354: 



ALUM MINES OF AUBIN. 



The works 

 that have 

 been relin- 

 quish etl take 

 fire spontane- 

 ously. 



Four of these 

 only deserve 

 notice. 



river Lot, which runs near the mines. But this uniott of 

 natural advantages, far from being turned to profit by good 

 management, has hitherto given rise to various abuses ; 

 though I shall only point out that, which relates to the sub- 

 ject of the present paper. From time immemorial every 

 landholder has been at liberty to dig in his own ground, get 

 out the coal without order or method, and dispose of it as 

 he could. Hence the number of pits opened has had no 

 reference to the demand, and frequently individuals have 

 been obliged to relinquish their works for want of a sale 

 for their produce. Now from causes which it is useless to 

 discuss here*, the works. that are thus given up ^re liable 

 to take fire spontaneously, even when carefully watched. 

 The fire communicates very rapidly every where ; and if the 

 greatest exertion be not made to stop it in the beginning, it 

 becomes afterward impossible to check its ravages, and the 

 work is destroyed. It appears, that this misfortune hap- 

 pened very often formerly; for, on going over the surface 

 of the ground occupied by the mines, at almost every step 

 we meet with very evident traces of subterraneous fires 

 now extinct. Accidents of this kind are now more rare, either 

 from the people having learned how to prevent them, or 

 knowing how to check them : yet seven or eight works are 

 still burning at this moment. 



Among these works that have caught fire, those called 

 Lassalle, Fontaines, Bu^gne, and Bourlhones, are the 

 only ones remarkable, either on account of the intensity of 

 the fire and the space it occupies, the disruption andtorre- 

 faction of the earth as far as the surface, or the daily pro- 



the coal. 



* In general only the purest efeal is got out of the works. That 

 which is mixed with schist, being of no value, it is used with other 

 Spontaneous matters to fill up the vacuities made. Now whether this be fre- 

 combustion of quently accompanied with iron pyrites disseminated in it, or per- 

 haps even contain sulphur in combination, the fact is, that 

 moisture renders it a very active pyrophorus, in all parts of the 

 mines where the circulation of the air is stopped. The miners of 

 the country have but one opinion on the subject: they all agree, 

 that the spontaneous inflammation of the works is owing to the 

 action of stagnant water on the refuse left in them ; and that the 

 fire manifests itself the more speedily, in proportion as the circula- 

 lation of the air is more slow. 



dttctioa 



