400 GLOSSARY. 



coal : it is, however, never pure, and has a smell duo to the presence of 

 hydrocarbons. 



Black-ends. Inferior coke, generally found on the outside of 

 charge. 



Black trucks. A box-shaped truck, with end door, so-called because 

 it is made black with tar. 



Bio ire r. A sudden stream or outburst of fire-damp from a face of 

 coal. 



"Blown-out shot. A shot that has blown out the tamping of a hole 

 without breaking the coal or rock as intended. 



Bobbin. A catch placed between the, rails of the up-line of an 

 incline to stop any run-a-way trucks. It consists of a bent iron bar, 

 pivoted in such a manner so that the down-hill end is slightly 

 heavier than the up-hill end, which is capable of being depressed by 

 an up-coming truck, but rises above the level of the truck axle t as 

 soon as the truck is past. 



Bord. A common bord is a long chamber driven at right angle* 

 to the facing. A narrow bord is four yards wide or less. A wide 

 bord is over four yards in width. 



B<>rd course. A direction at right angles to the main cleat or 

 facing, i.e., the length of a bord. 



Bord and pillar. A system of mining coal in which it is first won 

 from bords or chambers, the roof being temporarily supported by pillars 

 of coal left between them, but which are in most cases subsequently 

 extracted. 



Bottom gas. A mixture of explosive gases collected in depressions 

 in coal mines, probably made heavy by the presence of an excess of 

 carbon dioxide over fire damp. 



Bowk. An iron bucket used for raising rock, etc., Avhile sinking. 



Brace. A permanent platform on the head frame of a shaft on 

 which men work. 



Brakesman. The man in charge of a brake which controls a gravity 

 plane. 



Branch rope. See District rope. 



Brasses A coal miner' term for iron pyrites in coal. 



Brassy tops. The top part of the Greta seam, in which there are 

 large quantities of sulphide of iron. 



Brattice. A vertical division of boards or cloth to separate tin* 

 intake from the return air currents. 



Brattice trick. A trick played on inspectors when measuring the 

 air in a mine, the quantity of air being reduced in some districts below 

 its normal amount, in order to increase it in the district being tested. 

 Usually effected by placing a piece of brattice cloth across one of the 

 return airways. 



Breathing apparatus. Apparatus connected with a mouth-piece or 

 helmet, which enables the wearer to penetrate places full of foul gases. 



Breeze. Fine coke. 



Bridge rails. Rails made in the form of an inverted IT, generally 

 in short lengths, which are light to handle, and can be brought within 

 easy shovelling distance of the face. 



Bridle chain. Short chains between the cage and the hoisting rope. 



Broken- Working in the broken is the process of removing the 

 pi liars in bord and pillar work, 



Broken skip. A skip from which some of the coal has fallen off in 

 transit. 



Broirn coal. A structureless variety of lignite. 



Brush. To brush the roof is to take down some of the rock over- 

 head to make head room. 



Buffer rope. Ropes placed between the track of cages in a shaft 



