scanty rain-water; and consequently on the line where the
igneous and sedimentary formations unite, some small
springs (most rare occurrences in Patagonia) burst forth;
and they could be distinguished at a distance by the
circumscribed patches of bright green herbage.

April 27th. -- The bed of the river became rather narrower
and hence the stream more rapid. It here ran at the rate
of six knots an hour. From this cause, and from the many
great angular fragments, tracking the boats became both
dangerous and laborious.


This day I shot a condor. It measured from tip to tip
of the wings, eight and a half feet, and from beak to tail,
four feet. This bird is known to have a wide geographical
range, being found on the west coast of South America,
from the Strait of Magellan along the Cordillera as far as
eight degrees north of the equator. The steep cliff near the
mouth of the Rio Negro is its northern limit on the Patagonian
coast; and they have there wandered about four
hundred miles from the great central line of their habitations
in the Andes. Further south, among the bold precipices
at the head of Port Desire, the condor is not uncommon;
yet only a few stragglers occasionally visit the sea-coast.
A line of cliff near the mouth of the Santa Cruz is
frequented by these birds, and about eighty miles up the
river, where the sides of the valley are formed by steep
basaltic precipices, the condor reappears. From these facts
it seems that the condors require perpendicular cliffs. In