I took the accurate elevation of the camp with the hypsometrical apparatus, water boiling at that spot at 210°·4, with the temperature of the air 73° F.; altitude 1,113 ft. above sea level. I also took observations for latitude and longitude: Lat. 11° 17′·5 S.; long. 57° 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 channel flowing to 350° b.m., and after passing innumerable rocks made our camp again before coming to a large rapid which we heard rumbling in that direction.
We had worked hard all that day, and all the progress we had made by sunset was a distance of 2,000 m.—or a little more than one mile.
Alcides, Antonio and I immediately proceeded to cut a trail through the forest from that point down to the end of the rapid, 1,200 m. farther down. Then we proceeded to take all the baggage upon our shoulders—a task which occupied several hours. I was greatly surprised to find that the men did this willingly enough, although they were unaccustomed to carrying and the loads were heavy. They laughed heartily at one another as they struggled under the heavy weights, or trod upon thorns, or were jerked about with knocking against trees—the passage we had cut being necessarily not spacious.
I had not seen my men so jolly for a long time—in fact, I do not remember ever having seen them so jolly. I was in hopes that this state of affairs might last, as it was certainly not pleasant to be travelling in such usually morose company.
During the night we caught an immense jahu, weighing over 50 lb., as well as some 200 lb. of smaller fish. As the bank of the stream was rather high and steep, we had a great deal of trouble to land the larger fish safely. Some of my men had exciting experiences, one man falling into the water on receiving a powerful blow from the tail of the struggling jahu. The scene was a comic one, the terror of the man being amusing to watch.
We carried a great quantity of salt; with it my men set out to preserve the best portions of the fish we had caught—a precaution of which I fully approved.