1813.] 



Accident at Fellmg Colliery, 



357 



boards on the north are termed the narrow hoards : they were the 

 parts first excavated, and were made for the purpose of opening 

 a communication for the atmospheric air between the two pits : 

 the lines between the west end of the narrow boards and the 

 William Pit, are called drifts. The inclined plane board is 

 marked P P on the plan. 



The parallelograms formed by the boards and walls, are called 

 pillars : they are solid masses of coal left to support the roof of 

 the mine, and are each 26 yards long, and eight yards broad. 



The single black lines in the walls and stentings represent 

 stoppings, and the double lines trap-doors, each of which are 

 placed to divert the current of atmospheric air through proper 

 channels. The stoppings are made of brick and lime; and in 

 this colliery, were strengthened on each side with a v/all of 

 stone. The trap-doors are made of wood : each of them is 

 attended by a boy about seven, eight, or ten years old; and 

 they are seldom used but in the avenues leading from the work- 

 ing shaft to the workings. At the circle N, the air crossed the 

 waggon-way, and at M, the way to the stable, over arches of 

 brick. The walls which have stoppings in them, are called 

 sheth-ivalls, and those that are open, loose-ivalls. 



In all large collieries the air is accelerated through the work- 

 ings, by placing a large fire, sometimes at the bottom, and 

 sometimes at the top of the up-cast shaft, which in these cases 

 is covered over and connected with a furnace tube or chimney, 

 by an arched gallery of brick from 40 to 60 feet in length. In 

 this colliery the furnace was about six feet from the bottom of 

 the tube. 



The first course of the air, after descending the John Pit, was 

 tinder the arch M, up the inner narrow board and the stable 

 board S, to the trap-door at the head of the narrow boards ; 

 then down the board next south of the stable board; and so 

 afterwards up two boards and down other two, till it traversed 

 the newly formed shetfi or set of workings, branching from the 

 southernmost part of the double-headways on the east : from 

 thence it passed over the two arches up the outer board of the 

 narrow boards, to the most westernly sheth of boards, and after 

 fanning them, found its way down the crane board, along the 

 drift to the William Pit, through which it ascended into the 

 furnace, and thence, charged with noxious vapours, into the 

 open air. 



From this explanation it will easily be perceived that the purity 

 and wholesoraeness of a coal-mine has no reference to its depth. 

 If the air be conducted through all parts of a mine, as here 

 described, and no falls from the roof occur to prevent its visiting 

 every corner, the old excavations, which are called wastes, will 

 foe constantly ventilated by as pure air as the boards in which th^ 



