ENTEKING THE GBANITE. 81 
hour, and emerge into a more open portion of the canon, where high hills 
and ledges of rock intervene between the river and the distant walls. Just 
at the head of this open place the river runs across a dike : that is, a fissure 
in the rocks, open to depths below, has been filled with eruptive matter, and 
this, on cooling, was harder than the rocks through which the crevice was 
made, and, when these were washed away, the harder volcanic matter 
remained as a wall, and the river has cut a gate-way through it several hun 
dred feet high, and as many wide. As it crosses the wall, there is a fall 
below, and a bad rapid, filled with boulders of trap; so we stop to make a 
portage. Then on we go, gliding by hills and ledges, with distant walls in 
view; sweeping past sharp angles of rock; stopping at a few points to exam 
ine rapids, which we find can be run, until we have made another five 
miles, when we land for dinner. 
Then we let down with lines, over a long rapid, and start again. Once 
more the walls close in, and we find ourselves in a narrow gorge, the water 
again filling the channel, and very swift. With great care, and constant 
watchfulness, we proceed, making about four miles this afternoon, and camp 
in a cave. 
August 14. At daybreak we walk down the bank of the river, on a 
little sandy beach, to take a view of a new feature in the canon. Hereto 
fore, hard rocks have given us bad river; soft rocks, smooth water; and a 
series of rocks harder than any we have experienced sets in. The river 
enters the granite ! * 
We can see but a little way into the granite gorge, but it looks threat 
ening. 
After breakfast we enter on the waves. At the very introduction, it 
inspires awe. The canon is narrower than we have ever before seen it; the 
water is swifter; there are but few broken rocks in the channel; but the 

walls are set, on either side, with pinnacles and crags; and sharp, angular 
buttresses, bristling with wind and wave polished spires, extend far out into 
the river. 
Ledges of rocks jut into the s'tream, their tops sometimes just below 
* Geologists would call these rocks metamorphic crystalline schists, with dikes and beds of granite, 
but we will use the popular name for the whole series granite. 
11 COL 
