405 



laying a double tramway (and a triple one for a short distance) 

 in the upper level ; and also of dividing the lower level into 

 three roads and two roads, instead of one. The plan, of 

 course, might be modified, but I contend for the principle as 

 being the best and only safe one, and it is equally applicable 

 in long-work as in panel-work. And if the upper level, con- 

 taining the returning currents, be divided as in the plate, an 

 additional security would be obtained, and any accident could 

 not possibly involve the whole mine. 



It is certain that if, at the Oaks Pit, near Barnsley, where 

 73 persons were destroyed a few days ago, there had been 

 a separate air course from the downcast pit to the workings 

 south of the throw, a great many lives might have been saved. 

 At the Has well Colliery, in the explosion, (Sept. 28, 1844,) 

 where 95 persons were killed, it is said that if the panel of the 

 Brockley- Whins-working had been a separate air course from 

 the downcast pit, 30 persons at least would have been saved, 

 and who were not very near the place where the mine exploded. 



It is maintained by some that by beginning at the far end, 

 as it is called, and working backwards, or in the direction of 

 the dip of the coal, the fire-damp is left behind in the waste 

 or goaf ; whereas if the workings be pursued from the levels 

 of the pit towards the rise, the gas follows the workmen up 

 the goaf, and becomes, towards the finishing of the workings, 

 a dangerous magazine of explosive mixture. 



It does not, however, seem capable of proof, that after the 

 coal has been worked out, there can be any difference in the 

 state of the goaf, z. e, whether the coal has been worked from 

 dip to rise, or from rise to dip. The roof will fall in to the 

 same amount, and in the same form and shape in both ways ; 

 and when the excavations are completed, will rise to the 

 highest portions of the goaf. 



The accidents in the Barnsley or Thick Coal have arisen 

 chiefly from using single board-gates, when the circumstances 



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