Daily Kennebec journal. [microfilm reel] (Augusta, Me.) 1870-1975, 1895-08-22
ORIGIN OF PEBBLES.
tow NATURE MADE THE WORLDS
BEDS OF GRAVEL.

Which Carry on the Industry-Flowins
Water, Grinding Ice and Dashing Sea
Water at Work Upon Masses of Rock.
There is not much fertility in a gravel
bed, and yet many q farmer has found that
a barren ridge of this kind, besides fur
nishing him an ideal site for bank barn,
has proved one of the most profitable
patches on his entire farm. Neither is it,
chiefly, in the price per load received for
the contents of gravel pit that its prac-
teal value consists though that may be
far from an inconsiderable item. Though
gravel cannot be used as a fertilizer to in
crease the products of tho surrounding
land it may add greatly to the value of
such products by making a permanently
passable road leading to a convenient mar
ket. This is the purpose for which nature
appears to have intended it. Not for the
wagon road alone but for railroad ballast
as well, nothing more satisfactory has ever
been devised.
AS of the scattered powders, so of these
piled up pebbles, the question must often
arise, Where did they all come from? That
they must have come from various places
is evident, for they are made up Of various
kinds of rock. In this respect they resem-
Bile the powders, as they do also in their
worn and rounded shape. The chief differ
ences are that the pebbles are so much
smaller, are more smoothly worn, incom-
parably more numerous, more widely dis
tribute over the earth, and usually found
collected and piled up into ridges or heaps.
All these characteristics indicate that these
bits OF stone have undergone long process
of grinding and polishing. But do We
know of any process of nature by which
this work could have been done?
Yes, we find even now in operation and
open to our inspection three different kinds
of natural mills in which the pebble max
ing industry Is still carried on. The first
of these is the ice mill-t.lc same in which
the powders were shaped. This was evil
IDENTIFY in ages past and over certain OK
tensive regions, the most important of all
agencies employed by nature in grinding
up the solid rocks to particles of all degrees
of fineness. Eut it was mill without a
separator--a sort of preparatory crusher
by which immense quantities of materials
were fitted for the more ready use of other
agencies. How this preparatory work was
done may be learned through the samples
still furnished for our observation and
study. Beneath every living glacier Of
any considerable extent there is found an
accumulation of rocky material the mass
of which has been crushed and ground to
powder in the form of sand and soil while
mingled with it are large quantities Of
pebbles and other coarser fragments of
rock ranging in size from cobblestones up
to enormous powders While part of tho
finer material is carried onward from the
mouth of the glacier by the outflowing
stream of water, the bulk of all the grist,
both coarse and fine, remains for tho time
being where the melting glacier drops it.
| The second form of pebble mill is q very
common and familiar one and differs from
the first in that it uses flowing water i'm
stead of ice in carrying on the grinding
process. Almost everybody has witnessed
it in operation, though unfortunately
many people fail to have their eyes open
to see and recognize the ordinary processes
| by which nature, working tirelessly
through countless ages has accomplished
such extraordinary results. In all regions
except those that are very fit or level the
beds of the streams are apt to be found
covered with q pavement of pebbles. Tho
farther up the stream we go the larger
and moro numerous, and also the less
smoothly worn, we find the pebbles These
bits of rounded rock are not placed in the
bed of tho stream simply to prevent its
cutting too deeply into the soil, though
they do often serve that useful purpose
most admirably. They arc kept slowly on
the move. At every time of freshet they
are rolled over, rubbed together and carried
q little farther down the stream. In this
way they are ground down year by year
by process so slow us to almost avoid de-
lection, but so ceaseless as to accomplish
marvcls when time enough has been given.
To find the place where the rock ma
terial is furnished and the grinding proc
css begins it will be necessary to follow
up the stream to its origin, perhaps among
the mountains or high rocky hills. Hero
we find the mountain torrent frequently
INSTRUCTED by largo angular blocks of rock
| which have fallen into it's channel Some
| of these may remain for centuries immov-
| able by the stream, but there are always
many that ara small enough to be tumbled
| downward, especially where the descent is
steep. The pounding, grinding and rub
| bling process thus ever beginning goes
never cndingly on. And it is often great
ly aided especially in its upper and earlier
course, by tho disintegratng action of tho
| frost upon the rocks.
The third form of mill employed by M.
ture in the production of pebbles is very
| powerful and effective one, and the one
| that has been in operation the longest of
| all. 1t is the waves of the seashoro dash
| ing against the rocks. The effectiveness
| of this powerful agent is something almost
| incredible. The lashing waves, armed as
| they usually are with gritty sand, cut
| away even the soldest rock. This con-
slant undermining of the projecting cliffs
| ranged along the more than 100, 900 miles
of seacoast as well as along the shores of
| all the larger lakes results in an incalcula
| BILE amount of broken rock falling in the
course of centuries into the waters be-
meath. With these loose fragments once at
| their mercy the waves begin upon them
pounding and grinding and washing that
| has never been relented since waves and
| rocks began. The result is the wearing of
| countless millions of rock fragments into
| the smooth and rounded forms to which
we give the name of pebbles. The pebbles
that have been thus manufactured and
heaped up along the ancient seashores arc
what now constitute many of our gravel
| beds, the sea having meantime retreated