1 May, 1902.] QUEENSLAND AGRICULTURAL JOURNAL. 315 
off a quantity of water, and it must be, as I said, a foot deeper than the deepest 
of the minor drains, or rather the lowest of them. It should, if an open drain, 
slope well at the sides and have a width at the bottom of 18 inches. This 
means a considerable width at the top—about 10 or 12 feet—and that means 
the shifting of a lot of soil. But this soil can be thrown up on both sides, and 
planted afterwards with a protecting hedge to prevent cattle getting into the 
drain. As for the other drains, you have already studied a table of distances 
for them. Taking an average of the distance apart required for heavy clay 
soils and sandy loamy soils respectively, they would be 40 feet apart—s0 feet is 
better; still the fewer drains you can do with the better both for your pocket 
and for the land. 
Now, look again at the farm picture. You will see that there is a hollow 
at B, which holds water—a very useful bit of swamp when you first started the 
farm, and lived in a bark humpy, but an eyesore, and one which is of no 
further use since you built a house with galvanised iron roof, and set up a 
number of water tanks. 
You must get this piece drained. Again, at C, there is a rather steep wooded 
slope. The roots of the trees prevent the soil on it from being washed away in 
heavy rain. Still quantities of water rush down the slope at such times and 
damage the crops in the fields below it, so that will have to be remedied. 
How are we going to set about it? The answer to the first question, how to 
drain the swamp A, will depend upon whether the swamp is fed by springs or 
merely by rain water, because each of these cases requires a different method. 
Suppose it is to be fed by rain water, we must not only carry off the stagnant 
water of the swamp, but we must prevent the water from the higher ground 
continuing to supply it. Now you must understand that water coming down 
a hill, does come down the hill, it does not spread out sideways. Some people 
would cut drains 80 feet apart across the line of descent. By doing this all the 
water would require to travel through 30 feet of soil in order to reach a drain. 
_ But if they are dug up and down the slope, it is clear that instead of travelling 
80 feet, the water will only have 15 feet to go before it gets toa drain. If 
there is much higher land above the swamp, then it will be well to cut a 
“heading ’—a drain cutting across the hill and leading into one of the other 
drains, whichever is most suitable to carry off the water. This drain is called 
by road-makers who wish to prevent water rushing down a hillside into a road, 
a “ catch-drain.” 
Now for Question 2—How to drain the hillside (C). People have 
different ideas about the best method to adopt. Some prefer to cut the drains 
obliquely to the line of descent of the water, but others say—and really have 
proved—that the best plan is to do as we did in the case of the swamp—z.e., 
cut the drains straight up the slope—that is, the minor drains—and lead them 
into a main drain at the lowest point. 
Remember what I told you about the length of a minor drain. It should 
not exceed 200 yards. What then is to be done if you have to drain a paddock 
of 400 or 800 yardsin length? In such a case you must put in a“ subleader ” 
or subdrain across the lateral drains, in an oblique (slanting) direction, into 
which they will all lead. 
Great care must be exercised in laying the tiles. Cases have occurred 
where quicksands have been met with which afford no solid bed for the tiles, 
and these have to be specially dealt with by laying a foundation on which to 
rest them. Tile drains, if the tiles are only 14 inches in diameter, often become 
choked, especially if the fall is slight. To obviate this, and cause a quicker 
tush of water, the “pitch” of the pipes is broken; but where the fall is 
sufficient there is no necessity to do this. 
In draining soft, spongy land, it is not advisable to lay the pipes and fill 
in at once, as all such soils shrink and subside when drained, and it may happen 
that the drains will require deepening. In some cases the subsidence has been 
from 6 inches in the shallow drains to 14 inches in the deeper in the short 
space of a month. This actually happened at Dunwich, when Mr. A. Waitt, 
