uTid Spouting Fountains. 245 



From the 14th to the 18th (5 days) there was a fall of 145 ft. 



On the 19th a rise began. 



From the 19th to I6ih November, the rise equalled 116 feet. 



From 14th November to 16th there was a fall of 15 feet. 



On the l6th a rise again began. 



From the 16th to December 15th, there was a rise of 34 feet. 



These oscillations, assuredly most extraordinary, as much from 

 their irregularity as their extent, would require to be observed 

 -for a much longer period before any explanation could be offered 

 .with any prospect of success. 



Are these Wells likely to become exhausted 9 



This is a question that is very often put. As an answer, we 

 shall mention two facts which are well calculated to dispel all 

 fears on the subject. 



The fountain of LillerSy in the department of Pas-de-Calais, 

 the sinking of which extends as far back as 1126, has uniformly 

 projected its waters to the same height above the surface, nor 

 has the quantity which it furnishes in twenty-four hours ever 

 varied. 



The well of the monastery of Saint Andre, appears now to 

 be, so far as it regards the height of its jet, and the quantity of 

 water which issues from its upper orifice, in precisely the condi- 

 tion in which it was when Beiidor observed it more than a cen- 

 tury ago. 



Of Wells vJience gas issues. 



In searching for water in the bowels of the earth, sometimes, 

 instead of this liquid, great reservoirs of some gas are discovered, 

 which immediately rises to the surface. This gas is usually in- 

 flammable ; sometimes it is pure hydrogen, but more frequently 

 carburetted hydrogen, — that gas which so frequently collects in 

 coal-pits, and gives rise to such dreadful explosions, or, in other 

 terms, that gas which is now so much employed for domestic 

 purposes. 



The Chinese have many wells of this description. The gas 

 which was disengaged from that which the Abb^ Imbert visited 

 a few years ago, was conducted by long pipes, under more than 

 three hundred gasometers, whence it was transmitted to be 



