53 



mountain valleys j* nor do I conceive a resemblance, be- 

 tween the skirts of mountains, in distant countries, (even 

 if better established,) to be a fact of such importance, as 

 to warrant a general conclusion of their similarity, in all 

 other respects. 



It is amusing to observe, with what force 'Ms. Desmarest 

 puts this argument; how well satisfied he is with the vis 

 consequentice, and to what an extent he avails himself of it. 

 He says, " je tirai de cette conformite reconnue, une con- 

 " sequence, que la force de I'analogie m' autorisoit a tirer. 

 " Cette consequence me fit voir dans la Chaussee de Geans, 

 "■ et dans toutes les masses prismatiques, qui se montrent 

 " sur les hordes escarpees de la mer, en Irlande, en un mot, 

 " dans lies sommets tronquees, q'on y appercoit, Touvrage 

 " des eruptions, d'un ou des plusieurs volcans, qui se sont 

 " eteints, comme ceux d'Auvergne." 



I must make two observations on this passage. The first, 

 that Mr. "Desmarest calls this fanciful resemblance (he thinks 

 he has discovered) une conformiti reconnue, as if known and 

 admitte'd by all the world. 



The second, that he takes this opportunity of sliding in 

 a most important fact, sommets tronqueSs, truncated sum- 

 mits or cones, being one of the most characteristic features 

 of volcanic countries; of course, when found in Antrim, 



H decisive 



* Since I wrote the above, I have carefully examined Mrs. Drury's draw- 

 ings, which represent our uniform facades with great accuracy. No valleys 

 or ravines, either in nature or the drawing, nor any thing like the skirts of a 

 iwotmtain, 



