The farmer and mechanic. [volume] (Raleigh, N.C.) 18??-19??, 1910-11-08
DRAINAGE WORK NOW DUE
SOME VERY IMPORTANT SUGGESTIONS FOR LAYING OUT
PLANS WHICH BRING THE FARMER BEST RESULTS
CIV. R. Gilbert.)

The average life of the drains In
many soils IS probably not more than
twenty-five years, and even il the
drains are not as old as that they may
have become blocked by roots of trees
or singage Of indiV dual pipes.
The point then to decide will be
whether to take part Of the system
and relay. or an n rely
new one. In the majority OF cases 1t
will be found that it IS most satisfac-
tory to lay dow an entirely new sys-
tenn and this is the course generally
adopted.
In laying out a new scheme Of tile
ira mage the following are the main
points that WI require Investigation
before the working plan can be pre-
pared of the work commenced.
No rule Of thumb can be given, but
It may be said that On the heavier
clays a 4 stance apart Of 81 yards
and an average depth two feet, nine
inches would be ample while on the
lighter sands and wet gTavels 20 yards
apart and an average Of three feet,
three inches for depth would not be
TOO much. AS a general rule on med
ium soils minor drains are set eleven
yards apart and three feet deep.
Drains need not to be SO near to-
gether on arabic as in grass land.
ORA ms should be at an average OF SIX
inches deeper than the side dra MS
Main drains should have a fall Of
not less thar one in $50 or about 20
feet per mile. The actual position OF
minors with reference to the slope
has been the subject of much Discus
son, but where the fall is fairly good
they may be taken across the slope
and this is generally the most practi-
cattle way.
The number OF square yards In an
acre (44S0) divided by the distance
anarf nf tho minors VIII give the to-
tai length of side drains psr acre.
This. if the side drains are II yards
apart, their total length on an acre of
Of ground will be 40 yards.
Choosing the pos tons for the out
falls is often by no means an easy
task. but it may be taken as a prin-
ciple that the fewer outfalls there are
the better, as each requires to be
cleaned out periodically, and If there
is a nultipl cation Of them one or
the other is certain to be overworked
some time. The outfali should be
placed as far above the water level
Of the stream or ditch into which it
empties as circumstances VII allow,
but If there IS any chance OF flood
water bacFing up the dain, this must
be provided against by fastening an
hinged flap over the end Of the out
fall pipe.
when the whole system has been
SSo1p o1t CIiIs 1lAS AC1Ni III
tiles should be taken on to the ground
and I'D in convenient size heaps near
20 the place at which they Will be
needed.
IN the selection Of tiles great care
should be taken for n this as in many
other things Of strength cf 2 chain
Is its weakest link and through the
flying" of a main drain the great I
part OF an entire drainage system ma
be rendered COmparat Vely useless.
Drainage tiles should be evenly and
well burnt, giving a clear, ringing note
when clinked together. They should
also be of even texture throughout
and. although an odd pebble embedd-
6ed II their substance here and there
is not of muCh consequence. the pres
enca Of nOdlules of limestone is high
~ dangerous, as these, if large. will
often cause the title Fly" when damp
ed. after burning, and this may easily
occur when the title s. laid and Out
Of sight. The tiles should be regular
in shape, Of even bow and their nc
should be fiat and square SO hat wher
lad they may show no open Joints.
The size Of the pipes depends or
che amount of water they are expect
ed to drain, but the usual S yes uset
in under drainage are two inches il
diameter. which,, however, f Of IN.
considerable length, should be prOvid
ed VT: sfs inch ame tiles in the
lower lenEths.