What is "blind coal"

Blind \Blind\, a. [AS.; akin to D., G., OS., Sw., & Dan. blind, Icel. blindr, Goth. blinds; of uncertain origin.]

1. Destitute of the sense of seeing, either by natural defect or by deprivation; without sight.

   He that is strucken blind can not forget The precious treasure of his eyesight lost.
   --Shak.

2. Not having the faculty of discernment; destitute of intellectual light; unable or unwilling to understand or judge; as, authors are blind to their own defects.

   But hard be hardened, blind be blinded more, That they may stumble on, and deeper fall.
   --Milton.

3. Undiscerning; undiscriminating; inconsiderate.

   This plan is recommended neither to blind approbation nor to blind reprobation.
   --Jay.

4. Having such a state or condition as a thing would have to a person who is blind; not well marked or easily discernible; hidden; unseen; concealed; as, a blind path; a blind ditch.

5. Involved; intricate; not easily followed or traced.

   The blind mazes of this tangled wood.
   --Milton.

6. Having no openings for light or passage; as, a blind wall; open only at one end; as, a blind alley; a blind gut.

7. Unintelligible, or not easily intelligible; as, a blind passage in a book; illegible; as, blind writing.

8. (Hort.) Abortive; failing to produce flowers or fruit; as, blind buds; blind flowers.

   Blind alley, an alley closed at one end; a cul-de-sac.

   Blind axle, an axle which turns but does not communicate motion.
   --Knight.

   Blind beetle, one of the insects apt to fly against people, esp. at night.

   Blind cat (Zo["o]l.), a species of catfish ( Gronias nigrolabris), nearly destitute of eyes, living in caverns in Pennsylvania.

   Blind coal, coal that burns without flame; anthracite coal.
   --Simmonds.

   Blind door, Blind window, an imitation of a door or window, without an opening for passage or light. See Blank door or Blank window, under Blank, a.

   Blind level (Mining), a level or drainage gallery which has a vertical shaft at each end, and acts as an inverted siphon.
   --Knight.

   Blind nettle (Bot.), dead nettle. See Dead nettle, under Dead.

   Blind shell (Gunnery), a shell containing no charge, or one that does not explode.

   Blind side, the side which is most easily assailed; a weak or unguarded side; the side on which one is least able or disposed to see danger.
   --Swift.

   Blind snake (Zo["o]l.), a small, harmless, burrowing snake, of the family Typhlopid[ae], with rudimentary eyes.

   Blind spot (Anat.), the point in the retina of the eye where the optic nerve enters, and which is insensible to light.

   Blind tooling, in bookbinding and leather work, the indented impression of heated tools, without gilding; -- called also blank tooling, and blind blocking.

   Blind wall, a wall without an opening; a blank wall.

Coal \Coal\ (k[=o]l), 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. Note: 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. Note: 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 Brown 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.)

   1. Strata of coal with the attendant rocks.

   2. 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.

n. Coal that burns without a flame; anthracite coal.