between the 18th and 19th
parallels, the more prominent are the Frailes which forms the eastern
rampart of the great central plateau and which is celebrated for its
mineral deposits, the Chichas which runs south from the vicinity of
Potosi to the Argentine frontier, and the Livichuco which turns
south-east and forms the watershed between the Cachimayo and Pilcomayo.
The more prominent peaks in and between these ranges are the Asanaque
(16,857), Michaga (17,389), Cuzco (17,930), Potosi (15,381), Chorolque
(18,480) and Tuluma (15,584). At the southern extremity of the great
plateau is the transverse Serrania de Lipez, the culminating crest of
which stands 16,404 ft. above sea-level. The eastern rampart of the
Bolivian highlands comprises two distinct chains--the Sierra de
Cochabamba on the north-east and the Sierra de Misiones on the east.
Between these and the Cordillera Oriental is an apparently confused mass
of broken, intersecting ranges, which on closer examination are found to
conform more or less closely to the two outside ranges. These have been
deeply cut by rivers, especially on the north-east, where the rainfall
is heavier. The region enclosed by these ranges is extremely rugged in
character, but it is esteemed highly for its fertile valleys and its
fine climate, and is called the "Bolivian Switzerland." Lying wholly
within the tropics, these mountain masses form one of the most
interesting as well as one of the most imposing and difficult regions of
the world. At their feet and in their lower valleys the heat is intense
and the vegetation is tropical. Above these are cool, temperate slopes
and valleys, and high above these, bleak, wind-swept passes and
snow-clad peaks. West of the Cordillera Oriental, where special
conditions prevail, a great desert plateau stretches entirely across one
corner of the republic. Apart from the Andean system there is a group of
low, broken, gneiss ranges stretching along the east side of Bolivia
among the upper affluents of the Mamore and Guapore, which appear to
belong to the older Brazilian orographic system, from which they have
been separated by the erosive action of water. They are known as the
Sierras de Chiquitos, and are geologically interesting because of their
proximity to the eastern projection of the Andes. Their culminating
point is Cerro Cochii, 3894 ft. above sea-level, but for the most part
they are but little more than ranges of low wooded hills, having in
general