124 Dr Boue on the Elevation ()f Mountain Chains^ 



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tions produced by elevation, would not be everywhere present, 

 a position which is just what M. de Beaumont admits. 



It is probably to Mr Lyell that M. de Beaumont alludes, as 

 considering " les dislocations de couches qui caracterisent les 

 pays de montagnes, comme les resultats de phenomenes locaux, 

 qui se seraient repetes d'une maniere successive et irreguliere."" 

 (p. 260.) Unfortunately M. de Beaumont has not always at- 

 tended enough to the mean directions (directions moyennes) of 

 the various mountain ranges; and, on the other hand, leaving 

 these natural guides to the labyrinth of dislocations, he has re- 

 course to the indications afforded by maps, which are very often 

 erroneous. He has committed this error in regard to the 

 Apennine chain. 



The study of all the possible intersections of M. de Beau- 

 mont's twelve or thirteen systems of elevation, would be most 

 useful in order to get a standard point of departure ; and to see 

 if, in the known parts of the earth, there are no similar accidens 

 which do not belong to any of the cases established a priori, 

 and which would render necessary the establishment of some 

 additional epoch of revolution. 



According to M. de Beaumont, a paralleUsm of direction in 

 the dislocations of various countries had been long remarked. 

 Amongst the older writers, I shall rest satisfied with mentioning 

 Stenon, who wrote in 1667 (De Solido, &c.), and Bernhard 

 Varenius, who, in 1712, published his Geographia Generalis in 

 qua afFectiones generales Telluris explicantur (Cambridge, 8vo). 

 Werner, and after him Schmidt (Theorie d. Verschiebungen 

 alterer Gauge, Frankfurt, 1810), applied the idea to the dis- 

 tinction of metalliferous veins ; Humboldt did so to various 

 chains of Europe ; Jameson to the mountain ranges of Scotland ; 

 Hausmann, in 1808, to the mountains of Scandinavia, (Denk- 

 schriften d. Acad. v. Miinchen.) ; M. Brochant to the Jura 

 range, and also to the Alps ; Heim to the hills of central Ger- 

 many, and Von Buch, in 1824, to the chains of central Europe. 

 (Leonhard's Taschenbuch). " Cette notion de la contempor- 

 aneite des fractures paralleles entre elles et de la difference d'age 

 des fractures des directions differentes," (p. 621), was also an 

 axiom of the school of Freiberg ; " rien n'etait plus naturel,"*' 

 adds M. de Beaumont, " que de Songer a la generaliser, et a 



