y miles of drains have been made on the farm, the
least distance apart being twenty-one feet, and the greatest
distance thirty feet; the depth in every case, three and a half to
four feet for minor drains. This drainage has given the greatest
satisfaction; for although the greatest part of the work was
performed by the Agricultural pupils, in training here, we have not
had occasion to re-make a single drain, except in one instance,
where the tiles got choked, and which I shall explain hereafter.

_Tiles: Size, Shape, Draining, Capacity, &c._ We use circular pipe
tiles, of inch and a half bore, for all parallel drains whose
length does not exceed one hundred yards, and two-inch pipes for
any additional length up to one hundred and fifty yards, the
greatest length, in my opinion, a parallel drain should reach
before discharging into a main or sub-main drain. We do not find it
necessary to use collars on this farm, as we have _firm_ ground to
place the tiles on, and we can cut the drain to fit the tiles
exactly. As regards the size of tiles for main and sub-main drains,
_that_ can only be regulated by the person in charge of the
drainage at any particular place, after seeing the land opened up
and the minor drains discharging. As a general rule, a circular
pipe of three inches internal diameter will discharge the
_ordinary_ drainage of five or six statute acres, and give
sufficient space for the circulation of air. It should be observed,
however, that this applies to a district where the annual rain-fall
is from twenty-six to thirty inches, that of all Ireland being
about thirty-five inches; besides, we have not the immense falls of
rain in a _few hours_ that occur in other countries. All these
points should be carefully considered in estimating the water-way
for drainage. I have said that collars are not used with the tiles
on this farm, as the bottom of the drains is quite firm and even;
but, where the bed for the tile is soft, and the subsoil is of a
_shifting_ nature, then collars should be used in every case.
Collars cost about half the price of tiles, which they are made to
connect, so that the use of them adds one-third to the expense of
the sewering material; and, as I have already pointed out, I think
it quite unnecessary to use them where the