The Camden chronicle. (Camden, Tenn.) 1890-current, 1902-05-02
HOW COAL WAS FORMED
HhDE IN THE EARTH's LAeoRATo ET
FROM VEGETABLE MATTER.

Coal was manufactured In the earth's
laboratory from accumulNtlons Of veg
etable matter Of that there Is no doubt
AS TO the precise manner IN which the
manufacture took place there are DIFF
ferent theories The trees, ferns aud
Inosses OF that Tar Off geological period
called the carbonlferous (coal-bearing)
era, provided the material Of which
the coal was made. But by what proc
ess did nature produce the vast accu-
mutations Of vegetable matter which
were necessary TO form, after extreme
compression, the deep beds Of coal
which arc now being mined2
In the forests with which we arc
familiar there Is no such accumula-
ton OF vegetable matter The roots Of
the trees do not lave 10 go down far
before they reach the earth. If the
trees in these forests were to fall on
top OF the mould now, and both to-
gethcr were to come under the pres
sure OF everything earth, and be grad
ually converted into coal, in many
cases there would be but a very thin
layer of coal too thin to be worth
working. And yet forests may have
been growing on that same land for
thousands Of years.
Why is there not q larger accumu-
lation of vegetable matter? Because
the trees, or ferns, or MOSES have
decayed as fast as they died. A fallen
tree rots away in n few months or
years according to the circumstances.
That is as much as to say that it is
slowly burned. And this burning, or
oIygcnation, or rotting takes place at
n great enough rate 10 prevent the
formation Of any great depth Of veg
etable mould.
The conditions most favorable to this
process Of decay are found in places
where rains and a drying sun alter
nate The wood of a boat goes fastest
at the waterline The conditions ia
vorable to the preservation Of wood
and therefore to the accumulation OF
matter for coal beds are found where
wood is kept wet all the time after it
has fallen to earth. If a forest grew
in a bog, then there might be many
generations Of trees fall one on top
Of another without decaying The wa
ter into which the trees would sink
would preserve them. And there, too,
there would often be found a luxuriant
growth Of vegetation among the trees
to fill up the interstices between. And
it is found that it is just the kind of
plants that resist decay best under
water that have gone to make up
coal.
Though on dry ground, and in eli
mates where wood decays fast, there is
no deposit such as might be the fore
runner Of a coal bed, we may see in
many parts of the country in swamps
and boys vast accumulations of the
necessary material.
In some peat bogs, for instance, the
peat is yards deep, and a very large
percentage Of this peat after the water
is taken out is carbon. II there is no
infltration from higher ground such
as would carry lime and other salts
into the peat, there is in such a bed
the possibility of good coal at some
future age of the world.
We VIII suppose that, after q goodly
thickness of peat has accumulated
fbo fn1r lov. 4Ov, !,
beds Of stone and Of drift form on top
of the peat. After ages the thickness
of these superposed layers of mineral
matter will be great and the pressure
which they will exert on the peat be.
low them will be enormous. The pres
sure, varying at different times through
earth movements, will generate heat
and the heat will alter the character
of the coal somewhat, distilling of
different gases and hydrocarbons.
There is abundant evidence that al
different stages in the formation of The
carth's crust large areas of land sub
sided and were covered by the ocean
sometimes for long period, and tina
in some cases before the land rose
again what had been the surface wa
covered with drift gravel or with {
layer or perhaps more than one laye
of sediment which afterward turned
into rock.
The character of coal, whether hare
or soft whether plentiful in ash o
comparatively free from ash, depend
partly upon the nature of the vegetabl
matter Of which it was made-chief,
perhaps on the nature Of the sap 0
the plants; but partly also it depend
on the circumstances under which tn
beds have been formed, and whethe
much mineral matter had becom
mixed with the vegetable mould, o