On Draining Running Sands. 
117 
the lower one being reversed, and the upper placed upon its edges 
half the length of the tile backward, that the ends of the upper 
and lower tiles may not come together, which will break the 
joinings throughout the whole drain. If the latter plan be 
adopted, the minor drains are laid level with the edges of the 
reversed tile ; if the former, about two inches descent is given at 
the entrance of the main drain. 
All rapid falls are particularly avoided, or the drain will wash 
away in spite of all precaution, especially where a strong run of 
water occurs. Where a fall of 1 in 100 cannot be avoided, it is 
necessary to beat clay into the bottom of the drain under the 
soles. In setting out the minor drains, the distance of each is 
regulated, as already pointed out, according to the openness of 
the land and the depth of the water. All long runs are also 
avoided, the length being no more than from 3 to 5 chains. I 
need scarcely say that the whole of the land is thrown level, so 
that there is neither ridge nor furrow to regard. 
We shall now consider the most important and critical part of 
the work, which is the taking out of the bottom spit, and the lay- 
ing of the tiles and bottoms ; but most of all, the securing of the 
tiles from admitting the quick running sand. The two men who 
cut the drain to its proper depth, work as near to each other as 
possible, and the tile-layer quite up to the latter, or the drain 
would be immediately closed up by the sand running in from the 
sides, which would also let down the mass from the surface. In 
other words, when the first man has got a few feet from the end 
of the drain, the second commences taking out the bottom spit, 
and as soon as he has made way for the laying of three or four tiles, 
it is immediately done by the tile-layer ; first laying the bottoms 
quite close to each other, and upon them the tiles, leaving as little 
cre\-ice as possible, and immediately covering them with about 
4 inches of the most tenacious soil that can be procured. Clay 
would be used, but on account of its being in large hard lumps, 
It cannot be made to bed sufficiently close to keep out the sand. 
Here I must notice, that it is essentially necessary that the drains 
be cut 3 or 4 inches wider at the bottom than the width of the 
tile, so as to admit this strong soil down the sides to the very 
bottom. Much mischief is done by the sand getting in at the 
bottom part of the joinings of the tiles. Other materials have 
been used for keeping out the sand, but with bad effect. I prefer 
clay to anything else when it can be got sufficiently loose and 
malleable, so as to bed quite close and firm, and leave no crevice. 
Straw, and all perishable materials, are particularly avoided. 
When the season is wet (although from many considerations a 
dry one should be chosen if possible), and when the drain is deep, 
great difficulty is found in keeping the sides from falling in before 
