Ch. XXIX.] 



CALDERA OF PALMA. 



495 



the flanks of the mountain, a short distance below the summit, shallow 

 at first, but getting deeper as they descend, and becoming at the same 

 time more numerous, as in the cones of Java before mentioned. 



So unbroken is the precipitous boundary-wall of the Caldera, except at 

 its southeastern end, where the torrent which drains it through a deep 

 gorge (6, b', fig. 643), issues, there is not even a footpath by which one 

 can descend into it save at one place called the Cumbrecito (e, map, fig. 

 642, p. 494). This Cumbrecito is a narrow col or watershed at the height 

 of about 2000 feet above the bottom of the Caldera, and 4000 above the 

 sea, and situated at the precise limit of two geological formations presently 

 to be mentioned. This col also occurs at the level where, in other parts 

 of the Caldera, the vertical precipices join the talus-like, rocky slope, cov- 

 ered with pines. The other or principal entrance by which the Caldera 

 is drained, is the great ravine or barranco, as it is called (see b, b\ fig. 643), 

 which extends from the southwestern extremity of the Caldera to the sea, 



Fig. 643. 



Map of the Caldera of Palma and the great ravine, called " Barranco de las Angustias." From 

 the Survey of Capt. Vidal, E. N., 1837. Scale, two geographical miles to an inch. 



