The Anderson intelligencer. [volume] (Anderson Court House, S.C.) 1860-1914, 1888-05-17
What Makes 1t Rain {

How often on shoaery days little folks
here asked themselves or their elders
"What makes it rain ?" and how very
seldom they have been able to get g sat
isfactory reply Sometimes those who
know have no time to tell, and oftener
those who have plenty Of time do not find
it quite convenient to explain. Let ua
sit down and talk it over, and see if We
can discover, first, why it rains at all
and then, when 1t does rain, why it does
not rain in the same way over the whole
earth.
Did you ever stop to think, when you
looked out of the window and saw dull,
gray clouds from which the rain was
steadily pouring, and which seemed to
shut in the world all around, that, in
reality, they extend over very small
part Of the country; that somewhere else,
perhaps only twenty or thirty or 8 hun.
miles away, the sun was shining, and all
was bright and beautifulf This is really
the case. For storms, however long and
dreary, do not extend over many miles,
and though it always is raining at some
place in the world, yet always and at the
same time it is pleasant somewhere else.
Now let us see Why this is. Suppose that
on warm Summer afternoon we we're to
bring pitcher of clear, cool water, fresh
from the we'll, and to place it on tha
table in the dining room. Now, no mats
ter how carefully we may have dried the
pitcher before bringing it in, we shall
discover, if we watch closely, that the
outside soon becomes wet or misty ; and
that the mist grows heavier, and then
gathers into drops, and perhaps even
runs down the pitcher to the table. Now
where does this water come from? Not
through the sides of the pitcher, that is
but from the air. We can.
not see it, perhaps, but still it is there, in
the state of vapor. How came it there2 2
Did you ever notice, after rain, how in
a short time the puddles became dry, and
how the moisture disappeared from the
grass and leaves, as soon as the sun shone
out and the wind blew7 Or did you ever
notice that if you left pan of water out
of doors the water each day grew less
and less, until all was gone and the pan
was dry?
All the water that was in the puddles,
on the grass and leaves Except that
which soaked into the ground) and in the
pan, was taken up as vapor into tho air
has "evaporated," as we say. The same
thing happens when water boi]s, only it
then evaporates more rapidly, and we can
see the yapor arising as steam. If you
live near a-river, or in country where
there are brooks, perhaps you can see
this evaporation actually taking place.
Get up early some morning, before the
sun rises, and look out toward the river.
You may see long line of mist or fog,
like a big, white cloud, hanging over the
water. Now this mist is only the water
evaporated from the river, and is just
now visible as fog because the air is cool.
After the sun has shone, the air becomes
warmed and the fog disappears, but the
goes on nevertheless. In
deed, it is going on continually, and all
over the earth 80 that if the water we're
not returned to US as rain, snow and dew,
all the oceans, lakes and rivers would in
time dry up aud disappear. All the
trees, grass and plants would then wither,
and our beautiful land would become as
dry aud parched as the great desert of
Sahara.
Having now learned how the water
is drawn into the air, let us see how and
why it comes down again as rain or snow
or dew. There is singular thing about
this moisture, which is this: the air will
hold only certain quantity of it, and
that quantity depends upon the tempera-
ture of the air. But warm air always
holds more than cold so, however warm
the air may be, or however much mois.
ture it may contain az invisible vapor, we
have only to cool it enough and the
vapor condenses, as we say; that is, it
becomes visible, first as fog or mist, and
then as drops of water, such as we see on
the pitcher. And the reason we see
white fog rising at night after the sun
goes down is only because the water,
which has been evaporatiDg all day and
going up into the air as invisible vapor,
becomes condensed to fog by the cooling
of the air when the sums heat is with
drawn. When the sun rises the fog dis
appears, but the vapor still ascends, and
when it reaches the attitudes where the
air is always cool, it becomes condensed
again as fog, ouly~ it is then called
"clouds."
And if it becomes condensed enough
to form in drops of water, they fall, and
it "rains," or perhaps it SHOWS, for SNOW
is but frozen rain.
Thus ne have learned that rain is
caused by the cooling and condensation
ofthe moisture in the air. Bearing this
in mind, let US study the surface of oul
country and see why the rain does moi
fall equally on all parts of it, instead o:
falling very abundantly in some places
as in New England and many ofthe Gull
States, and very sparingly in many parts
of the West, as in New Mexico and Ari
zona. The winds which blow to this
country from the South and the East
being warm tropical winds, can hole
much moisture and are full of this in
visible vapor Of water which they have
taken up from the Gulf of Mexico ant