At the flat, near where the body of Winn the putter was found, three safety lamps were found. One, that used by Winn, was locked and undamaged, and when tested did not pass flame. The other two were spare lamps and were placed in a box hung at the side; this box had been blown down by the explosion, and the lamps thrown out and partly buried by a fall of stone. One of these lamps was damaged, the oil cistern was dented and the glass broken; when fitted with a new glass and tested it did not pass flame, the other spare lamp was not damaged and stood the test without passing flame. Both the spare lamps were locked.

There was nothing to suggest that any of the safety lamps had caused the explosion, the only one that was damaged had evidently been damaged by the explosion which had travelled to it.

We have no means of knowing what actually took place at the firing of the shots beyond the fact that the first shot had been fired without any explosion resulting. Whether any examination was made by Greenwell before the second shot was fired must remain an open question, but I may say that I have had evidence in some blasting accidents that it is not uncommon in the case of firing two or more shots in succession in a place, for the deputy or shot-firer to remain at the battery and leave it to the hewer to couple up the cable to the second shot.

We are also unable to determine what was the effect of the first shot; it may have blown the coal nearly right across the face, leaving little for the second shot to do, and as this shot was not stemmed with clay it was the more likely to produce flame. The bridge of coal already mentioned would confine gas within its area.

Westfalite cannot, on account of this explosion, be considered more liable than the other Permitted Explosives to ignite fire-damp, as the conditions under which the second shot was fired were probably so favourable for ignition of the fire-damp present that had any other of the Permitted Explosives been used the result would probably have been the same.

The air entering Suggett's stenton had already swept round Barnes' place and the middle headway, and would probably contain from one to two per cent. of fire-damp, and the air leaving it would contain a higher proportion.

The effect of the first shot would be to expose fresh surfaces of coal and increase the issue of gas at the face, of which there must have been a considerable proportion in the air.

A smart ignition of fire-damp and air would follow the explosion of the second shot, and appears to have been sufficiently vigorous to raise and inflame the coal dust in the passages over which the explosion extended, and this inflammation would be assisted by the percentage of fire-damp present in the air.

In the initial ignition of fire-damp by the flame of the shot the effect of dust cannot be altogether dismissed. The late Sir F. Abel conducted. some important experiments on the behaviour of dust in mixtures of fire-damp and air in connection with the inquiry into the explosion which occurred at Seaham Colliery, in the County of Durham, on the 8th September, 1880, and was struck by the fact that one sample of dust containing comparatively little inflammable matter had the effect of causing flame to spread through a mixture of fire-damp and air not inflammable per se; this led him to continue the experiment with absolutely non-inflammable dusts such as calcined magnesia, and he obtained similar results, and he stated the conclusions he arrived at as follows :—

In the present case there would be an explosive mixture of fire-damp and air at the face of Suggett's stenton, but further out-bye on both sides of the brattice the proportion of fire-damp in the air would be less, and may not have been capable of transmitting flame, had it not been for the effect of dust left suspended in the air from the first shot, and dust resulting from the explosion of the second shot acting simply as a finely-divided solid, and apart altogether from its inflammability, in extending the flame of the fire-damp to a distance to which it might not otherwise have penetrated.

There have been several cases in which explosions of fire-damp and air have occurred after the firing of a second shot, and it is possible that the dust floating in the air due to the firing of the first shot may have been a predisposing cause in the manner suggested by the late Sir F. Abel.

I do not think that Greenwell would have fired the second shot had gas been showing on his lamp where the battery was placed and where he must have observed it. I do not think that the air current would contain sufficient firedamp to transmit flame in the absence of dust and so carry forward the explosion, and this is proved by the fact of the three headways not being affected at the face although the air current extended into all of them.

It might be contended that a layer of gas existed next the roof which had escaped notice ; this would be so at the face of Suggett's stenton, but it is difficult to conceive such a condition holding over the whole area affected, and, if it was so, why did the faces of the three headways escape ?

Probably had coal dust been absent there would have been a minor explosion of fire-damp and air at the face of Suggett's stenton which might or might not have burned Greenwell and Suggett.

It is even doubtful in such a case if any lives would have been lost, certainly Barnes and the putter would have escaped without difficulty.

It will be noticed that none of the persons within the area affected by flame and force had been under any alarm at the moment of the explosion; the putter was at the flat, where the driver, who was injured, had left him waiting till the hewers would have any tubs full. Barnes had been drilling a hole, and Greenwell and Suggett were in a place of safety awaiting the explosion of the shot.

Can we assume that over the area affected elements of explosion existed in the shape of fire-damp and air which had escaped their notice; it is almost impossible to do so, their lamps would have been affected and probably extinguished had such a condition existed.

It has often been assumed in connection with previous explosions that an explosion of fire-damp and air in a limited area had produced effects of burning and force far beyond such area. A little consideration should satisfy anyone of the impossibility of transmitting great force in the passages of a mine through the medium of an elastic body like air, and before burning effects could be produced at a distance from the inflammable agent, the intervening columns of air would require to be instantaneously displaced.

If Suggett's stenton had been filled with the most explosive mixture of fire-damp and air to its full capacity, it could not on ignition have produced the results observed.

The explosion was arrested in its course out-bye owing to the cessation of the supply of coal dust; this happened to be coincident with the wet zone, but was not altogether due to it, as the roads beyond, driven in the so-called Towneley seam were, as already stated, free from dust, but however this might be it was clear that the explosion had extended as far as the supply of coal dust existed, and was practically co-extensive with the deposits of coked coal dust.

There is an impression that it is only the fine dust on the upper surfaces of main haulage roads that is a source of much danger, but it must not be forgotten that dust of a similar character is also present at the working face and roads adjoining, but here it is practically confined to the floor and mixed with coarser particles and impurities, and is not so readily thrown into the air as a cloud, nor has the air the velocity to sustain, in such situations, a cloud as it has on main roads.

It may, however, probably be true that the purer particles of the coal dust at the working face are more readily inflammable than the older deposits on the upper surfaces of main roads, and the fact that it is so rarely inflamed may be due to its position.

It is by no means universal in dry seams for coal dust to exist on the floor at the working face, and in roads adjoining in quantity and purity sufficient to propagate an explosion; it is often so mixed with stone dust, on the putting roads at and near the working face where the bottom stone is ground up by the ponies' feet as to lose its specific character; in the case of thin seams where top stone is shot down or bottom stone shot up to make height within a yard or two of the face, the coal dust produced in working the coal is also much obscured, and there have been numerous examples of explosions on mechanical haulage roads dying out on dry roads before reaching the face.

The Busty seam is one of the seams where explosions have swept round the working faces. This was exemplified in the explosion at Pelton Colliery in Durham, where 24 lives were lost on 31st October, 1866, by the explosion at West Stanley Colliery in Durham, where 13 lives were lost on 19th April, 1882, and by the explosion at Walker Colliery in Northumberland (working the upper section of the seam under the name of the Brockwell seam) on 24th October, 1887, where eight lives were lost. Also on 30th May, 1826, an explosion occurred in the Five Quarter seam (which is the lower portion of the Busty seam) at Towneley Colliery in Durham, causing the loss of 38 lives, but I am not in a position to say what parts of the mine were affected in this case. The West Stanley and Walker explosions were both investigated by me, and in the reports of the Inspectors of Mines for the year 1866, a fairly full description of the Pelton Colliery explosion is given. In describing it at the inquest the late Mr. Wm. Armstrong said: "The seam is an exceedingly dry one, and there is much dusty small coal lying throughout the workings. The explosion would, from the heat generated, expand the air to a very considerable volume, and the air seeking relief at a very high velocity in every direction would catch up these small particles of coal, set fire to them, and drive them through the workings in a dense cloud . . . I never saw such a quantity of charred small coal cast about at any explosion."

The coal dust in the area affected by the explosion would be produced as follows :—

As the places were all narrow the effect of (b) and (c) would be greater than usual, and the operation (d) is somewhat exceptional.

The fact of the explosion not reaching the face of the three headways presents a difficulty in this connection ; if so much coal dust existed why was the face not reached by the explosion? Two reasons may be put forward :

Apart from these reasons the face of the right-hand headway may have escaped owing to the wet ground at its entrance.

I have the honour to be,

Sir,

Your obedient Servant,

J. B. ATKINSON.

The Right Honourable

The Secretary of State,

Home Department.