CAUSES OF EXPLOSIONS IN MINES. 687 



41 Davy and Clauny lamp at a greater velocity than 7 feet per second, or if 

 the lamp is traversed by a sound-wave; (3) if a blasting shot is fired di- 

 rectlj" into it; and lastly, if it reaches a safety-lamp that has been opened 

 by one of the men. 



The means that have been provided for guarding against these contin- 

 gencies are as follows: — (1) Furnaces have to a large extent been re- 

 l^laced by ventilating fans in fiery collieries. (2) Davy and Clanny lamps 

 are still almost universally employed. (3) Shot-firing, having been found 

 to originate many explosions, although probably in a manner not j^et 

 understood by most people, is now carried on under certain restrictions 

 which are still insufficient. (4) Much nonsense has been talked and writ- 

 ten about miners opening their lamps. The present flimsy pretense 

 ■for a lock is not a necessity but a cheap convenience; and who is respousi- 

 "ble, if, say 100 men are killed through its being opened by one? Is there 

 no responsibility attached to the owners or the legislature for placing the 

 lives of ninety-nine innocent men in danger? I think there is. The in- 

 fluence of changes of weather on the internal condition of mines has been 

 remarked since the remotest times, and for the last fifty or sixty years at 

 least many have asserted that firedamp is more prevalent when the barome- 

 ter is low than in the opposite case. When vigorous artificial means of ven- 

 tilation are employed, and ordinary skill practiced in distributing the air 

 the effects of change of weather become much less perceptible. If a large 

 proj)ortion of explosions can be shown to occur simultaneously with, and 

 therefore, presumably, in consequence of, those atmospheric changes that 

 would tend augment the amount of firedamp in the workings, there is a 

 strong argument in favor of the supposition that they are preventible, and 

 cannot therefore be considered as accidents in the true sense of the term. 

 With this object in view, diagrams have been made from time to time by 

 Mr. E. H. Scott and myself, and also by one or two others, showing the con- 

 nection that exists between the two classes of phenomena, and an examin- 

 ation of these is sufficient to convince unbiased persons that there is a stri- 

 king coincidence between the explosions and the favorable atmosj)herical 

 conditions. A general rule was inserted in the Coal Miners' Eegulation 

 Act (1872) making it'compulsory tor mine-owners to place a barometer and 

 thermometer at the entrance of every mine in the coal measures. It has 

 always been difficult, and sometimes impossible, for mining men to give an 

 adequate reason for the extent of great explosions; and more especially 

 when it is known that, immediately beforehand, little or no inflammable 

 gas has been present in the workings. The reports of the Inspectors of 

 mines bear ample testimony to the correctness of this statement. In Sep. 

 tember, 1844, before the appointment of inspectors of mines, Lyell and Fara- 

 day were sent to Haswell Colliery by the Home Secretary to report on an 

 explosion that had just taken place there. I am unable to quote from their 

 official report, but I am firmly convinced that the following sentences taken 

 from their article on the subject in the Philosophical Magazine, 1845, is the 



