1814.] On the Ventilation of Coal-Nines. 199 



is, I should suppose, very probably generated at some one or more 

 places in ihe mine. H this is the case, what do currents oi' air 

 passing down one shaft and diverted by drifts and Irap-doors till 

 they find an exit at anotiier, do more than this; that they mix with 

 the gas, and carry it with them through all the circuit, dispersing 

 it, though diluted more or less, over a considesable space. 



On the other hand, a powerful exhausting engine may be brought 

 to act at once on any particular point; and by a system of pipes, 

 laid in a judicious manner, and provided with orifices which might 

 instantly he opened at one place and closed at others, the gas might 

 be pumped out from its source without mixing with the air of the 

 mine, while the influx down the shafts would serve to keep the 

 whole atmosphere of the mine in such a state as wouW ensure 

 safety. 



The extent of exhausting power to effect this would be a matter 

 of no difiicult calculation fn- any cure, ai;d 1 have no doubt that 

 other good means of obt.iining it might be deviled, as well as those 

 I have practised. I sii.ill only say in their recommendation, that 

 they are simple, not expensive, not liable to frequent repair, and 

 having hut little friction may be worked by any first mover without 

 laying such a burden on it as could be important in any under- 

 taking of this sort. 



1 have, however, no particular reason for recommending this plan 

 of my own: the object tor uhich it was invented has been attained; 

 its use is free for any persons that may wish to try it ;~and I need 

 only say, that I shall cheerfully give every information about it, and 

 the improvements it has since received, to those who may desire it; 

 and so, 1 am couvuiced, would the agents of the Tavistock canal, 

 where it is still in daily use. 



One thing is clearly shown by the recent event at the Felling 

 colliery, situate in one of the great coal districts of England, which 

 is, that all the means they are at present acquainted with are 

 inadequate to secure them from danger. This colliery is described 

 as being exci llently managed, and its api)aratus and construction 

 upon the best known principles, and yet with the dreadful catas- 

 trophe before them which happened only eighteen months ago, and 

 witii the most laudable exertion on the part of the proprietors to do 

 all that could l)e thought of, another dreadful event has taken place, 

 carrying uiist-ry to the widows and children of the workmen, and 

 destroying the profu due to the enterprising spirit of the owner:;. 



I understood that when my paper was read at the Society of Arts, 

 it was said by a great coal owner that he despaired of any plan of 

 ventilating collieries, however plausible, because none had hitherto 

 succeeded, in the same manner, 1 was told by a friend, whose 

 experience in mining is as great as that of niost men, that 1 should 

 find it impu •^•ble to ventilate the Tavistock tunnel with less than 

 three times the number of shafts which 1 liavc since actually em- 

 ployed. 



The failure of old plans seems to mc rather a reason for cxpeii- 



