118 THE CHEMISTRY OF COLLIERY EXPLOSIONS 



There are other phenomena that throw light upon the 

 velocity of the gaseous movement in the interval from explo- 

 sion to explosion. It has been already mentioned that in places 

 there was inadequate velocity to move the wagons along the 

 rails, disturb the pipes, carry a^vay the food bag, or the men's 

 clothes. About 300 yards from the shot or point of origin, 

 and in the interval between No. 5 and No. 6 explosions, 

 there were some wagons of coal standing upon the rails in 

 a siding in the path of the coal-dust. The wagons had one 

 open end in which the lumps of coal were built as a wall. 

 The coal in the end of the hindmost wagon was exposed to 

 the gaseous movement initiated by No. 5 explosion, and about 

 60 lbs. in lumps from 4 oz. to about 4 lbs., were missing, 

 and no trace of it could be found in the siding. Two 

 timber beams, each 6 feet long, Ij^ing against the roof, over 

 this and the adjoining wagon, were coated with a friable 

 deposit of coked coal throughout their length and upon 

 their opposing faces ; and amorphous carbon was in pro- 

 fuse distribution upon the vertical timber and side walls. 

 At the Timsbury Collieries a wagon of coal was resting 

 on the rails about 70 yards beyond the sixth explosion, 

 with blocks of coal raised above the wood-work. The faces 

 of this coal had burst out into globules of bituminous 

 matter, which had undergone further destructive distillation, 

 leaving residues of comminuted coke. Globules still re- 

 mained attached to the faces of the coal in different stages 

 of formation ; and the ledges of the coal, the edges of the 

 wood sides and ends of the wagon, and the buffers, were 

 loaded with accumulations of coke the size of small shot, 

 which had gravitated downwards from one resting-place to 

 another. The reduction of blocks of coal by heat, in the 

 conditions prevailing in a colliery explosion was exhibited 

 at this wagon, and confirmed the supposition that the coal 



