VERTICAL BEDS OF GRANITE. 



61 



convinced nnyself that it is composed entirely of magnificent plates 

 (lames) of granite, perpendicular to the horizon, and ranging from 

 east to west. 1 had, formerly, been induced to believe, that these 

 plates were folded round the peak, like ^the leaves of an artichoke, 

 but this was an optical illusion, when seen imperfectly from below : 

 here, where the eye could as it were, dart down into the interior struc- 

 ture of the mountain, the plates of rock appeared regularly parallel 

 in a direct line." " I was also," says Saussure, " particularly desirous 

 of ascertaining, whether the vertical beds were composed of the same 

 substances at their summits as at their bases, where 1 had so frequently 

 inspected them ; and, I am perfectly satisfied, from actual exami- 

 nation, that they preserve the same nature through their whole ex- 

 tent, and are the same at the summit as below."^ T^oyages dans 

 les Alpes, tome iv. 



The inference drawn by Saussure, respecting the vertical position 

 of the beds of granite that compose a principal part of Mont Blanc 

 and the adjoining mountains, is, that they were originally horizontal, 

 and have been subsequently elevated by some tremendous convul- 

 sion of nature. The summit of Mont Blanc, he says, must, at one 

 time, have been more than two leagues under the surface. To the 

 same convulsion he attributes also, the position of the escarpments or 

 steep sides of the rocks which for a considerable extent, face Mont 

 Blanc, and then turn from it in an opposite direction. This would 

 be the case, had the surface of the globe been broken and elevated 

 in the manner he supposes. There is a circumstance stated by 

 Saussure, which tends strongly to confirm, if not absolutely to prove 

 the truth of his hypothesis. Some of the vertical beds of rock, ad- 

 jacent to the granite contain round pebbles, boulders, and water worn 

 pieces of the lower rocks. See observations on these beds, Chap. 

 IV. Jt is impossible to conceive that those rounded fragments could 

 have been placed in a vertical position ; for, if they be really pebbles 

 and boulders, the beds on which they occur must, originally, have 

 been nearly horizontal. Now as these beds are, at present, placed 

 between others which are also vertical, and in the same range, it fol- 

 lows, that the whole have been overturned and thrown up, at a period 

 subsequent to their formation. f 



The Himmaleh Mountains in the centre of Asia, rise ten thou- 

 sand feet higher than any mountains in the Alps, but, where their 



* The extreme fatigue and exhaustion which Saussure experienced during the 

 ascent of Mont Blanc, is supposed to have abridged the life of this active and in- 

 telligent philosopher. It may amuse the reader to be told, that Saussure, during 

 his excursions in the Alps, wore a full dressed scarlet coat and gold laced hat. 

 He informs us, that when he was seated on Mont Breven, the lace of his hat at- 

 tracted the electric fluid from a passing cloud, and occasioned a hissing sound. 

 Tempora mutantur, et nos, (^c. 



t Saussure says expressly, that the boulders in the rocks near Mont Blanc, are 

 precisely similar to the boulders on the shores of the lake of Geneva. 



