THE USE AND CARE OF WATER
The ocean is the home of the water.
The water would always remain in the ocean if it could,
but the sun and air are continually at work stealing
little particles away and sending them on long journeys.
The water particles are so small as
they rise from the ocean that we cannot see them.
By and by they crowd together and make the clouds that
float across the sky. As soon as the clouds meet
colder air, the little water particles rush together
and thus become larger and larger until they grow
so heavy that they can no longer float in the air,
but must fall. Some of them fall into the ocean
again, but others drop upon the land.
The raindrops that reach the land
have many sorts of stories to tell before they again
get back to the ocean. Some of them are at once
snatched up again and are started upon another journey.
The thirsty air, whether over the ocean or over the
land, is ever in search of water particles.
If the air is very cold, the clouds
turn to snow instead of rain. The feathery flakes
fall slowly through the air and form a soft white mantle
over the earth. Those that fall on lofty mountains
form great banks which may not entirely melt and turn
to water until late in the summer.
The raindrops that fall where the
slopes are steep, where Nature has grown little vegetation,
or where men have destroyed the earth cover, have
little to detain them and are soon on their way back
to their home. In their hasty journey they do
much damage to the unprotected soil.
If the drops fall upon gentle slopes,
or where there are marshes and lakes, or upon the
forest with its decaying vegetation, or upon deep
beds of gravel and sand, they are a long time getting
back to the ocean.
We can in no way change the amount
of rain that falls upon any part of the earth.
We cannot call up a storm when we wish it, nor can
we send it away when there has been rain enough.
But there are many ways in which we can hasten or
delay the return of the water to the ocean. Nature
shows us some of these. The spongelike carpet
underneath the forest holds the water until it has
had time to soak into the earth from which it later
emerges as springs. Nature forms basins on the
heads of the rivers where a part of the water, instead
of immediately flowing away, collects in the form
of lakes. From these lakes the water runs away
slowly instead of in torrential floods.
Only a few places in our country have
more rain than is really needed. One of these
is the region about the mouth of the Mississippi River
upon the Gulf of Mexico. Another is upon the Northwest
coast. Throughout the central part of the country
the summer rains are sometimes too light to afford
a full harvest. The rainfall upon the plains and
valleys of the Southwest is so small that the only
plants that can live there are those strange and curious
forms that have become used to desert conditions.
The only way in which these lands can be made useful
to the farmer is by means of irrigation. To obtain
water for irrigation we have either to go to the distant
mountains and build reservoirs to collect the rains
which fall there and then dig canals to carry the water
to the desert valleys, or to make use of some river
flowing through them, if they are fortunate enough
to have such a river. Can you think of any rivers
that are used in this way?
Although water sometimes seems the
greatest blessing that we have, yet it may prove a
curse if it is not looked after. If you give the
water a chance to make gullies in your fields, you
lose not only the water but the best of the soil also.
If you cultivate your fields with care, most of the
water will soak into the ground. If you are a
wise farmer you know also that cultivation of the
soil helps to hold the water, for it cannot escape
through loose soil as it can through compact soil.
Thus if you know how to handle both the water and
the soil, you can, with only a little rain, accomplish
a great deal.
We can, then, hold or conserve
the water, first, by leaving the steeper slopes covered
with vegetation; second, by keeping the soil loose;
and, third, by building reservoirs to hold the floods.
We can make use of the conserved water by carrying
it in pipes or ditches to those regions where it is
needed. We can get rid of too much water by draining
the swamps, and building dikes to protect lowlands
from river floods.
Let us now learn something of the
different uses of water. Every one of our homes
has its water supply. In the city the water comes
through pipes from some distant reservoir. In
the country the homes are so far apart that it is
difficult to supply them in this way. The water
in the streams is often not suitable for drinking,
and if there are no springs near by it has to be obtained
by some other means. Nearly everywhere in the
earth under our feet water can be found by digging
or boring a well. Sometimes we have to go only
a few feet, at other times many hundreds of feet.
This water in the earth, or ground water, is
of very great importance. It enables us to build
our homes where we wish. Spring water is that
which finds its way to the surface through some tiny
crack or fissure in the rocks. How delicious
is the pure, cold water that comes out of the shady
hollow in the hills! You can form in your minds
a picture of the rain falling on some distant mountain,
of its soaking into the ground and finally reaching
the little crevices in the rocks. Along these
crevices it may have crept for days and perhaps years
until at last it found an outlet in some spring.
The great river flows by so quietly
that we often forget in how many ways it is serving
us. It serves not only those upon its banks but
those who live hundreds of miles away and who, perhaps,
have never seen it. It was the first and easiest
means of travel used by our forefathers before there
were any roads or railroads through the wilderness.
It now aids in carrying on trade between different
regions. If large and deep enough, it permits
boats from all parts of the world to reach the very
heart of our country.
Canals might be called artificial
rivers. They serve an important purpose in nearly
level countries where Nature has placed no navigable
river. Although canal boats usually move slowly,
yet they can carry goods cheaper than railroads can.
The Erie Canal, in connection with the Great Lakes
and the Hudson River, makes it possible for us to go
all the way by water from the heart of the continent
to New York City. The Erie Canal has helped make
New York City the greatest city in our country.
The canal across the Isthmus of Panama saves ships
a journey of many thousand miles around South America.
Rivers serve us in yet another way
by affording water for irrigation. A great river
like the Colorado flows through regions of many different
climates. Some rivers become so small in the summer
that it is necessary to build great reservoirs at
their headwaters in order to insure a supply when
the crops need it. But in the case of the Colorado
this is not necessary. The headwaters of this
river are among lofty mountains, where the melting
snows and summer showers make the waters of the river
higher in the early summer than at any other season
of the year. Thus its great delta, the Colorado
Desert, has become the home of many thousands of people.
Another use which we make of rivers
is by putting the water to turning mill wheels.
If you will turn to your geographies, you will find
that nearly all the great manufacturing cities of
our country have grown up around rapids or waterfalls,
where some river tumbles over a ledge of rocks.
Once we had to build our mills close
to the rivers to use the water power, but this is
no longer necessary. Now we build electric-power
plants by the rivers and carry electric energy more
than a hundred miles to any place where we wish to
use it. Electricity made from the distant mountain
waterfall will do any kind of work for us wherever
we carry it. Thus we see that the river works
for us in more than one way. After it has created
power for our factories, it can be turned on to the
thirsty fields, where it will serve us equally well.