The Ordway new era., 1911-11-24
TALK ON CAPILLARITY
Moisture Steadily Transferred
From One Particle to Another.
When Surface Of Soil 10 Left Undis-
turbed Tubes Come Close Togeth-
er, Allowing Water to Pass
From One to Another,

Now capillarity is big word, and
It means something pertaining to a
hair. Now hair has very little to do
with the soil and yet "capillarity OF
the soil" is n common term. Very
fine tubes are called capillary. or hair
like tubes. and the word capillary
Is often applied wrongly because we
have no better word to express the
meaning. For instance. take two
sheets of glass and place them in
pan of water. and the water will
flow up between them far above the
level in the pan. and II the glass is
not too long. 1t will run over the top.
writes John Isaac in the Town and
Country Journal. This Is called capIl-
larry attraction. Place piece of wool
en- rag In pan of water and leave
one end Of 1t over the side and the
water will run up the cloth and over
the rim OF the pan. This. too. is called
capillary attraction. yet In neither
case are their any hairs or hair like
tubes. Now. In the soil We often
speak Of the loss of moisture by capil-
larity or capillary attraction, and Of
capillary tubes through which the wa
ter escapes. but there are no such
tubes and no continuous passage be
tween the lower moisture in the soil
and the surface. But there Is a con
stant flow of water through the
soil. and this moisture is being
steadily transformed from one par
ticle to another. Now when the
surface OF the soil Is left undisturbed
t,Io
gether. and the closer they lie to-
gether the more easily the water
passes from one to the other. So If
the ground is left 1t compacts. that
is. the soil particles come closer to-
gether: this forms n very close con
nection between the surface and the
lower layers, and between these
closely compacted particles there are
minute spaces through which the
water raises with comparative rapid
ity. this comes to the surface and is
evaporated by the sun. so that 1t is
lost to the soil and We say the ground
Is dry. In speaking of this process
1t Is often said that the moisture es-
capes through capillary tubes. al
though as you see. there are no tubes
Mt all. only close connection be-
tween the minute soil particles.
which is Just as bad. for it affords a
continuous passage for the water to
come up to the surface and be lost.
To prevent the escape Of this
moisture too rapidly. some people
apply what is known as n mulch to
the soil. or to such parts as they wish
to protect. This Is some kind OF COW
ering. straw or other. which will
shade the ground and prevent the
evaporation OF the water by the sun.
This. OF course. does not prevent the
tens OF thousands OF little pumps
which are at work on every square
foot Of the soil from bringing the
moisture to the Surface. To cheek
this loss and prevent too much OF the
water from escaping. We resort to
what is called 'cultivation." That Is
We keep the surface always broken
up: keep stirring the top soil. SO
that the connection between the soil
particles Is broken up and pre-
vented from being continuous. This
forms what Is called dust mulch.
or n dust covering. and II this is kept
from compacting. 1t prevents the for
nation OF continuous passages for
the water which Is kept In the soil.
until It flows past the trees and plants
whose roots take 1t up and use 1t for
building up their tissues and making
fruit and grain. 1t does not take long
for the particles to settle close to-
gether again. so that they require fire.
quent stirring up. You will under
stand from this the philosophy of
cultivation. or the frequent stirring of
the soil. and why 1t Is necessary.