ACROSS UNKNOWN SOUTH AMERICA 
— we had a minimum temperature of 73° Fahrenheit 
(July seventeenth). 
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° Fahrenheit; 
altitude 1,113 feet above sea level. I also took observa¬ 
tions for latitude and longitude: latitude 11° 17'.5 south; 
longitude 57° 37' west. 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 metres wide, with a large 
island 350 metres 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 two feet 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 pe dr aria there was a clear 
basin 250 metres wide, ending where two enormous heaps 
of rock formed a giant gateway. An island, eighty metres 
wide, Rebecca Island, was found near the left cluster of 
rocks, and another small island had formed close to the 
right of the river. We descended by the northeasterly 
passage, only four metres wide, where the current was 
extremely swift but the rapid comparatively easy to 
negotiate. 
We then followed the channel flowing to 350° bearings 
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