SALTER — A CHRISTMAS LECTURE ON COAL. 



67 



furnaces. There are one hundred and two mills and forges in the 

 Staffordshire district. For this information, also, I am indebted to 

 Mr. Robert Hunt, of the Mining Record Office. 



We are not talking, however, of Staffordshire, but of coal mining in 

 general, and now a word on the ventilation — the most important of 

 all things for a mine after the water has been expelled. 



Without a furnace to create an upward draught in the one shaft, 

 so that the air may rush down the other and travel through the mine, 

 the work would be well nigh impossible. The way this precious air 

 is made to circulate throughout, instead of merely going from one pit 

 to another, is partly explained by our diagram, fig. 5, p. 64. The arrows 

 point the way the air goes up one side of the workings, round the fur- 

 ther end, nlong the working faces of all the galleries, and then back 

 again nearly to the same point to the upcast shaft, JJ. There tha 

 contaminated air, after passing the mouth of the burning fiery furnace, 

 gains the upper world, and makes room for a better and purer element. 

 The air is restricted to this course by the air-doors, which are marked 

 as black lines in our plan, across the galleries. These are strongly 

 framed doors, of iron chiefly, and are kept by boys, " trappers," as 

 they are called, whose sole and solitary work it is to open and shut 

 these trap doors whenever a train of waggons passes. A few words 

 of converse with the " putter" lads, who bring the loaded skips down 

 the " ways" — or it may be, quite as likely, a scuffle with them — are 

 the only relief these poor boys have (they are mostly very young) 

 during the dark and solitary hours. They cannot afford a " low" or 

 candle for the " trapper" boys ! 



In most of the important mines, a separate "windway" or "airhead" 

 is driven by the side of the galleries (or an air-tight wooden tube 

 is carried along), exclusively devoted to air from the downcast shaft; 

 and then, after supplying the miners in the stalls, finds its way back 

 along the galleries, escaping every time an airdoor is opened. The 

 same method is adopted in longwall work. But occasionally, as I 

 learn from Mr. Smyth, they work two galleries side by side ; and use 

 one of these for the incoming air, and the other for the return draught. 

 Whichever mode is adopted, the principle is the same, viz. : to carry 

 the air all round the mine, drawing it forcibly down one shaft and up 

 another, at the other end of the system. Be it remembered the 

 actual heat of the earth is much greater below the surface than above; 

 that choke-damp (an elegant term for carbonic acid) and other 

 poisons too sometimes, are present in the mine ; and ventilation, 

 whether by fans or furnaces, will be seen to be vital to the work. 



Any neglect in this important matter exposes the miners not only 

 to the displeasure of the overseers, and the ill report of the govern- 

 ment inspector, but to the positive danger of explosion from the foul 

 gas, which is ever accumulating in the mine- The fearful fire-damp, 

 which has played so terrible a part of late, is generated rapidly in the 

 coal pit. It is carburetted hydrogen, the same gas which burns harm- 

 lessly in our streets. It rushes out from many a fissure and dark 

 chamber upon the miner, who, in spite of all the precautions taken for 



