omerate were
seen standing out like church spires in this desert of rock, varying
in colour from red to lead gray. Once we caught sight of a stretch of
the Rio Aros deep down in a narrow, desolate valley, some 3,000 feet
below us. The geological formation of the region is mostly volcanic;
then follows conglomerate, and on the high points porphyry appears.

We camped on the crest of the eastern side of the Rio Chico Canon,
in an ideal place with bracing air. A fine, sloping meadow afforded
quite an arcadian view with the animals peacefully grazing and resting;
but looking westward, the eye revelled in the grand panorama of the
sierra. The two sides of the Rio Chico Valley rise here evenly from
the bottom of the gorge so as to suggest the letter V. In many places
its brow is overhung by precipitous cliffs, and further down still
more steeply walled chasms yawn up from the river bed.

My chief packer now became ill from the effects of poison ivy. He was
one of those unfortunate individuals who are specially susceptible to
it. According to his own statement it sufficed for him to pass anywhere
near the plant, even without touching it, to become afflicted with the
disease. In this case he did not even know where he had contracted it,
until the cook showed him some specimens of the plant near an oak tree
close by the kitchen tent. The poor fellow's lips were badly swollen;
he had acute pains in his eyes, and felt unable to move. Sometimes, he
said, the disease would last ten days, and his skin become so tender
that he could not endure the weight or contact of his clothes. But
by applying to the afflicted parts of his body a solution of baking
soda in water, I was able not only to relieve his suffering, but to
enable him, after two days, to continue with us on our journey.

In the meantime we had investigated some caves in the conglomerate
of the steep canon side, about 250 feet above the bottom of the
gorge, and rather difficult of access. The house group occupied the
entire width of a cave, which was eighty feet across, and there was
a foundation wall made of stone and timber underneath the front
part. The walls were made of stone, with mortar of disintegrated
rock that lined parts of the cave and were plastered inside and out
with the same material. Lintels of wood were seen in the windows,
and rows of sticks standing in a perpendicular position were found in
two of the walls inside of the plastering. On one side of the c