there violent eddies which
knocked the canoe about in a most alarming manner soon after we had
descended a short rapid of some steepness.

Our baggage was simply soaked owing to the amount of water we had shipped
on various occasions during the day. We saw ahead of us, only a short
distance off, a rapid of some magnitude. We decided to halt at four
o'clock in order that we might go and explore on foot along the bank and
see whether the canoe could be navigated down, or if we had better
unload her and let her down with ropes. We cut a space in the forest,
which was there thick, in order to make our camp. We spread all our
things to dry during the night. The air was stifling--we had a minimum
temperature of 73 deg. F. (July 18th).

I took the accurate elevation of the camp with the hypsometrical
apparatus, water boiling at that spot at 210 deg..4, with the temperature of
the air 73 deg. F.; altitude 1,113 ft. above sea level. I also took
observations for latitude and longitude: Lat. 11 deg. 17'.5 S.; long. 57 deg. 37'
W. We had to remain the entire morning in order to cut a way through the
forest and take part of the most valuable baggage on men's backs until a
point below the rapids was reached.

We named that place Camp Jahu, as we caught there several enormous fish
of that name.

In a reconnaissance we made we found that from Camp Jahu we had to take
the canoe along among innumerable rocks scattered in the only navigable
channel on the north side of a basin 700 m. wide, with a large island 350
m. wide--Sarah Island--on the southern side of the bay, and another
smaller island almost in the centre of the basin. There was a drop 2 ft.
high--a regular step--in a barrier of sharply-pointed rocks. We had some
two hours' hard work in order to get the canoe safely down. The rocks
were so close together that we could not find a passage large enough for
the canoe, and we actually had to pull her out of the water over some
rocks and then let her down gently on the other side.

After leaving that great _pedraria_ there was a clear basin 250 m. wide,
ending where two enormous heaps of rock formed a giant gateway. An
island, 80 m. wide--Rebecca Island--was found near the left cluster of
rocks. Another small island had formed close to the right of the river.
We descended by the north-easterly passage, only 4 m. wide, where the
current was extremely swift but the rapid comparatively easy to
negotiate.

We then followed the cha