304 COSMOS. 



ribs, as the mountain is bare of forest trees and clothed with 

 grass." According to the measurements given by Jung- 

 huhn, 93 the number of ribs increases by division in propor- 

 tion as the declivity decreases. Above the zone of 9000 feet 

 there are, on Gunung Sumbing, only about 10 such ribs ; at 

 an elevation of 8,500 feet there are 32 ; at 5500 feet, 72 ; and 

 at 3,000 feet, more than 95. The angle of inclination at the 

 same time diminishes from 37 to 25 and 10|. The ribs 

 are almost equally regular on the volcano Gunung Tengger 

 (8702 feet), whilst on the Gunung Ringgit they have been 

 disturbed and covered 94 by the destructive eruptions which 

 followed the year 1586. The production of these peculiar 

 longitudinal ribs and the mountain fissures lying between 

 them, of which drawings are given, is ascribed to " erosion 

 by streams." 



It is certain thac the mass of meteoric water in this tro- 

 pical region is three or four times greater than in the tem- 

 perate zone, indeed the showers are often like waterspouts, 

 for although, on the whole, the moisture diminishes with the 

 elevation of the strata of air, the great mountain cones exert 

 on the other hand a peculiar attraction upon the clouds, 

 and, as I have already remarked, in other places, volcanic 

 eruptions are in their nature productive of storms. The 

 clefts and valleys (Barrancos), in the volcanoes of the Canary- 

 Islands, and in the Cordilleras of South America, which have 

 become of importance to the traveller from the frequent 

 descriptions given by Leopold von Buch 95 and myself, because 

 they open up to him the interior of the mountain, and some- 

 times even conduct him up to the vicinity of the highest 

 summits, and to the circumvallation of a crater of elevation, 

 exhibit analogous phenomena ; but although these also at 

 times carry off the accumulated meteoric waters, the original 

 formation of the barrancas 96 upon the slopes of the volcanoes 



93 Junghuhn, Bd. ii. s. 241 246. 



94 Op. cit. sup. s. 566, 590 and 607609. 



95 Leopold von Buch, Phys. Besckr. der Canariscken Inseln, a. 206. 

 218, 248, and 289. 



96 Barranco and Barranca, both of the same meaning, and suffi- 

 ciently in use in Spanish America, certainly indicate properly a water- 

 furrow or water-cleft : la quiebra que haceu en la tierra las corrientea 

 delas aguas ; "uua torrente que hace barrancas;" but they also indi- 



