subsoil is _firm_, and
where the drain can be bottomed to _fit the tile_. Where large
pipes are not to be had conveniently for sewering main or
sub-drains, I find a proportional number of pipes of lesser
diameter to answer perfectly. It is very desirable to provide
_branch pipes_ for connecting the minor with the main drains. The
branch should be socketed to receive the end of the last tile in
the minor drain, and the point of attachment to the main pipe may
be on the top or on the side of the latter. If the branch be made
to lead the water into the side of the main pipe, then it should
join the latter at an acute angle, that both streams may meet with
the least possible opposition of forces.

_Fall necessary in Tile Drainage._ I consider one foot in one
hundred yards the _least_ fall to work upon with safety.

_Securing Outlets._ All the outlets from main-drains should be well
secured against the intrusion of vermin, by a wrought-iron grating,
built in mason-work. The water may flow into a stone trough
provided with an overflow-pipe, by which the quantity discharged
may be ascertained at any time, so as to compare the drainage
before and after rain, &c.

_Traps, or Silt Ponds._ Where extensive drainage is carried on in
low-lying districts, and the principal outlet at a considerable
distance, it may be found necessary to have traps at several points
where the silt from the tiles will be kept. These traps may be of
cast-iron, or mason-work, cemented; and provision should be made,
by which they can be cleaned out and examined regularly--the
drainage at these periods also undergoing inspection at the
different traps.

_Plow-Draining._ We have no draining-plows in use in Ireland, that
I know of; the common plow is sometimes used for marking off the
drains, cutting the sides, and throwing out the earth to a
considerable depth, thereby lessening the manual labor
considerably. Efforts have been made in England to produce an
efficient implement of this description; but it would appear there
is ample room for an inventive Jonathan to walk in for a profitable
patent in this department, and thus add another to the many
valuable ones brought out in your great country.

_Case of Obstruction in Tiles._ Some years since, one of the
principal