VOL. XXVI.] PHILOSOPHICAL TRANSACTIONS. 451 



the candles. Sulphur differs in this, that as the other suffers not the candles to 

 burn, this makes them burn too fast ; and the flame, by the impulsive quality of 

 the air, or attracted by the sulphur, extends itself upwards into a prodigious 

 length, and, like a match lighted for the discharge of a cannon, as speedily sets 

 on fire that vapour, equally destructive as gunpowder. 



Now to prevent both these inconveniences, as the only remedy known here, 

 the viewer of the works takes the best care he can to preserve a free current 

 of air through all the works, and as the air goes down one pit, it should ascend 

 another. But it happened in this colliery, that there was a pit which stood in 

 an eddy, where the air had not always a free passage, and which in hot and 

 sultry weather was very much subject to sulphur ; and it being then the middle 

 of August, and some danger apprehended from the closeness and heat of the 

 season, the men were with the greatest care and caution withdrawn from their 

 work in that pit, and turned into another ; but an overman, some days after 

 this change, and upon some notion of his own, being induced, as is supposed, 

 by a fresh, cool, frosty breeze of wind, which blew that unlucky morning, and 

 which always clears the works of all sulphur, had gone too near this pit, and 

 had met the sulphur just as it was purging and dispersing itself, upon which 

 the sulphur immediately took fire by his candle, which proved the destruction of 

 himself and so many men, and caused the greatest fire ever known in these parts.* 



An Experiment for continuing several Atmospheres of Air, condensed in the space 

 of one, for a considerable Time, By Mr. Fr. Haukshee, F. R. S. N° 3 1 8, 

 p. 217. 



On March 20, 1708, I injected with my syringe, into a very thick flint-glass 

 bottle, between four and five atmospheres of air, as appeared by the included 

 gauge, and which continued in that state till about the 7th of August foUovr- 

 ing, when looking on it, as I commonly did once in four or five days, I found 

 that the injected air had made its escape, the weather for a week before having 

 been very hot ; especially one day I observed the spirit in the thermometer had 

 ascended 120 degrees above the freezing point. And notwithstanding the 

 bottle was continually kept under water, yet the cement, used to fasten the 

 brass cap to it, was so softened, as to render it unable to resist the spring of 

 the injected air. I observed, that though all the air that was capable of elas- 

 ticity was fled, yet the mercury in the gauge remained about three quarters of 

 an inch in height, above the surface of that in which its opened end was im- 



* What is here termed sulphur is inflammable air or hydrogen gas, called bjr miners fire-damp. 

 See note at p. \6, vol. i. of this Abridgment. 



3 M 2 



