28 Messrs* Faraday a7id Lyell on 



blowing down of the stoppings, by destroying the ventilation 

 of the mine, caused all this choke-damp to be left for a time 

 in the workings; and there is reason to believe, from the cir- 

 cumstances, that the men met with a death comparatively 

 sudden. 



With such views of the character and effect of the goaf as 

 we have ventured to express, and with a strong belief that it 

 has been the cause of the recent sad event at Haswell, it will 

 not be thought surprising, that, in thinking of the means of 

 preventing such calamity in future, we should turn our atten- 

 tion almost exclusively to it. The first idea is to ventilate the 

 goaf. If a shaft could be sunk over the crown of the goaf, it 

 might perhaps carry away all the fire-damp; but the proba- 

 bility is that where furnaces are used in the upcast shaft, that 

 over the goaf would become a downcast shaft, so that all the 

 fire-damp evolved into it would have to pass into the mine and 

 out with the ordinary ventilation. Besides that shafts of such 

 magnitude are very expensive, the bottom part would be liable 

 to fall in ; the crown of the goaf vault, also, is in many cases 

 probably changing its place continually, and in inclined strata 

 it might easily happen in the course of working that the bot- 

 tom edge of the shaft would soon be below the upper edge of 

 the goaf basin in the mine, when it would be of comparatively 

 little use. These are difficulties and objections which occur 

 to us even in our theoretical considerations : whether practi- 

 cal men would set them aside, or whether they would add to 

 their number, we cannot say. 



Another mode of action has occurred to us, which, the more 

 we think of it, seems the more practical, and offers greater hopes 

 of service to humanity, and which, therefore, we shall venture 

 somewhat minutely to explain. It is founded on the principle 

 of drawing away the atmosphere in the goaf, not of ventilating 

 it by blowing air into it ; it is better in principle than blowing 

 into the goaf, because it proposes to take away the fire-damp 

 in a concentrated form, and never to give it to the air of the 

 workings ; whereas blowing would first dilute and expand the 

 gas, and then throw it into the works. The difference is 

 especially important for mines where the gas is abundant; for 

 suppose for a moment a goaf cavity full of fire-damp, and an 

 apparatus that could either blow into it or take from it an 

 equal quantity in each case, of air or gas ; to take out one 

 cubic foot of fire-damp would be to prevent the formation of 

 from 6 to 15 feet of explosive mixture; to drive in one cubic 

 foot of air would be to send an equal quantity of fire-damp by 

 displacement into the mine, there to form, at one moment or 



