earth from entering it, cover the tiles and fill in the ditch, as before
directed, and then remove the straw from the wooden trough and lay tiles
in its place. In this way, the water of even a strong spring may be
carried into a finished drain without danger. In laying the tile which
crosses the stone work, it is well to use full 2-1/2-inch tiles in the
place of collars, leaving the joints of these, and of the 1-1/4-inch
tiles, (which should join near the middle of the collar tile,) about a
quarter of an inch open, to give free entrance to the water.

The stone and tile drain, _H, I_, is simply dug out to the surface of the
rock, if this is not more than two feet below the grade of the upper ends
of the laterals with which it connects, and then filled up with loose
stones to the line of grade. If the stones are small, so as to form a good
bottom for the tiles, they may be laid directly upon it; if not, a bottom
for them may be made of narrow strips of cheap boards. Before filling, the
tiles and stone work should be covered with shav