THE KAPEDS OF THE MADEIRA AXD THE MAMORlS. 55 
The cUffereuce of declivity betAvecn the smooths above and below, 
on an average level, is 4-13 English feet; the dimsion in the left 
channel is at 1G4 feet, that on the right about six times that distance. 
Here the canoes must be unladen, and then’ contents can-ied to a point 
on the left bank above the rapid, while the empty vessels are towed there 
tlirough a labyrinth of intricate channels, amidst lai’ge granite blocks, 
close to the edge of the right bank. 
Over a large shoal and some flat islands, we could sec aheady from 
Macacos, the next not very considerable rapid, the rising water-spray of 
the mighty fall of Theotonio. Between low hills running down to the 
water’s edge on both sides, the river has holloAVod a coiu'se of 2,300 feet 
in breadth, through which it dashes at furious speed, terminating in a 
majestic fall 36 feet high. 
Not only the cargo, but the canoes themselves, had to be transported 
hence on land for more than 760 yards to the quiet water above the 
fall, a heavy task which took us three complete days of hard labour, our 
Mojos working with right good will, although the passage of the boats 
was facilitated by cylinders being placed under them. No wonder, by 
the way, that one or the other of the canoes, after encountering so rough 
a transport, was so damaged as to requhe immediate repair, caulking, and 
even the addition of new ribs. 
On the ridge of a rocky hill on the right bank, we saAV the remains of 
some walls, covered almost completely b}^ shrubs, low palms, and thomy 
torch-thistles. They date from 1753, when Theotonio Gusmao, by the 
direction of the Portuguese Government, here founded, in a very good 
position for defence, a military post, which was, however, soon abandoned. 
At that time the commerce with the province of Mato Grosso having 
acquired a Iresh impulse from the erection of the Forto do Principe da 
Bcira on the Guapore, an impulse strengthened by the explorations in 
1767 and 1780, such Dcstaeamentos (or military posts) were of the first 
necessity on that water road, as well for securing the supply of provisions, 
and for the protection thus gained against the wild Indians, as for the 
assistance rendered by the soldiers in the hard work near the rapids. 
The material of the hills we foimd to bo the same, more or less, over 
the whole region of the rapids ; gneiss, mth mostly a very pronoxmeed 
stratification, and alwaj^s the same run. We examined it more closely, 
expecting to find, accorthug to the theory of Agassiz, numerous erratic 
boulders of diflerent composition lying on the regularly formed rock. 
