The Birmingham age-herald., 1913-06-18
BY DICK WELLS

percentage of volatile hydrocarbons is
very high. is believed to be of DIFF
ferent origin from other Goals.
Ignite, or brown coal, is brown to
black in color though the powder Is
always brown. 1t often shows its vege-
table origin, boring stems and other
plants, which look to be in an unde-
composed state. The luster is change
able for the type, the specific gravity
being to 1.5, some kinds even float
ing ON water. Lignites burn easily with
very dirty smoky flame, crumbles cas-
lily and generally contain a high per-
centage of water and slack or even
mud on long exposure.
Different Kinds of Coal
Bituminous or soft coal is black the
powder is black, and the luster is resin
Gus or dull. Its specific gravity is 1.25
to Ia. It has less water than Ignite
and is much harder. For that reason
it can stand shipment much better than
| the soft Ignite. Bituminous Goals are
subdivided according TO their properties
or uses into coking, free burning,
smokeless, gas coal and SO forth. Cox
If they are low in ash and sulphur
they are used as forging Goals. and for
making coke and gas. Camel coal is
black or brownish and has dull lus-
ter; it does not soil the hand, and does
not show traces of vegetable origin
1t burns with an easy flame, is easily
ignited and is often used in the CRATE
and for household purposes. But its
greatest use is enriching gas made
from other Goals. 1t is mined in the
United States at Cannelburg, Ind, and
in the Jellco district of Kentucky.
Anthracite is also a black coal with
black powder which does not soil the
fingers. The specific gravity is 1.S to
LIS. 1t is hard to kindle but it is
very valuable nevertheless owing to
the high percentage of fixed carbon it
contains. 1t burns with hardly any
smoke and with one of the most in
tense heats made by any of the classes
of coal. 1t was formerly much used
in the country for the smelling of iron
but its chief use now is for household
purposes and in the CRATES. The less
water, ash and sulphur a coal contains
the better the coal and good coal should
not contain over to z per cent of ash
and Z per cent of sulphur.
Location of Coal Fields
North America, Asia and Europe con-
tain the great coal fields of the world.
In southern Africa, in Australia and in
New Zealand are deposits of import
ance. Only small and disconnected areas
q re L in,
only mines worked on large scale are
in Chill. AS to Asia, the coal fields of
China are vast and of great import
ance. but they are practically undevel-
oped. Coal is abundant in Borneo and
Burma and the output is increasing,
especially from Bengal.
The United States, Great Britain and
Germany together produce about 80 per
cent of the total amount of coal mined
in the world.
The mining consists IN getting out
as little dust as possible. The princi-
pal gases found In a mine are carbon
dioxide, heavier than air. suffocatine
but not inflammable, called choke damp
by the miners; carbonmonoxide. pois-
onous and inflammable which Is the
dreaded white damp Of the mines; C
Fl. 4, which is known as marsh gas
this gas being light. n-poisonous bui
inflammable, its chief constituent being
flredamp; also but less important, sulph
uretted hydrogen, which Is poisonous
and inflammable but easily detected BY
Its odor OF all these gases the marsh
gas often given off in large quantities
is the cause of the worst mine disas-
ters. A mixture of marsh gas and all
explodes violently when they come to
gether in the proper quantities and i
brought into contact with flame. Goa
dust in the air makes very mucf
smaller proportion of marsh gas.
Safety Device Used
| To be able to work in the mines
when these explosive gases are presen