1883.] Geography and Travels. 1055 
than the Thames just above London the fissure must be very 
dee 
To the north-west of the western cordillera lie two rivers which 
repeat, on a smaller scale, the features observed in the Cauca and 
Patia. These are the Atrato and the San Juan, the former flow- 
ing northward into the Atlantic, the latter southward into the 
Pacific. Though much has been written about the Lower Atrato, 
the upper portion of the valley is less known. According to Mr, 
White, the river is navigable not only to Quibdó, where it is 250 
yards wide, but to Llord, which is in the midst of the upper 
basin, a region wel! adapted for agriculture, hilly but not moun- 
tainous, and covered with virgin forest. The higher portions of 
this valley (4000 to 5000 feet) are very healthy, and are diversi- 
fied by open prairie. Here every kind of tropical produce may 
be cultivated, as the temperature ranges from 60° to 80°, caou- 
tchoue and the ivory nut are abundant, and copper, coal and gold 
are met with. 
_ The opening of a ship canal across the isthmus will render the 
lands of this elevated yet fertile region accessible, and the colo- 
nists are at hand in the neighboring State of Antioquia. 
workings, it is probable that the trees are not more than 200 or 
300 years old, and that at the time of the Spanish conquest much | 
open land existed here, occupied by an agricultural Indian popu- 
lation, now practically extinct. 
Mr. White has ascended the Cerro Torra, a peculiar mountain 
about twenty-seven miles east of Novita, on the San Juan. This 
mountain, which abruptly terminates a ridge of hills, and rises 
ut 12,600 feet above the sea, had not before been ascended, 
Its western face is a horse-shoe shaped amphitheatre which slopes 
regularly for half a mile or so, and then ends in a horse-shoe 
shaped precipice, down which hundreds of streams fall a sheer 
3000 feet, to collect at its foot into the River Surama. The moun- 
tain consists of clay and mica slates, probably Jurassic, while the 
igneous rock, the eruption of which upheaved it, is syenitic 
granite, 
_ Avery large proportion of the platinum produced in the world 
1s obtained from the Upper San Juan. 
VOL. XVIL.—NO. x $ 70 
