ome obstacle. I feared that we should
soon encounter nasty rapids. Watching the sky, I was generally able to
foretell what was ahead of us in the river. In fact, a pretty mackerel
sky, particularly to the north-west, showed me that the water of our
river must be breaking up considerably, either in rapids or waterfalls,
in order to produce sufficient moisture in the air to cause the
accumulation of those cloudlets. I always noticed that wherever there
were heavy rapids farther down clouds of more or less magnitude formed
directly above them at a comparatively low elevation, and remained there
owing to the perfect stillness of the air.

On the night of July 14th the cold was felt intensely by my men, the
thermometer actually showing a minimum of 38 deg. F.

During the night my men had a great excitement. A large pachyderm, an
_anta_ (_Tapirus Americanus_) inquisitively came in the midst of our
camp. It was evidently as much astonished at seeing us as we were in
discovering its presence. My men had been firing their cartridges away
during the day at rocks, at fish in the river, and so on, so that when
their rifles were really needed the magazines were all empty, and gave
the _anta_ plenty of time to hop away gracefully into the darkness of the
forest.

I had given orders to them to keep watch all night, as a precaution
against an attack from the Indians, but my orders were, as usual,
disobeyed. Personally, I took the first watch every night, sitting up
till 2 a.m., which time I occupied in writing up my notes, working out
computations of astronomical observations, classifying the botanical and
geological specimens collected during the day, and replenishing my
cameras with new plates.

My men had eaten up all the supply of beans (_feijao_) I had purchased at
Diamantino, and therefore even the cook could not be kept awake during
the night. The first rubber collector I had picked up when coming down
the Arinos was now our cook, and diabolical indeed was his _cuisine_.
Several times already his life had been in danger from the angry attacks
of his companions, the quantities of pepper he sprinkled on everything he
cooked causing us all to cough sometimes for half-hours at a time. He was
very fond of pepper himself, and could not understand why none of us
liked it.

During the night we still had a mackerel sky, covering one-third of the
sky vault, and a clear triangle of mist, the apex of which was to the
west, extending t