Ellsworth American. [volume] (Ellsworth, Me.) 1855-current, 1893-02-02
The Soil.

LIZ SOiit
II we examine some soil with a mi
roscope. we shall find that. while il
Contains some other substances of a
'i'ferent nature, large part Of il is
composed If finely divided PARTICLES OF
rock. These are generally Of a similar
nature to the larger rocks that are
|,cattered through the soil, and have
been produced from large rocks by Tho
grinding and crumbling forces of ma,
lure.
The greater part OF our present soil
however. was not formed directly out
IF the original rocks of the first crust
If the earth. The soil formed bv tie
itirst crumbing of the original rock,
generally soliditied, or petlted, int,
rock again. and this process Of crum
Ibling and solidifylng continued througl
several alterations until our presen
soil was formed.
Nearly all the present rocks were a
some time soil. Conglomerate stones
sometimes called "Puddings stones.
|are examples of an ancient soil, con
Itainng stones of different kinds, which
has been transformed into solid rock
Sandstone was once a bed OF sand.
Specimens OF rocks from the origi
nal crust are now - be found only il
A few scattered localities in those see
lions which first appeared above water
where, by virtue of their elevated posi-
ton, they have partly escaped tn
forces that would tend to destroy them
Tie process Of rock making is sill
going on There is often to be found
beneath the surface soil, stratum o
hard pan" through which it is diff
Icult to penetrate. This is gradual!
becoming solidlfed by the action o
chemical forces, and at some time il
| the distant future will become stone.
The chief agencies in nature which
have done the work of grinding rocks
and preparing the soil of the eartl
are -
!. The Atmosphere.-Ncarly al
rocks, when exposed to the atmosphere
above ground. undergo chemica
changes upon their surface by whici
portions are continually crumbing anC
falling off. This effect upon some rock.
will cause them to waste away 10 {
very few years. while with others tn,
process is much slower.
Some varieties of sandstone are found
lear the surface, SO much affected by
the atmosphere, which has reached
them through the porous soil, as TO b,
easily crumbled into powder.
The most enduring kinds of marble
used for erecting monuments. are gen
orally covered with fine marble dust
Showing that even they are not exempt
from the universal tendency
,. Running Water.-With every
shower aud rain storm, and with the
melting SHOWS in spring-time, streams
and brooklets are constantly wearing
away the rocks, and washing away sol
from the sides of hills and mountains
and carrying it into the rivers below
As the current OF the river becomes les;
rapid, this soil settles, forming depos.
its on the banks Of the river al its
mouth, or on the neighboring shores OF
the ocean.
When the streams and rivers are
much swollen, thew wash out and beal
away many rocks in their swift eur.
rent. AS these are rolled and tumblec
|one upon another, they are ground into
soil, which is added to the general de.
post. The mountains and hills are
thus gradually carried away to fill the
valleys below, and to extend the coast.
|of the continent. The rich alluvial lands
in river valleys have been formed il
this way.
3. The Ocean.-The movements OF
water on the shores of the ocean pro-
|duce an effect similar to that of rivers.
The flow and ebb of the tide, and the
breaking of waves on the beach grind
rocks into sand, or wash up shells from
deeper water, grinding them into fine
powder. This process has been going
|on since land first appeared above wa
ter. forming the origin of our Continent.
The ocean has been continually form
ling beds of sand and mud on or near
fits shores. These have been raised
above the surface, as the waters have
|receded, and in many cases have be-
come consolidated into rock. Sandstone
and limestone have been mostly pro
|duced in this manner, the former from
the sand beds, and the latter from mud
formed by the grinding of shells. A
similar effect has been produced BY
Large lakes, some of which have become
entirely dry, leaving deposits of sand !,
lime, or other mineral matter.
4. Ice.-Ice forming in the crack !
and crevices of rocks, year after year,
tends by its expansion to burst the
rocks or open crevices, thus admitting
the atmosphere, and Fastening the
work Of crumbling.
Minute particles are also detached
from the rocks by the freezing and
of the moisture upon their sur
face. If a number of clean stones are
placed in pail of pure water, and the
water is allowed to freeze and thaw sew.
eral times, there will be found per-
,eptible quantity of fine particles at the
bottom.
But the greatest effect Office in form.
ng soil, and changing the face of mas
lure, has been through glaciers.
In high, mountainous regions, and
n cold laIitudes, snow steadily accumu-