31 



" I have been attentive to the parallelism of beds. Residing on 

 mountains of stratified rocks, where this phenomenon is con- 

 stant, examining the direction and dip of primitive and transition 

 beds, from the coast of Genoa across the chain of the Bochetta, 

 the plains of Lombardy, the Alps of St. Gothard, the table-land 

 of Suabia, the mountains of Baireuth, and the plains of North- 

 ern Germany, I have been struck, if not with the constancy, at 

 least with the extreme frequency of the directions from south- 

 west to north-east. This inquiry, which I thought would lead 

 naturalists to the discovery of a great law of nature, at that time 

 interested me so much, that it became one of the principal rea- 

 sons for my voyage to the equator. When I arrived on the 

 coast of Venezuela and passed over the lofty littoral chain and 

 the mountains of granite-gneiss that stretch from the Lower 

 Oronoco to the basin of the Rio Negro and the Amazon, I re- 

 cognized again the most surprising parallelism in the direction 

 of the beds ; that direction was still north-east." 



Unfortunately, in consequence of Werner's theory, Humboldt 

 wrote the above under the impression that the gneiss and schis- 

 tose rocks were similar to sedimentary beds ; hence he confounds 

 the lamination of the former with the divisional planes of the 

 latter. 



" When we examine," says M. Boue, " with a compass the 

 position of mineral masses in Scotland, and endeavour to stop 

 at general facts, we perceive that the direction of the beds is 

 constant, and corresponds with that of the chains from south-west 

 to north-east, but that the dip varies according to local circum- 

 stances." 



According to Von Buch and other continental geologists, the 

 directions of the lamination of the crystalline rocks in Sweden 

 and Finland are from south to north, varying occasionally to- 

 wards the east. In Mexico the laminated structure is princi- 

 pally towards the north-west ; but in the plains it is frequently 

 found due north and north-east. In the United States its gene- 

 ral direction is similar to that of South America, i. e. from south 

 to north, but presenting numerous contortions, and thus causing 

 local variations in the direction, either towards the east or west, 

 according to the nature of the local resistance. 



" The direction of primitive and transition beds " (gneiss and 



