1852.J 
CURIOUS ROCKS. 
353 
rock, apparently sandstone, and numerous veins and 
dykes, which often cross each other in three or four sets. 
The rocks are, in many places, so broken and cleft verti- 
cally, as to appear stratified and thrown up on end. The 
rounded form and concentric arrangement, observed in 
the Rio Negro, is here also constantly met with. The 
interstices of the rounded and angular masses of rock 
are often filled with a curious volcanic substance, which 
outwardly resembles pitch, but consists of scoriae, sand, 
clays, etc., variously cemented together. 
On the iOth we passed the “Tapioca,” “Tucano” 
(Toucan), “ Tucunare ” (a fish), “ Uaracu pinimi ” (a 
fish), and “ Tyeassu ” (Pig) caxoeiras. The first was 
very bad, and both difficult and dangerous to pass ; it 
consisted of many distinct falls among huge masses of 
rock. At one place the canoe remained stuck fast, amidst 
foaming waters, on the very edge of a fall, for nearly an 
hour; all the efforts of the Indians could not move it 
forward. They heaved it over from one side to the 
other, but with no effect ; till I began to despair of get- 
ting out of the difficulty before night. At last the canoe 
suddenly moved on, with apparently not so much force 
as had been before applied to it ; but my Indians, being 
of several nations, did not understand any common lan- 
guage, and it was impossible to get them to act in con- 
cert, or obey any leader. It was probably some chance 
combination of forces, that at last extricated us from 
our unpleasant situation. At this fall, on the rocks, 
were very numerous figures, or picture-writings, and I 
stopped to make drawings of them ; of which I had by 
this time a rather extensive collection. 
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