Coal (?), n. [AS. col; akin
to D. kool, OHG. chol, cholo, G.
kohle, Icel. kol, pl., Sw. kol, Dan.
kul; cf. Skr. jval to burn. Cf. Kiln,
Collier.] 1. A thoroughly charred,
and extinguished or still ignited, fragment from wood or other
combustible substance; charcoal.
2. (Min.) A black, or brownish
black, solid, combustible substance, dug from beds or veins in
the earth to be used for fuel, and consisting, like charcoal,
mainly of carbon, but more compact, and often affording, when
heated, a large amount of volatile matter.
☞ This word is often used adjectively, or as the first
part of self-explaining compounds; as, coal-black;
coal formation; coal scuttle; coal ship.
etc.
☞ In England the plural coals is used, for the
broken mineral coal burned in grates, etc.; as, to put
coals on the fire. In the United States the singular in a
collective sense is the customary usage; as, a hod of
coal.
Age of coal plants. See Age of
Acrogens, under Acrogen. --
Anthracite or Glance
coal. See Anthracite. --
Bituminous coal. See under
Bituminous. -- Blind coal. See
under Blind. -- Brown coal, or
Lignite. See Lignite. --
Caking coal, a bituminous coal, which
softens and becomes pasty or semi-viscid when heated. On
increasing the heat, the volatile products are driven off, and a
coherent, grayish black, cellular mass of coke is left. --
Cannel coal, a very compact bituminous
coal, of fine texture and dull luster. See Cannel
coal. -- Coal bed (Geol.),
a layer or stratum of mineral coal. -- Coal
breaker, a structure including machines and
machinery adapted for crushing, cleansing, and assorting
coal. -- Coal field (Geol.), a
region in which deposits of coal occur. Such regions have often a
basinlike structure, and are hence called coal basins. See
Basin. -- Coal gas, a variety
of carbureted hydrogen, procured from bituminous coal, used in
lighting streets, houses, etc., and for cooking and heating.
-- Coal heaver, a man employed in carrying
coal, and esp. in putting it in, and discharging it from,
ships. -- Coal measures. (Geol.)
(a) Strata of coal with the attendant
rocks. (b) A subdivision of the
carboniferous formation, between the millstone grit below and the
Permian formation above, and including nearly all the workable
coal beds of the world. -- Coal oil, a
general name for mineral oils; petroleum. -- Coal
plant (Geol.), one of the remains or
impressions of plants found in the strata of the coal
formation. -- Coal tar. See in the
Vocabulary. -- To haul over the coals,
to call to account; to scold or censure. [Colloq.] --
Wood coal. See Lignite.