PASSAGE OF THE UPPER CATARACT. 953 
as much of latitude. The thermometer during the 
night indicated from 80° to 84°, and in the day 86°. 
The water of the river was 81°7°, and that of a 
spring 82°. 
Having spent some days at the mission of May- 
pures, the travellers embarked at two in the after- 
noon in the canoe procured at the turtle island, 
which, although considerably damaged by the care- 
lessness of the Indians, was judged sufficient for the 
long voyage they had yet to perform. Above the 
great cataracts they found themselves as it were ina 
new world. Toward the east, in the extreme distance, 
rose the great chain of the Cunavami mountains, 
one of the peaks of which, named Calidamini, re- 
flects at sunset a reddish glare of light. After encoun- 
tering one more rapid they entered upon smooth 
water, and passed the night in a rocky island. 
On the 22d they set out at an early hour. The 
morning was damp but delicious, and not a breath 
of wind was felt ; a perpetual calm reigning to the 
south of the cataracts, which Humboldt attributes 
to the windings of the rivers, the shelter of moun- 
tains, and the almost incessant rains. In the valley 
of the Amazon, on the contrary, a strong breeze 
rises every day at two in the afternoon, which, how- 
ever, is felt only along the line of the current. It 
always moves against the stream, and by means of 
it a boat may go up the Amazon under sail a length 
of 2590 miles. The great salubrity of this district 
is probably owing to the gale. They passed the 
mouths of several streams, and admired the gran- 
deur of the cerros of Lipapo, a branch of the cordil- 
lera of Parime, the aspect of which varied every hour 
of the day. At sunrise, the dense vegetation with 
