8 inches of coal is a thin bed of sagger, then 10 inches of bottom coal, followed by 8 inches of sagger, then 18 inches of coal, all of which are taken out in the main roads to make height, but the coals are inferior and unmarketable, and so are left on in the ordinary working. Below come 3 feet of blue metal, and then 3 or 4 fathoms of sandstone. The workings of the Silksworth pit are within half-amile of those at Wearmouth, and although the Maudlin Seam is not quite so thick at Silksworth, the coal is very similar at both places. The main roads are timbered as at Wearmouth.

Fig. 220 shows the usual method of working the pillars at Silksworth. First the 50-yard square pillar is split by means of an 8-foot place. From this split, and also from the ending parallel to it, lifts are taken out. These lifts are 6 yards

In the two

wide, and each is carried 20 yards to the rise and 5 yards to the dip. lifts being driven at the low side of the pillar in Fig. 220, it is seen that the portion of 5 yards to the dip, belonging to those lifts, is not taken out. That operation would follow the completion of the rise portion of the lift. The lifts are kept stepped."

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Fig. 221 shows the practice of working the pillars at Silksworth, where the roof is good. Here the lifts are driven half-way up the pillar from both sides without splitting it. The place is commenced 6 feet wide, leaving 4 yards of solid coal between the road and the goaf, and is continued this width for a distance of 4 yards, after reaching which it is widened out to the waste. This leaves a "stook" or small pillar, of 4 yards square, between the road and the goaf. The lift is carried half-way across the pillar, or 25 yards, after which the props are drawn by the deputy, and the roof allowed to fall. Two men work in each lift in each shift, there being a fore and back shift. They are paid 8d. a ton for hewing and filling the coal. As a fact, the lifts are taken off the pillars on both sides of the split, as shown in Fig. 220, but Fig. 222 shows how they might be arranged to be worked from one side only. The workmen "scallop the coal, there being no holing, and therefore no spragging. Props and "sets,' the same as at Wearmouth, are used, the sets being arranged with the rails between them in the lifts, and placed about 18 inches apart. On the waste side of the road three rows of 6-inch props are placed about a yard apart, as shown in Figs. 220 and 221. There is no rule in force as to the distances apart these props are to be placed, but there is an understanding that they are not to be more than a yard. The deputy sets them, and when the lift is finished he draws the props out, commencing at the inside. The hewers are out of the pit when the deputies draw props. The 4-yard "stook" is then worked off and the props drawn. In cases where the deputies cannot draw the whole of the timber without assistance, timber drawers, who are always spare deputies, are put on to help them. These men receive 8d. and 10d. a score for taking out the props, but this price is paid only on whole timber, unless the broken timber is required, in which case two broken props count as one whole one. A deputy attends to 10 or 12 men, his duty being to set and draw timber for the men, and see that all the ventilating arrangements are right. He works an 8-hour shift, the same as the colliers, and during his shift visits each place twice. He receives a daily wage.

The whole-mine workings are the same as at Wearmouth. the coal is good, the cost of timber being 24d. per ton.

The roof over

At the Florence Colliery, Longton, North Staffordshire, the Great Row Seam is worked by the Longwall method. At this Colliery, which is quite new, two shafts prove the Great Row Seam at a depth of 352 yards. The pits are 12 and 14 feet in diameter, one being the downcast, the other the upcast. The downcast was sunk 746 yards to the Moss Coal, which is the best household coal of the series, and the sinking of the upcast to the same seam was proceeding in 1881.

The downcast is used to wind coal, for which purpose a pair of high-pressure

Fig. 222.-SILKSWORTH COLLIERY, NEAR SUNDERLAND, SOUTH DURHAM. PLAN SHOWING A POSSIBLE ARRANGEMENT OF PILLAR WORKING FROM ONE SIDE OF THE SPLITS, IN THE MAUDLIN SEAM.

horizontal winding engines, with 42-inch cylinders, 7-foot stroke, double beat valves, and a 28-foot diameter cylindrical drum, are used. The engine is supplied with an automatic cut-off, to stop the cage when it reaches the surface. Coals are placed in the cages at levels or loading stages in the shaft, besides the bottom; these levels being at the Bassey, Chalky and Ash Seams, which are all worked above the Great Row.

In 1881 a Waddle fan, 45 feet diameter, was being erected at the upcast shaft.

Fig. 223 shows a section of the Great Row Seam, the average thickness of which at this colliery is, however, 6 feet. Over the coal are 8 feet of fireclay, and above this a bed of coal 2 feet 6 inches thick. Resting on this coal are beds of fireclay and bass (hard dark shale), 8 feet thick. Above this again come 8 feet of coal and partings, and then higher, 32 feet of "Binds, Slums, and Marls." The thill is composed of 37 feet of "Bass, Binds, and Clod."

The seam dips 1 in 7. Fig. 224 is a plan showing the method of working. From the pit bottom, for a distance of 350 yards, a pair of levels 10 yards apart were driven, and, on reaching a certain point, a breasting" or face of coal 25

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MODE OF PROPPING AND

Fig. 223.-FLORENCE COLLIERY, LONGTON, NORTH STAFFORDshire,
SPRAGGING AT THE WORKING FACE ON THE GREAT Row SEAM.

yards wide was taken out, and a "gob" road formed in it 4 yards from the deep side-rib. The stall-roads are turned out of this gob road every 88 yards, and carried to the rise. They are cut off by a level every 120 yards. The faces are "stepped," one being 15 or 20 yards in advance of another. The coal is conveyed along the main level by horses, but a "jig," or self-acting incline works in every going stall-road, by means of which the coal is let down to the level.

For this purpose a 12-inch wheel is placed in a fork, and the end of the fork is passed through a prop at the road-head. A brake, consisting of a piece of iron, is pressed on the rim of the wheel by a handle working a dumb screw fastened to the fork. Only one tram is run at a time; each tram holds 8 cwts., and the brake is just powerful enough to stop it at any point during the run. A chain is used on the inclines, and as the face advances the wheel is easily moved forward.

The bottom level advances, taking a "breasting" or face of 25 yards. The road is 6 feet wide, and on either side of it a pack-wall, 3 yards wide, is built. The face is protected by two rows of props, which are 6 inches in diameter, the rows being placed 4 feet 6 inches apart, with a 5 or 6-foot space between the props. The lids used over the props consist of broken props, when there are sufficient for that purpose. Fresh building is put in every 5 feet, the rear row of props being drawn and re-set in advance. Sprags 6 feet apart are used under the coal. The space between the pack-wall and the coal on the deep-side is kept open as long as possible, but when this can only be done with difficulty, a hole is driven through the building from the road, and a fresh air-course carried on from this point. A chock of broken timber is fixed at the corner of each hole, and there is an interval of about 40 yards between these holes.

The stalls are 88 yards wide, and packs 3 yards wide are built parallel to the road (which is wide enough to admit of a double road for the self-acting inclines) 7 yards apart all the way from one stall-road to another.

This will be seen in Fig. 225, which is an enlarged plan showing the packs, timbering, &c. The packs formed next the roads, it will be observed, are wider than those in the waste, being 4 yards. The stones obtained from the 3 feet of ripping are used to build the packs on both sides of the roads. In every 88-yard stall, are two stall-men, one for each side of the road. In their employ are 4 holers, 2 buttockers, and 2 packers.

The stall-men build the packs, set and draw the timber, and despatch the coals down the incline to the level, for which they receive 15s. per score of tubs of coal-7s. being allowed for slack-all of it being raised. The workmen rake the coal into iron boxes or trays 2 feet square and 6 inches deep at the one end,

Fig. 225.-FLORENCE COLLIERY, LONGTON, NORTH STAFFORDSHIRE. PLAN OF LONGWALL FACE
WITH THE GATE-ROAD AND PACKWALLS CONNECTED WITH IT, IN THE GREAT ROW COAL.

tapering out at the other. For carrying, these have two handles, which also enable the workman to empty the coal into the tubs conveniently. The men in one of these stalls send out during the day, or shift, 100 tubs, each of which holds 8 cwt. Besides the score price referred to, the stall-man receives 5s. 6d. a yard, for top ripping and building the road packs. Any other stones required for packs are obtained from the waste. The holing under the coal is made 4 feet in, being 2 feet high in front, the holer placing sprags under the coal every 6 feet, as shown in Fig. 223. The sprags are 2 feet long and 6 inches in diameter. The holing across the stall being finished, the sprags are knocked out; the coal is then blown down by powder. The stall-man fires the necessary shots. The coal is shot down in advance of the point where the rails are laid, but for the convenience of filling, the rails are kept very close up to the "buttock" or piece of coal, next to be blown down, and advanced as required. The holers are not obliged to remove from one side of the stall to the other, as the shots are fired, but only those working on the side where the firing takes place. After the shot is fired, they return to their work and continue as before. The props at the face are in two rows, 4 feet 6 inches apart, there being 6 feet between the props forming a row. They are from 5 to 6 inches in diameter at the thin end, and are put in by

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