Geological Derincation of South America. 31' 



the angle of inclination (less than 90°) which it makes \\-ith 

 the earth's axis stands towards the noi th-ea-t. The rising is 

 more constant than the tailing, especiallv in the simplemoun- 

 tains (argillaceous schist, hornblend schist), or in the com- 

 pound mountains with fewer crystallized grains, such as the 

 micaceous schist. In granite (it is, however, found very re- 

 gularly stratified rismg in the league 3 — 4, and falling- to- 

 wards the nordi on the Schneeki)pfe, the Ochsenkopfe, the 

 Sicbcngebirge, and the Pyrenees,) and in the gnieis the at- 

 traction of the crystallized mixed parts to each other seem* 

 to have prevented the regular stratification ; therefore more 

 coincidence is found among the micaceous and argillaceous 

 schist, and these first led me to the idea of the law of risincr 

 during my tour to the Fichtelbcrg and the Thuringian fo- 

 rest. Since that time I have examined with great care 

 the angle of the strata of other original mountains in other 

 parts of Germany, in Svvisserland, Italy, the southern 

 parts of France, and the Pyrenees, and lately in Gallicia. 

 Mr. Freiesleben, whose labours have been of so much ser- 

 vice to geology, assisted me in this examination ; and we 

 were astonished at the uniformity in the rising and falling 

 of the mountains which we found at each step on one of 

 the highest cordilleras of the earth, the Alps of Savoy, the 

 Valais, and the Milanese, 



An examination of this phaenomenon, and of the identity 

 of the strata, was one of the principal objects when I under- 

 took a voyage to America. A measurement of the angles 

 which I liave hitherto made on the Cordillera of Venezuola 

 iiid Parima gave again the result of liiy observations in 

 Europe in the cliain of the micaceous schist mountains of 

 Cavaralleda as far as Rio Mamon ; on the Silla de Caracas at 

 tile height of 1000 toises ; of the Rincon del Diablo, on. 

 mount Guigue ; in the islands in the beautiful lake of Va- 

 lencia, which has almost the same elevation as the lake of 

 Geneva, at the boundaries of the isthmus of Maniouare and 

 Chupariparu ; on the hornblend schist which appears unco- 

 vered in the streets of the capital of Guyana, and also in the 

 Cataracts, and on the stratified granite at the foot of the 

 Duida. Every where the strata form an angle of 50** witH 

 the meridian (in the league 3 — 4 by the Saxon compass) as 

 they rise from the north-cast to south-west, and fall about 

 ixom Co to 80 towards the north-west. 



Thii great comcidence in the old and new world must 



excite serious considerations. It exhibits a very important 



geological fact. After so many observations which I have. 



made iu places so far distant from each otlier, it can no 



3 longer 



