228 



ILLUSTRATIONS OF THE 



d. that I d 



mean to fpeak with abfo 



lute precifion, or to deny the exiflence of 



The refiilt given is only a 

 deduced from obfervations 



local irrco;ularities. 

 kind of average, 



hardly fufceptible of great exa6lnefs, and not 

 yet fufficiently multiplied to give to th^ con- 

 clufion all the accuracy it may attain. 



206. This tendency of the primary llrata to 

 take a uniform diredion, has alfo been obferved 

 in other countries. Sauffure remarked in the 

 Alps, that the beds of fchiftus are generally pa- 

 rallel to the chains of mountains compofed of 

 them * ; and this remark is probably applica- 

 ble to all mountains confiding of primary llrata. 

 The general direction, therefore, of the fchiftus 

 of the Alps, rauft be confined between W. 10*^ S. 

 and W. 40" S, In the Pyrenees, the diredion 

 of the flrata is about V/. N. W f. If SaufTure's^ 

 rule may be depended on, the fchiftus of the 

 Altaic, and moft of the other great chains in 

 the old continent, are in diredions that run con- 

 fiderably to the fouth of weft. The Ourals, 

 and perhaps fome other of the northern chains, 

 are however entirely different^ In the Ourals, 

 as we learn not only from the general diredion of 



the chain, but from a fedion of it in the loth vo- 



luaie 



I 



* Voyages aux Alpes, torn. i. § 577. 



t EiTai fur le Mineralogie des Pyrenees, 



