Green-Mountain freeman. [volume] (Montpelier, Vt.) 1844-1884, 1871-11-01
agricultural.
How Drains Operate

a correspondent of the Practical FaTaer
contributes the following interesting in
fOrmatiOn resp citing the operation of drains:
After Conversation with various practical
farmers, ] am satisfied that many of them do
not fully understand the correct theory OF
the action of drains. To those who do not
give the matter their careful attention, j.
will seem a very simple matter to understand
how, when II ns. or when from some other
cause water accumulates in the soil, it should
escspe by sinking down into a we'll made
drain but Just feTe is where a mistake II
made, for the water does not cnme into the
drain from the top hut from the bottom Of
tht drain or, in other words, the surplu-
water comes up into the drain not jwn in
70 it. In low lands there point at whic
the soil remains saturated with water, and
the distance Of this pO III from the surface
will OF course vary with the faculty offer
FIR the di.charge of the surrlu, water
" here this point II SO near the ace L.
effect the roots Of the lHruier's GRIPS. ram
are need d, and shOu'd he used, IN order L
keep this line OF saturatinn on a level VIII
81 cir bottoms. In order to simplify The
mater, this line OF saturntiun has he, D styler
the water able In case o. n heavy rim tie
water will sink down until 1t reaches thi-
water table, which, from the accumulation
Of water, will gradually rise until lin tile
hHseu e o. uEdlH-l IL mus Il natural outlet
The amount Of damage done 10 the farmer
will, OF course, depend upon the height OF
this outlet; in some cas- 1t is 50 high as [
overflow tie surface, md Others will no.
reach the surface, hut still is high eaougi
to TO do damage to the growing crops. T.
explain more clearly ny meaning, ruppus
a barrel er-tIght) to be filled with cuuI-
mon soil, nd small openings ade at differ
ent heights along its side; now supPos,
water 10 De DO irrd So slowly upon the sur
face Of 1be sill that il Will be absorbed az
fast az 1t is poured in,-the earth will react
a point at witch 1t will hold no NOR
water, and it W II accumulate at the bottom
OF the barrel. Ii the addition of water II
cOntinu, d, the artificial water table will mol
rise, ard the surplus water will pass of at
the lowest opening II TIE water Is added
faster than one OIening can cry IL off. u
will rise to next above, and in this way will
II the water Is ADDED fast enough overt Dv
the t. p OF the barrel In all cases the sur
plus water v Ii rise TO the lowest OpenIng.
and not fail to escape by the upHer one.
Tois IL exactly what takes place with drain.
As soon as the drain IS Opfned IL lowers tie
water table to It's own level, and If the watel
dies not come in faster than the drain car
carry II off, viii hold it there Ia one cas-,
| was told by practical farmer, who had
drains in successful operation, that this idea
was not correct, for if it was, one drain
would lower the water table on an acre OF
ground, and should prove sufficient to drain
it properly But in the capillary attraction
OF the soil, this objection would hold good
Different soils possess the power of holding
water in different degrees, and hence no ruiz
for spacing drains VIII hold good they may
be, and often are, far apart that the capIl-
airy attraction OF the soil counteTacts the
tendency Of the watar TO seek the level drain
and hence we find whore the drains are too
far apart, that he water table is not level
but rises nearly Do. quite to ne surface, mid
way between tie drains. but over them fall,
to their Levi he line of eaturation Is g
wonderful pryvi-i,n Of nature, whereof,
moisture is iuru sIed Just as it is needed
and, and in prop. quantities, provided it il
at the proper ~ra &c from the surface
this point - to far from the surface, tht
power Of capillary attraction will be over
ctme by the weight OF the water-and if to-
near the sur ace, tie crop will be injured b.
its roots coming n contact with the water
From what nave already written, we ma
see why dIa land IL SD much less liabI
10 'W,sr than that which is undrained l.
for the water having a free passage through
the soil to tile level Of the water table vii
pa off in the dram, instead OF over the sur
face OF the soil.