The Cambria freeman. [volume] (Ebensburg, Pa.) 1867-1938, 1879-02-14

/ distinguish from true coal, and Which,
/ therefore, must be true coal. "Iu Holland,
! Denmark and Sweden the thick deposits of
peat are separated into distinct beds by
| strata of sand and mud, giving the best
| possible clue cidation of the process Of STRAIT
| ification of the real measures (Lesque
/ reux.) For their formation these bogs re-
| quire basin rendered impermeable 10y a
! substra:um Of clay and an active growth of
/ aquatic or semi 5erial plants, having their
roots ia water, while their branches and
leaves expand on the surface thereof, or
rise in the air above it, constantly growing
| In The same place, whose debris, falling
year after year, is heaped up and preserved
against atmospheric decomposition by stag
nant water or great humidity in the air.
It was during the Carboniferous epoch,
when our principal and most valuable seams
Of coal were deposited, that all these favor
able circumstances were in their highest
development. For dense vegetation we
also want warm, moist, and equable eli
mate. aud air more or less charged with
carbonic acid gas, as that is the food of
plants, Gust as the oxygen gives life to a
man, though it is poisonous to warm
blooded animals, it being impossible for
such to live in an atmosphere containing
more than about one per cent. of it.
Daring the CarbonIferous age of the
earth's history the water covered much
more of an area than it now does, and por-
tions of the continents were so little raised
above its surface that a slight elevation or
depression would change them from marsh
es and lagoons into dry land, or sink them
below the surface of the sea. When air
passes over, or rests on oceans, or lakes or
rivers, etc, it becomes laden with vaDor,
whose influence is very potent, as its pow
er of absOlyIng or retaining heat is
thousands of times, greater than that Of
air. Hence, as the ocean was so largely
preponderant, there was an atmosphere
heavily charged with moisture which, in
time, was favorable to a warm and equable
climate. IN fact, the want of annual rings
in carboniferous plants proves that there
was no winter, and, as the same coal plants
grew at the same time in Europe and
America, the same climate must have pre-
vailed. The air was also charged with
carbouc acid, for there are no fossils (Which
Prof. Huxley so beautifully says are the
labels that an Almighty hand has put apon
the specimens in Natures museum in this
or any other earlier formation of warm
blooded animals
Iu these circumstances, therefore, there
exist the most advantageous conditions for
the rapid and continuous growth of vege-
tation, and judging from the fossils there
of, il must have gone on with density and
luxuriance that we'll nigh surpasses con
ceptiOn. Floating vegetables first made
their branches and leaves on the surface of
the water, and filing the basin or lagoon
with their de 5riS, :hus forming a support
for the more arla vegetation, compared
with which anything in our day Of the same
species, in respect to size and quantity,
fades into insiguificence.
The exuberant growth of the tropics is
astonishing to US ; but it is as nothing
when we contemplate that of the coal era.
For example : Equisetum, the horsetail
flag, with us is never more than half an
inch in diameter, while in the coal rocks
gigantic reeds of this kind were as much
as fourteen inches in diameter. Living
club MOSES even in our tropics attain no
great height, but there they are rs thick as
mans body and sixty feet high. Our
ferns are Of insignificant size, but in those
olden days they raised their feathery foliage
to a height of sixty feet and upward
There are others that grew to the same
wonderful proportions and as they fell
others sprang up, and thus the ''heapiug"
process continued until Nature caused some
subsistence of the ground the water closed
over 1t all an6 the currents deposited mud
and sand upon it if the former, stratum
of slate was the result; if the latter, a
stratum of sandstone. When this subsi- /
dence ceased, fresh growths sprang up and .
a new deposit was formed to sink and be
covered in lis turn and as often as these
periods of rest ard submergement were re-
peated, SO did a new coal bed come into
existence, and in this is simple ratioHalex- /.
PLANTATION why the coal measures have
more than one seam in them.
If, on the other hand, an elevation took /
place, the roots of the plants were deprived
of their moisture, and they not only ceased
growing, and the deposit accumulating,
but the rain and surface drainage gradually +.
carried the latter away, and, as it floated
off, it became mixed with any earthly mat
ter which the waters may have in mechau +
ical suspension and when it was finally
deposited in some lagoon OF overspread
other formations, it ultimately made an in.
ferior coal or slate, according to the pre-
ponderance of The mud which was with it.
Thus we can understand one of the causes
why some regions have more seams than
others.
When the deposit was covered up, as be-
fore explained, a gradual decomposition
took place, which consisted in an evolution
of a portion of the carbon, and most of the .
hydrogen and oxygen, in the form Of water
and gases from the woody tissue, leaving n
larger and larger percentage of the carbon
OF the plant behind, while the increased
pressure of the nccumulating strata above
served to compress and sol idify the mass.
But before this qualification took place, as
Liebig has proved by direct experiment, in
the process of slow decomposition of vege
table matter in water, softening occurred
and is to this that we must ascribe the fact
that no delicate fossils are ever found In