The universal geography : earth and its inhabitants

LAKES AND EIVEES OF PATAGONIA. 885
The Chubut axd Sexgier Rivers.
A much smaller volume is sent down by the Chubut, a river whose very exis-
tence was stiU unknown in 1833, unless it is to be identified with the Eio
Camerones of the old maps. Its farthest headwaters descend from the Cordillera
south of Nahuel-Huapi, and once formed, the river flows without many windings
through an "accursed land" of rocks and shingle, where affluents are rare on. the
south, and altogether absent on the north side.
The Senguer (Singerr, Senguel), chief tributary of the Chubut, rises on the
Andes near the sources of the Aysen, and, according to a native report mentioned
by Moreno, the Senguer (Chubut) forms with the Aysen a continuous waterway
across the Continent from the Atlantic to the Pacific. It first traverses a splendid
region of pastures and woodlands, a veritable Patagonian oasis ; then, being
deflected to the north-east by a barrier of rocks and other obstacles, its turbid
current expands in a vast shallow basin which rises and falls with the seasons,
and which, according to Fontana, stands about 1,000 feet above sea-level.
This basin, composed of the lakes Colhue and Musters, which are almost com-
pletely separated by a meridional chain of volcanic crests, is fringed on the south
side by marshy tracts flooded by its overflow. Beyond this morass, where it
loses a third of its volume, the Senger continues its course to the Chubut,
without, however, contributing sufficient to make it navigable at all times. Boats
can ascend with the flow, but they find only five or six feet of water in its bed
except during the melting of the snows.
The Rio Deseado.
The Rio Deseado, " Desire," discovered by Cavendish in 1586, falls into the
estuary of the same name south of the Gulf of St. George. It is even less copious
than the Chubut, although it also traverses nearly the whole breadth of the
Patagonian peninsula. Lake Buenos Ayres, which probably at one time fed the
Deseado, has no longer any outlet, and now sleeps in its circular basin like a
flooded crater.
In these Patagonian regions, which were formerly far more humid than at
present, travellers have observed several other basins, which are now dry, but
which were at one time filled with water, as is evident from the alluvial deposits
on their beds.
At its mouth the Deseado is usually a mere rivulet, with a volume reduced at
times to a few cubic feet per second, but after the rains it is swollen to the
proportions of a considerable river. It reaches the coast at the head of an
elongated inlet of extremely picturesque aspect, which extends for a distance of
some 24 miles in the direction from west to east. The coast line is greatly
diversified with numerous islands and islets, reefs and headlands, bays, ravines,
and glens. All the eminences are extinct volcanoes, which were probably still
VOL. XIX. c c