ON EXTINCT VOLCANOES. j 3^ 



I was told, that the outlet I have juft mentioned was arti- Theprefentout- 

 Ucial, and made fifty years after the building of the abbey. *" ^^ificial. 

 The foundations of this abbey, having .been funk as deep the natural one 

 as the outer w^alls are high above ground, had obftruaed the ^r^afdr'thc*^ 

 natural outlet, which occafioned the water to rife fo high, foundations of 

 as to inundate the convent, and render it neceflary to form ^^^ *^^^y' 

 the prefent channel, in order that it niightrun off. 



The face of the ground, however, makes me doubt. This queftloijr 

 whether the lake ever flowed over on the fide next the^ ^* 

 abbey ; for to a cOnfiderable diftance it rifes there uniform- 

 ly as you proceed from the fliore. It appeared to me, that as its natural 

 the natural outlet muft have been rather on the fide toward probably toward 

 Andernach, through fifllires on the mountain. Neither can Andernach, 

 I believe, that this lake, if we may judge from its banks, in dufmountafri 

 was the crater of a volcano; but one of the great excava- Neither was it a 

 tions produced by fome earthquakes. In facl, I have al- ^^^J,"' rodl«r 

 ready faid, that the eaft and north-eaft parts of this lake by an earth- 

 were volcanic : if therefore we fuppofe, that the fummit l^^ke. 

 of the mountain had been a volcano, its bafe mull necefla- 

 rily have become hollow^ and in this Hate of things, a very 

 flight fliock would have fufficed to break the arch of the 

 vault, or the crufl that covered its abyffes. 



We need not wonder, that this lake is always full of Receives water . 

 water, though it appears to recdve none in any part ; fince ^ounJin ^'^^ . 

 it ferves as a drain to the furrounding mountains, which tains. 

 are in great meafu re volcanic. Its wate^ is very limpid. Very clear, and 

 and it does not freeze except in very fevere frofls. -Mar- J^^" g"' ^^^'^^ 

 quart, in his origin of the Palatinate, aflerts, that it was p j. gjj jg 

 once larger than it is now ; which in fadt is perceptible on than it is now, 

 the fouth and wefl, where the ground has the appearance 

 of having been once covered witli water. He addsv that Sapphires and 



~ 1 /• 1 • r ' J • ' . 1 Other precious 



precious ftones and (apphires were found on its borders. I ftones, once 

 did nor fee any; but it is known^ that there is a fad of ^°""^ "'^ ''^^ 

 this kind in the little rivulet of Pezzouliou, that runs among a fimilir oc- 

 lava at Expilly, near Puy, in Velay. currence ac 



By no means fatisfied with my refearches, the principal ,*^* ^* 

 obje6l of which was, to difcover the crater of the volcano, 

 that could have produced all the la'*a in this country, I re- 

 paired to Medermenich, half a league to the fouth-eaft. 

 There I found myfelf in quarries of volcanic ftone. from 4^•^^*^^'■'"5' 



1-1 1 .,1 ^ 11 /. /. nick, quarries 



^vhich were taken mill-fteues and hewn-ftones for building, of voicar 



M 



inio 



ftones. 



