The daily morning journal and courier. [volume] (New Haven, Conn.) 1894-1907, 1895-09-12

tended 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 resemble
the powders. as they do also in their
worn and rounded shape. The chief
| differences are that the pebbles are so
much smaller, are more smoothly worn,
mcomparably more numerous, more
widely distribute over the earth, and
usually found collected and piled up
| into ridges or heaps. All these charac-
| teristics 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 differ
ent kinds of natural mills in which the
pebble making industry is still carried
on. The first of these is the ice mill
| the same in which the powders We're
shaped. This was evidently in ages
past and over certain extensive re-
gions, the most important Of all agen-
cies employed by nature in grinding up
the solid rocks to particles of all de-
grees of fineness. But it was mill
without a SEPARATOR sort OF prepar-
atory crusher by which immense guam
titles 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 1T are
large quantities of pebbles and other
coarser fragments of rock, ranging in
size from cobblestones up to enormous
powders While part of the finer ma
terial 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 the time
being where the melting glacier drops
it,
The second form of pebble mill is a
very common and familiar one and diff
fers from the first in that it uses flow
ing water instead of ice in carrying on
the grinding process. Almost every
body has witnessed it in operation,
though unfortunately many people fail
to have, their eyes open to see and re-
cognize the ordinary processes by
which nature working tirelessly
through countless ages, has accom-
plished 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 a pave
ment of pebbles. The farther UP the
stream we go the larger and more nu-
merous, and also the less smoothly
worn, we find the pebbles. These bits
of rounded rock are not placed in the
bed of the stream simply to prevent it's
cutting too deeply into the soil, though
they do often serve that useful purpose
most admirably. They are kept slowly
on the move. AT every time of freshet
they are rolled over, rubbed together
and carried a little farther down the
stream. In this way they are ground
down year by year by.a process so slow
as to almost avoid detection, but SO
ceaseless as to accomplish marvels
when time enough has been given
To find the place where the rock ma
: terial is furnished and the grinding
process begins 1t will be necessary to
: follow up the stream to its origin, per-
) haps among the mountains or high
: rocky hills. Here we find the noun
tain torrent frequently INSTRUCTED nv
large angular blocks of rock which
| have fallen into its channel. Some Of
| these may remain for centuries immoy-
able by the stream, but there are all
ways many that are small enough to be
tumbled downward, especially where
, the descent is steep. The pounding.
grinding and rubbing process thus ever
beginning goes never endingly on.
And it is often greatly aided, especial
ly in its upper and earlier course. nv
the disintegrating action of the frost
upon the rocks.
The third form Of mir employed by
nature in the production Of pebbles is a
very powerful and effective one. and
the one that has been in operation the
longest of all. 1t is the waves of the
seashore dashing against the rocks.
The effectiveness of this powerful
/, agent ds something almost incredible
: The lashing waves, armed as they usu-
: ally are with gritty sand, cut away
t even the solidest rock This constant
e undermining Of the projecting cliffs
' ranged along the more than one hun
: dred thousand miles or seacoast as well
as along the shores Of all the larger
:, lakes results in an incalculable amount
, | of broken rock falling in the course OF
, centuries into the waters beneath
. With these loose fragments once al
/ their mercy the waves begin upon them
= a. 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 tbs
| name Of pebbles. The pebbles that
! have been thus manufactured and
heaped up along the ancient seashores
are what now constitute many Of our
gravel beds, the sea having meantime
retreated many hundreds of, miles, il
L