ACROSS UNKNOWN SOUTH AMERICA 
in reply the horn of the seringueiros at Porto Velho. 
Judging by the sound, the distance could not have been 
more than a few hundred metres, although we had 
travelled some six thousand metres down stream. 
For the first time I noticed swallows flying swiftly 
over the river, close to the water. Another easy corrideira 
was encountered. When we had been out several hours 
my men were already beginning to get into the right way 
of paddling, and Alcides was commencing to understand 
the capricious mysteries of the steering gear. 
On account of my men’s inexperience, and due credit 
being given to the current, we went at the rate of thirteen 
kilometres an hour. Innumerable were the rubber trees 
all along the banks. Occasionally small sand beaches 
were met with. Here and there a fallen, giant tree 
obstructed part of the river. Families of ariranha (Lutra 
brasiliensis) played in the water. The pretty little ani¬ 
mals, not unlike otters, raised their heads above water, 
and, hissing loudly, frequently came to attack the canoe. 
They were extraordinarily brave. They were greatly 
attracted by the vivid red of the British flag, which in 
their imagination suggested blood. They became wildly 
excited when I waved the flag at them, and when I placed 
it near the water they would charge the canoe angrily, so 
that two or three times my men were able to kill them 
by striking them on the head with the heavy, wooden 
paddles. 
The river was at its lowest when I descended it, which 
made it all the more difficult for us, as we were treated 
to innumerable small rapids which would otherwise have 
been entirely covered over with water. A great island, 
eighty metres long, of pebbles and beautiful crystals was 
passed in the centre of the stream, which there formed two 
channels: one entirely blocked by fallen trees and accumu¬ 
lated rolling material, the other, forty metres wide, very 
deep and swift. 
18 
