<h2><SPAN name="CHAPTER_IV" id="CHAPTER_IV"></SPAN>CHAPTER IV</h2>
<p class="center">(APRIL)</p>
<div class="poem"><div class="stanza">
<span class="i8">The higher Nilus swells<br/></span>
<span class="i4">The more it promises; as it ebbs, the seedsman<br/></span>
<span class="i4">Upon the slime and ooze scatters his grain,<br/></span>
<span class="i4">And shortly comes the harvest.<br/></span>
<p class="right">—<i>Shakespere</i>: "<i>Antony and Cleopatra.</i>"<br/></p>
</div>
</div>
<h3>THE BOTTOM-LANDS</h3>
<p>All that wind was bound to blow up rain. I said so at
the time. And, sure enough, here it is; right where we
want it, at the beginning of April, a month famous for its
rains.</p>
<p>The work of the rains is going to make one of the most<span class="pagenum"><SPAN name="Page_56" id="Page_56">[Pg 56]</SPAN></span>
interesting chapters in the long story of the dust. At least
I hope so. But don't think I intend to tell it all. Why,
it would make a whole book in itself. But you can believe
every single thing I do tell, no matter how it makes
you open your eyes; for, if I've helped it rain once I've
helped it rain a million times!</p>
<h4><span class="smcap"><SPAN name="I._THE_MARCH_DUST_AND_THE_APRIL_RAINS" id="I._THE_MARCH_DUST_AND_THE_APRIL_RAINS">I. The March Dust and the April Rains</SPAN></span></h4>
<h5>HOW RAIN GOES UP BEFORE IT COMES DOWN</h5>
<p>It's this way: You remember how you can "see your
breath," as we say, on a cold morning? Well, that's because
the moisture in your breath is condensed by the cold.
Now as the waters of the earth—the seas, lakes, rivers,
ponds, and so on—are warmed by the sun, the air above
them is filled with moisture, for the heating of the air
causes it to expand and draw in moisture from the water
like a sponge. Expansion makes it lighter also, and it
rises. Rising, it turns cooler, and the moisture condenses
and comes down as rain. Mountains usually have clouds
around them because moist air striking the mountainside
is driven up the slope, cooling as it rises. So rain and snow
fall often in mountain regions, and that's why so many
rivers rise in mountains. The moist air is also condensed
when it meets other and cooler air currents. But right
here is where the work of the dust comes in. For to make
rain you've got to have clouds, and clouds are due to this
moisture collecting around the little particles of dust of
which the air is full. When these little motes of matter
become cooler than the air that touches them the moisture
in the air condenses into a film of water around them.<span class="pagenum"><SPAN name="Page_57" id="Page_57">[Pg 57]</SPAN></span>
Fairy worlds with fairy oceans floating in the sky!</p>
<p>Each of these baby worlds is falling toward the big
world below. But very slowly; only a few feet a day, so
that even if nothing happened it might be months—yes,
years—before it would come to the ground, even in still
air. But when air is very thick with moisture the water
films on these dust particles grow rapidly, and thus increasing
in weight, they fall faster and faster, and finally
strike the earth as raindrops.</p>
<p>But here's another thing that helps. On the way down
two or more raindrops, falling in with each other, will go
into partnership—melt into one—and then they hurry
down so much the faster. That's why the sky grows darker
and darker just before a rain, and why the lower part of a
rain-cloud is the darkest: the little raindrops are forming
into bigger raindrops as they fall.</p>
<h5><SPAN name="THE_LITTLE_ARTISTS_THAT_SHAPE_THE_CLOUDS" id="THE_LITTLE_ARTISTS_THAT_SHAPE_THE_CLOUDS">THE LITTLE ARTISTS THAT SHAPE THE CLOUDS</SPAN></h5>
<p>But the shapes of clouds are supposed to be due to another
thing, the mysterious force we call electricity, and
that other mysterious force we call gravity. Just as the
worlds attract each other by gravity so these raindrops—or
dust grains growing into raindrops—are drawn toward
one another. Here's where Electricity steps in. These
rain particles are full of electricity and when two of these
electrified particles meet in the air—unless they strike one
another in falling, in which case, as I said a moment ago,
they blend into one—they get very close together and yet
keep dancing around one another without touching! It
is this dancing about that makes all those strange and
beautiful and ever-changing forms in the vast picture-gallery<span class="pagenum"><SPAN name="Page_58" id="Page_58">[Pg 58]</SPAN></span>
of the sky.</p>
<p>Of course the wind currents help to change these shapes,
but I'm talking about the original designs.</p>
<h4><span class="smcap">II. The Raindrops and the River Mills</span></h4>
<p>So much for the dust that helps make raindrops; now
for the raindrops that help make dust. This the raindrops
do in several ways. Falling on big rocks or decaying pebbles,
for example, they pound loose with their patter,
patter, patter, any little bits of soil and grains of sand that
have been made by the other soil makers—the sun, the
wind, the lichens, the chemists of the air, and so on. This
soil and these sand particles, if there is already any depth
of earth there, they carry down into the ground. Some
of this soil, with various stops and mixings with other
soils on the way, finally reaches the sea, where it helps to
make the rich limestone soils for the Kentuckies of millenniums
yet to be, by supplying food for sea creatures and
lime for their shells. For these shells become limestone
when the shell-fish are through with them. Mother Nature,
in addition to feeding her big, hungry families of
to-day in the plant and animal world, is always laying by
something for the future. But before it gets back to the
sea, by far the greatest part of the ground-up soil the rivers
carry is spread out in the lowlands in those "alluvial
plains" your geography tells about and that make a large
proportion of the fertile farms of the world. If the raindrops
fall on comparatively barren rock—in the mountains,
say—they carry some of this fresh soil to the mountain valleys
below, and some of it they may spread in bottom-lands
a thousand miles away, where the new soil helps feed<span class="pagenum"><SPAN name="Page_59" id="Page_59">[Pg 59]</SPAN></span>
the plants. The sand grains in it not only help the soil to
get its breath by making little air spaces, but these sand
grains themselves slowly decay and so make more soil.</p>
<div class="figcenter"><SPAN name="imagei071" name="imagei071"></SPAN><div class="figborder"> <ANTIMG src="images/i071.jpg" alt="" /> <p class="caption">WHAT IRRIGATION DOES FOR DESERTS</p> <p class="ctext">It is such land as this, in the arid regions of the West, that irrigation converts from a desert to a garden of abundance. The soil is rich in all the substances that plant life needs.</p>
</div>
</div>
<p>But it isn't alone that they carry away the soil already
made and bury the sand grains. Some of the raindrops
soak into cracks in stones and dissolve the material that
binds the rock particles together, and so get them ready
to give way under the fairy hammers of the next shower
that comes along.</p>
<p>After Nature finally gets an original waste of barren
rock all nicely set with grass and flowers and trees and
things, the raindrops help to make soil in still another way.
Soaking through the decaying leaves, they pick up acids
which are just the thing for eating into rock and crumbling
it into soil. To be sure, the water soaking into the soil<span class="pagenum"><SPAN name="Page_60" id="Page_60">[Pg 60]</SPAN></span>
and coming out of springs carries some plant food away
with it; but it takes it to lands farther down the river valleys,
and more than makes up for what it carries away by
the new soil made by its acids from the rocks, as it soaks
into their pores and runs among the cracks.</p>
<h5><SPAN name="HOW_RAINDROPS_MANAGE_TO_GRIND_UP_THE_ROCKS" id="HOW_RAINDROPS_MANAGE_TO_GRIND_UP_THE_ROCKS">HOW RAINDROPS MANAGE TO GRIND UP THE ROCKS</SPAN></h5>
<p>Moreover, raindrops actually grind up rocks. In order
to do this a lot of raindrops have to get together, to be
sure, and become rivers; but after all it's the raindrops
that do it. There'd never be any rivers if it weren't for
the rains and, of course, the snows.</p>
<p>Well, anyhow, the rivers, besides running other people's
mills, have mills of their own; and millstones. Most of
these stones originally came from mountains and were
brought into the milling business by mountain streams,
with the help of Jack Frost. For the frost not only pries
stones from the mountains and so sends them tumbling
down the slopes, but it keeps edging them along and edging
them along, farther down, after they have fallen. You'd
hardly think that, would you? Yet it's simple enough.
The water in the pores of the rock expands when it freezes
and that makes the whole rock expand, for the time being.
Then when the frozen water in the rock pores thaws out,
the rock contracts, and this spreading out and pulling together,
small as it is, causes the rock to keep hitching along
down the incline; oh, say a fraction of an inch a year.
But still, in the course of the ages, these inches foot up,
and after a while this tortoise-like gait lands the stone—lands
tens of thousands of such stones—in the beds of the
mountain torrents that run along at the bottom of these<span class="pagenum"><SPAN name="Page_61" id="Page_61">[Pg 61]</SPAN></span>
inclines. There they get ground together and so grind
out more soil material, particularly when the floods are on,
with the melting of the snows in spring and the falling of
the heavy and frequent rains.</p>
<div class="figcenter"><SPAN name="imagei073" name="imagei073"></SPAN><div class="figborder"> <ANTIMG src="images/i073.jpg" alt="" /> <p class="caption">AN OLD RIVER MILL</p> <p class="ctext">It used to do a lot of business—this old river mill. Its grist was ground-up rock that helped make fine farming land in the bottoms along the river's course. Such mills, called
"pot holes," are found in the rocky floors of rapid streams, where the eddying current or the
water of a waterfall wears depressions in the bed. Into these depressions stones are washed,
and then by the whirl of the flowing water kept going round and round, grinding themselves
away and grinding out the sides and bottom of the mill.</p>
</div>
</div>
<p>Another curious thing is how the river mills help themselves
to new millstones when they need them. If a river
hasn't enough for its work, it has a way of drawing on its
banks for more. Whenever the stones in its bed get scarce,
so that it can make comparatively little new soil—having
so few stones to grind together—it proceeds to dig its own
bed deeper, since this bed is no longer protected by a
rock pavement in the bottom. This, of course, deepens<span class="pagenum"><SPAN name="Page_62" id="Page_62">[Pg 62]</SPAN></span>
its channel, and so adds to the steepness of the slope of its
banks. Then, owing to this increase in the incline of the
slope, more rocks tumble in, and the "milling business"
picks up again.</p>
<h5>THE GOVERNOR IN THE RIVER MILL</h5>
<p>But there may be too much of a good thing; the rocks
may come in faster than the river mill can take care of
them. Then the river bottom becomes so completely
paved over that the channel stops wearing down at all,
to speak of, and the river remains at the same level until
the rains and the wind and other workers have worn the
banks down and lessened the incline. Then, with fewer
and fewer fresh stones tumbling in, the river gets a chance
to catch up with its work.</p>
<p>It is this ground-up rock stuff of the mountain river
mills, made by the grinding of the running streams all the
way down, that has helped form the rich bottom-lands of
the Mississippi Valley. For uncounted ages, the water of
the Mississippi and its tributaries have been at work, and
by the time you get down into southern Louisiana you come
to the delta where this rich soil has been piled up for more
than 1,000 feet above the bottom of the old Mediterranean
Sea, that used to reach north and south across the country.</p>
<p>You remember the lines, don't you:</p>
<div class="poem"><div class="stanza">
<span class="i0">"Little drops of water, little grains of sand<br/></span>
<span class="i0">Make the mighty ocean and the pleasant land."<br/></span></div>
</div>
<p>Well, this is how they do it; all this that I've been telling
you.</p>
<p><span class="pagenum"><SPAN name="Page_63" id="Page_63">[Pg 63]</SPAN></span></p>
<div class="figcenter"><SPAN name="imagei075" name="imagei075"></SPAN><div class="figborder"> <ANTIMG src="images/i075.jpg" alt="" /> <p class="atext"><i>Courtesy of the Scientific American.</i></p> <p class="caption">THOUSANDS OF FARMS POURED INTO THE GULF</p> <p class="ctext">The Father of Waters is a good farmer in some respects but needs training in others. The
Mississippi's floods, like those of Father Nile, enrich the bottom lands, but the river is apt
to break all bounds and do a lot of damage. Moreover, every year it carries away thousands
of acres of good soil and pours it into the Gulf. How to teach the Mississippi to work in
harness, as the Nile has been taught to do in recent years, is one of the problems which will
require all of Uncle Sam's ingenuity and skill to solve. A good deal of the yearly waste could
be prevented, however, by the various means employed by good farmers.</p>
</div>
</div>
<p><span class="pagenum"><SPAN name="Page_64" id="Page_64">[Pg 64]</SPAN></span></p>
<h4><span class="smcap">III. How the Rivers Act as Bankers for the
Farmers and the Sea</span></h4>
<p>We speak of river banks and the kind of banks that
handle those promissory notes our arithmetics tell about
as if they were entirely different; and so they are, I suppose,
if one just looks at the surface of the thing. But if
we dig into the subject a little we shall see that they are
much alike in the fact that one of the principal businesses
of both kinds of banks is to make loans at interest. Men's
banks loan money, to be sure, while the river banks loan
pebbles, but if it were not for these pebble loans there
would be a mighty sight less money for the banks to loan,
or the farmer to borrow; and the way both banks do business
ought to be a good lesson to certain farmers I know,
who seem to think they can always be cashing checks on
their banks—the farm lands—by hauling away the crops<span class="pagenum"><SPAN name="Page_65" id="Page_65">[Pg 65]</SPAN></span>
without ever putting anything back.</p>
<div class="figcenter"><SPAN name="imagei076" name="imagei076"></SPAN><div class="figborder"> <ANTIMG src="images/i076.jpg" alt="" /> <p class="caption">WHERE THE RIVERS ACT AS BANKERS</p> <p class="ctext">Here is a fine piece of bottom land, one of those "banks" where the rivers keep "checking accounts" for the farmers and the sea; using pebbles for currency, as explained in this chapter.</p>
</div>
</div>
<h5>HOW THE RIVERS PLACE PEBBLES ON DEPOSIT</h5>
<p>The rivers make loans to the soil by depositing pebbles
in the broad bottom-lands along their banks, and then
draw interest by carrying along to other lands, from
time to time, some of the fine rich soil these pebbles help
make by their decay. And the river does this in regular
banking style, "checking out" the pebbles from time to
time, and then depositing other pebbles in their places.
Take the banks and bottom-lands of the Mississippi River,
for example. It has been estimated that it requires about
40,000 years for a pebble to make the journey to the Gulf
from the mountains of a tributary stream where it was
first broken from the rock as a sharp fragment.</p>
<p>The first part of the journey in the mountains is over
steep down grades, and so is comparatively fast, but as the
river gets farther from the mountains, the slope of its bed
becomes less and less, the onward movement is slower and
slower, and more of the pebbles stop to rest. In times of
flood they are carried far away from the regular channel
and spread over the wide flood-plain of the river. Then,
as the flood goes down, they are left buried there under a
coating of mud. So buried, they decay and enrich the soil.
Then the next flood that comes along sweeps the pebbles
with it—checks them out of the bank—but at the same
time carries away not only some of the soil richness which
these pebbles helped to make but the soil material made
by the decay of the vegetation these pebbles thus helped
to grow, such as the roots and blades of wheat and corn
and stubble and chaff left in the fields. That's the interest<span class="pagenum"><SPAN name="Page_66" id="Page_66">[Pg 66]</SPAN></span>
on the loan. Then, when the flood subsides, the pebbles
are again deposited farther along in the river's course,
but meanwhile the same flood has brought fresh deposits
of pebbles from up-stream, and these are left in place of
those taken away.</p>
<h5>RIVER BANKING AND HUMAN CIVILIZATION</h5>
<p>This banking business has been going on for ages and
is a very important part of the history of civilization.
Here and there along the sides of the older and larger river
valleys are found the remains of ancient plains. These
plains are now, many of them, quite a distance above the
level of the stream. This means that they were at one
time the bottom-lands of that same stream, but the stream,
as it dug deeper and deeper into its bed, grew narrower,
and so abandoned its old flood-plains. As savage man
gradually settled down and took to farming, he found these
bottom-lands, with their rich, mellow soil, just the thing
for his crooked-sticks and stone hoes—the only kinds of
ploughs and hoes there were in those days. With such
crude farming tools he couldn't have managed to scratch
a living on any other kind of soil. When the river floods
came along, all these crooked-stick farmers had to do was
to keep out of the way until the floods went down, and
there were their fields all fertilized for them, as good as
new, and they could go on for thousands of years working
the same fields without ever bothering their heads as to
whether they needed any lime or potash or nitrogen, or
anything; for they didn't. The river floods attended to
all that.</p>
<p><span class="pagenum"><SPAN name="Page_67" id="Page_67">[Pg 67]</SPAN></span></p>
<div class="figcenter"><SPAN name="imagei079a" name="imagei079a"></SPAN><div class="figborder"> <ANTIMG src="images/i079a.jpg" alt="" /><br/> <SPAN name="imagei079b" name="imagei079b"></SPAN> <ANTIMG src="images/i079b.jpg" alt="FATHER NILE AND THE MAKING OF EGYPT" title="FATHER NILE AND THE MAKING OF EGYPT" />
<p class="caption">FATHER NILE AND THE MAKING OF EGYPT</p>
<p class="ctext">"Egypt," said Herodotus, "is the gift of the Nile"; and it is true so far as her fertile lands
are concerned. The ancients attributed the annual floods to the god of the Nile, as shown
in that statue of Father Nile in the Vatican. Below is a threshing scene in Egypt painted
by Gerome. The last picture, from a carving in the tomb of an Egyptian noble, shows how
they ploughed and sowed in the Pyramid age.</p>
</div>
</div>
<p><span class="pagenum"><SPAN name="Page_68" id="Page_68">[Pg 68]</SPAN></span></p>
<p>So, in course of time, civilizations such as those of Egypt
and India and Persia grew up, and in further course of
time these civilizations spread into Europe, and finally to
the New World.</p>
<h5>HOW RIVER BANKS GO BANKRUPT</h5>
<p>Now all this is very well, this leaving it to Nature to fertilize
the fields, where everything is just right for it, as it
is along the Nile, but in most lands it won't do it all.
The trouble is that, in raising the grain foods, the ground
must be kept free of grass and weeds, and well ploughed
during the rainy season. But the same rains that water
the fields wash more or less good soil into the streams;
much more than Nature alone can put back. For instance,
down in Italy where, if the old forests were still there, the
rains wouldn't wash away more than a foot of soil in 5,000
years, this soil is being carried into the Po, and by the
Po emptied into the sea so fast—a foot in less than 1,000
years—that if you visit Italy to-day, say, and then go back
in ten years, you'll see bare rocks on many a hillside that
is now clothed in green. On such rocks the soil is already
thin, and in ten years more it is all gone; all washed
away! This thing is going on all around the shores of the
Mediterranean. You are constantly coming on sections
of country that used to be covered with great forests and
prosperous farming communities where the soil has vanished,
and many stretches of barren, rocky land where
hardly a weed can find a foothold.</p>
<div class="figcenter"><SPAN name="imagei081" name="imagei081"></SPAN><div class="figborder"> <ANTIMG src="images/i081.jpg" alt="" /> <p class="caption">WHAT HAPPENS TO THE LAND WHEN THE TREES ARE GONE</p> <p class="ctext">Could anything be more desolate? You can see from this example how vital to our national life is the forest conservation work of our government. Trees, by the network of
their roots, keep the soil from washing away, retain moisture by their shade, and absorb the
water of the rains and the melting snows so that it reaches the rivers and the creeks gradually.
But when the trees are gone the water, unchecked, rushes down the slopes in floods,
washing away the precious soil and leaving them as barren as a desert.</p>
</div>
</div>
<p>"But, what are you going to do about it?" you say. "You
can't change the slope of the hills, can you? And the farmer
has <i>got</i> to plough his land—you just said so yourself."</p>
<p>Yes, he's got to plough his land, to be sure; but so has
he got to have pasture for his live stock. If he hasn't any<span class="pagenum"><SPAN name="Page_69" id="Page_69">[Pg 69]</SPAN></span>
live stock, that just shows what kind of a farmer he is.
Every farmer ought to have live stock. Corn always brings
a great deal more when it goes to market "on four feet,"
as the saying is; and, besides, the live stock give back to
the fields, in the shape of manure, a large part of what they
eat. Now, if you have live stock you must have pasture,
and all land with a slope of more than one foot in thirty
should be used partly for pasture and partly to grow wood
for the kitchen stove, and hickory-nuts and walnuts for
winter firesides. Although the land slopes, the mat made
by the grass roots will keep it from washing away.</p>
<p>"But suppose you lived where there wasn't any land<span class="pagenum"><SPAN name="Page_70" id="Page_70">[Pg 70]</SPAN></span>
to speak of that didn't tip up; in New England, say—what
would you do then?"</p>
<p>Leave the upper part of the slopes in the woods. Then
the water that carries off the soil will not run entirely
away, as it does in ploughed fields, but will creep down
slowly, and, charged with the decay of the woods, help
fertilize the lower lands and change the rocks beneath
them into soil—the acids from the decaying vegetable
matter eating into them.</p>
<p>"But still," you say, "there are farm lands that must be
ploughed even if they do wash away; they're all the land
a man has, sometimes. What then?"</p>
<p>Plough deep. Then the soil soaks up more of the rain
and lets the water pass away in clear springs. This not
only saves soil but, as we have just said, helps to decompose
the subsoil and the bed rock.</p>
<p>Then there's another thing that good farmers do in such
cases. They plough ditches along the hillside leading by a
gentle slope to the natural watercourses; so the water of
the rains, instead of going down the hills with a rush, and
going faster the farther it runs—like a boy on a toboggan—is
caught and checked in these sloping ditches, and much
of the soil it contains deposited before it reaches the streams.</p>
<div class="figcenter"><SPAN name="imagei083" name="imagei083"></SPAN><div class="figborder"> <ANTIMG src="images/i083.jpg" alt="" /> <p class="caption">HOW THE FRENCH PROTECT THEIR HILLSIDE FARMS</p> <p class="ctext">This is how the French peasant keeps the mountain torrents from carrying off his precious soil.</p>
</div>
</div>
<p>The best way of all, of course, is to build terraces, as
they do in the thickly settled parts of Europe. But this
is only profitable for the more valuable crops and not for
ordinary grains.</p>
<h5>SUCH SPENDTHRIFTS OF GOD'S GOOD SOIL!</h5>
<p>My, but it's a shame the way we've wasted soil in this
country. What spendthrifts! To start with—when the
country was first settled—there seemed no end to the fine<span class="pagenum"><SPAN name="Page_71" id="Page_71">[Pg 71]</SPAN></span>
land, and every one could have a good farm for the asking.
All he had to do was to make his wants known to Uncle
Sam and then go out and help himself. What happened
then? Why, what always happens? Easy come, easy
go. These pioneer farmers worked their farms for all<span class="pagenum"><SPAN name="Page_72" id="Page_72">[Pg 72]</SPAN></span>
there was in them; didn't bother, many of them, even to
haul the barn manure into the fields. Then when the old
farm was exhausted they moved off to new lands and did
the same thing over again.</p>
<div class="figcenter"><SPAN name="imagei084" name="imagei084"></SPAN><div class="figborder"> <ANTIMG src="images/i084.jpg" alt="" /> <p class="caption">A HOME IN THE DESERT</p> <p class="ctext">Doesn't look much like a home in the desert, does it? But it is—a lovely home in what the old geographies called "The Great American Desert." In the Sahara oases are few and
far between, but modern irrigation engineering makes oases to order—thousands and thousands
of acres of them!</p>
</div>
</div>
<p>They ploughed on steep hillsides; they allowed gulches
to form, as they will quickly do on sloping ploughed land,
if you don't watch out; they cut away the timber. It's
easy in a hill country like the eastern part of the United
States to have all the good top-soil washed away in twenty<span class="pagenum"><SPAN name="Page_73" id="Page_73">[Pg 73]</SPAN></span>
years after the forests have been destroyed; the good soil
that it probably took 2,000 years to make.</p>
<p>Doctor Shaler<SPAN name="FNanchor_8_8" id="FNanchor_8_8"></SPAN><SPAN href="#Footnote_8_8" class="fnanchor">[8]</SPAN> estimated that in the States south of
the Ohio and the James Rivers more than 8,000 square
miles of originally fertile land had, by this shiftless and
thoughtless way of doing things, been put into such a
state that it wouldn't grow anything; and over 1,500
square miles of this, actually worn down to the subsoil,
and even to the bed rock, so that it may never be profitable
to farm again—at least not in our time—no matter what
they do!</p>
<p>I knew a farmer with a small son to whom he intended
to leave the farm when he grew up, who did things like
that for twenty years. By the time the little boy was old
enough to vote, there was no farm to leave; all the good
part of it was gone.</p>
<p>Serious thing for that little boy, wasn't it?</p>
<p class="center">HIDE AND SEEK IN THE LIBRARY</p>
<blockquote><p>What have burrowing animals to do with the drainage system of
the land? (Keffer's "Nature Studies on the Farm.")</p>
<p>How do angleworms help drain the soil?</p>
<p>How do the forests help make good use of the rain that falls, not
only for themselves but for the rest of us?</p>
<p>How do the rains help to warm the ground in the spring? The
heat they carry into the soil is produced in two ways. The book
mentioned above tells of one of these ways, and Russell's little book,
"The Story of the Soil," tells of another.</p>
<p>Beale's "Seed Dispersal." tells how the raindrops (working together,
of course) help plant maple, elm, sycamore, willow, and
other trees that grow by the waterside, to scatter their seeds.</p>
<p>You'd be surprised what a series of adventures the seeds of a
bladderwort have before they get planted on some new shore, after<span class="pagenum"><SPAN name="Page_74" id="Page_74">[Pg 74]</SPAN></span>
having left the parent shrub. First, they float down-stream, as
you know, but when autumn comes on, what do you suppose they
do? They go to bed. Where? Right in the bottom of the
stream. Then how do they ever get up and get planted on the
shore? Well, you just look it up in that Beale book and see.</p>
<p>Do you know how the rains help to get the mineral food up into
the plant?</p>
<p>And why swamps are such poor producers?</p>
<p>And how the sun acts as a pump for the plant world?</p>
<p>You will find answers to all these questions in Shaler's "Outlines of Earth's History."
and in your books on botany and agriculture.</p>
<p>Russell's book on the soil tells how the ancient Gauls and Britons
used to fertilize their land with marl, and how the tides help to fertilize
England. It's just the reverse of the way Father Nile looks
after Egypt, as you will see.</p>
<p>If you want to read an interesting description of the difficulties
of farming on wet lands, you will find it in this meaty little book.</p>
<p>If you don't know how serious a thing it is to let gullies form in
land, look it up in Shaler's "Man and the Earth" and you will
see.</p>
<p>How do you suppose deserts that get so little rain themselves
could <i>help make it rain</i> in other places? For example, the desert of
Thibet is the chief cause of the monsoon rains that do so much for
India. That part of your geography that explains the circulation
of the air will help you figure this out; particularly with a map
under your eye that shows the relative location of the desert and
the Indian Ocean, over which the monsoon winds blow.</p>
</blockquote>
<hr style="width: 65%;" /><p><span class="pagenum"><SPAN name="Page_75" id="Page_75">[Pg 75]</SPAN></span></p>
<div class="figcenter"><SPAN name="imagei087" name="imagei087"></SPAN><div class="figborder"> <ANTIMG src="images/i087.jpg" alt="" /> <p class="caption">AN EXAMPLE OF MAN'S DEBT TO THE EARTHWORM</p> <p class="ctext">Much of the earth's Maytime bloom and beauty is due to the labor of our humble little brother of the dust, the earthworm; a striking fact which was never recognized until the
great Charles Darwin looked into the matter and wrote a book about him. This picture by
Millet is called "Springtime" and hangs in the Louvre, in Paris.</p>
</div>
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