MINING FOR COAL 



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quent falls of coal, they plant props of wood for their protection at regular distances 

 in an oblique direction between the pavement and wall face, called spragging. Indeed, 

 as a further precaution, staples of coal, about 10 inches square, are left at every 6 or 8 

 yards, till the line of holing or curving is completed. The walls are then marked off 

 into spaces of from 6 to 8 yards in length ; and at each space a shearing or vertical 

 cut is made, as deep as the holing ; and when this is done, the holer's work is finished. 

 The set who succeed the holers are called getters. These commence their operations 

 at the centre of the wall divisions, and drive out the gibbs, or sprags, and staples. 

 They next set wedges along the roof, and bring down progressively each division of 

 coal ; or, if the roof be hard-bound, the coal is blown down with gunpowder. When 

 the roof has a good parting, the coals will frequently fall down the moment the gibbs 

 are struck ; which makes the work very easy. The getters are relieved in their turn 

 by the third set, named butty-men, who break down the coals into pieces of a proper 

 size for sending up the shaft, and take charge of turning out the coal from the wall 

 face to the ends of the roads. This being done, they build up the stone pillars, fill up 

 the gobb, set the trees, or props, clear the wall faces of all obstructions, set the gibbs, 

 and make everything clear and open for the holers to resume their work. If the roads 

 are to be heightened by taking down the roof, or removing the pavement, these butty- 

 men do this work also, building forwards the sides of the roads, and securing them 

 with the requisite props. When a coal has a following or roof stone, which regularly 

 separates with the coal, this facilitates the labour, and saves much of the coal ; and 

 should a soft bed of fire-clay occur a foot or two beneath the coal-seam, the holing is 

 made in it, instead of into the coal, and the stone betwixt the holing and the coal 

 benched down, which serves for pillars and gobbing. 

 In this way all the vendible coal becomes available. 



Another form of the Shropshire system is, for each 

 miner to have from 6 to 12 feet of coal before him, 

 with a leading-hand man ; and for the several work- 

 men to follow in succession like the steps of a stair. 

 When the coal has open backs and cutters this work 

 goes on very regularly, as represented in fig. 1513, 

 where the leading miner is at a, next to the outcrop, 

 and b b, &c. are the wall faces of each workman ; A 

 being the shaft, and B the dip-head level. In this 

 case the roads are earned either progressively 



through the gobb, or the gobb is entirely shut up ; and the whole of the coals are brought 

 down the wall-faces, either to the dip-head level or the road c c. This method may 

 be varied by making the walls broad enough to hold two, three, or four men, when 

 each set of miners performs the whole work of holing, getting, breaking down, and 

 carrying off the coals. 



It is estimated that from one-eighth to one-twelfth part only of the coals remains 

 underground by the long-wall plan ; nay, in favourable circumstances, almost every 

 inch of coal may be taken out, as its principle is to leave no solid pillars nor any coal 

 below, except what may be indispensable for securing the gobb. Indeed, this system 

 might be applied to coal-seams of almost any ordinary thickness, providing stuff to fill 

 up the gobb could be conveniently procured. 



When coals do not exceed 20 feet in thickness, and have good roofs, they are some- 

 times worked as one bed of coal ; but if the coal be tender or free, it is worked as two 

 beds. One-half of sxich thick coal, however, is in general lost in pillars ; and it is 

 very seldom that less than one-third can be left. When the coal is free and ready 

 to crumble by the incumbent pressure, as well as by the action of the air, the upper 

 portion of the coal is first worked, then a scaffolding of coal is left, 2 or 3 feet thick, 

 according to the compactness of the coal ; and the lower part of the coal is now worked, 

 as shown in fig. 1514. As soon as the workings are completed to the proposed extent, 

 the coal scaffoldings are worked away, and as much of the pillars as can be removed 

 with safety. As propwood is of no use in coal-seams of such a 

 height, and as falls from the roof would frequently prove fatal to 

 the miners, it is customary with tender roofs to leave a ceiling of 

 coal from 2 to 3 feet thick. This makes an excellent roof; and 

 should it break, gives warning beforehand, by a peculiar crack- 

 ling noise, very different from that of roof-stone crushing down. 



One of the thickest coals in Great Britain, worked as one bed from roof to pave- 

 ment, is the very remarkable seam near the town of Dudley, known by the name of 

 the Ten-yard coal, about 7 miles long and 4 broad. No similar coal has been found 

 in the island; and the mode of working it is quite peculiar, being a species of panel 

 work, totally different from the modern Newcastle system. A compartment, or panel, 

 formed in working the coal, is called a side of work ; and as the whole operation is ex- 



1514 



