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QUEENSLAND AGRICULTURAL JOURNAL. [1 Sxpr., 1897. - 
In order to clean 
out and prepare the 
bottom of the drain 
for receiving the tiles, 
w special tool called 
a bottom - smoother 
(Fig 10) is used, and 
a special tool is used 
for laying the tiles 
(Fig. 11). In order 
to regulate the depth 
and width of the 
drains, special drain 
gauges are used (Figs. 
12 and 13). Illustra- 
tions of all of these 
tools are given here- 
with, and will not need 
special explanation. 
Fia. 10. 
The following illustrations show a round drain 
tile (Fig. 14), which is the shape always used now, 
and the section of a shoulder tile-drain (Fig. 15) 
showing the tile in position and the last spit that 
as been taken out by the bottoming tool. The 
drain tiles are laid end to end, no especial trouble 
being taken to keep the joints close, though the 
tiles should always be well and evenly laid. When 
the tiles are laid, the drains may be either filled 
in at once, or, if wished, a little blinding of rough 
grass or small brushwood may be placed on the top 
of the tiles before the earth is filled in. 
Fia. 14. Fira, 15, 
The depth at which the drains should be dug and the distance that there 
should be between the drains depend entirely on the nature of the soil, as in 
heavy soils the drains should not exceed 8 feet in depth, or from 18 to 20 feet 
apart, for if placed at a greater depth, or at a greater distance apart, either the 
water would not get down to the drains, or else the latter would not draw the 
whole of the water from the land, all land outside of 9 or 10 feet from the 
drain on each side being outside the influence of the drain. In freer soils the 
depth may be increased, and as the depth is increased so may the distance 
between the drains be increased, but the size of the tiles should be increased 
as well. Draining 4 feet deep and 80 feet apart is about the limit of efficient 
drainage in any soil, as, if the drains are placed at greater distances apart, 
there is more or less land beyond the influence of the drain, which is 
consequently undrained. There is another common mistake in tile drainage, 
and that is, the use of too small drain tiles. Two inches inside diameter is the 
