602 Extracts from the Minute Book of the Geological Society. 
larger proportion of boulder-stones, rising to the height of about 
one hundred feet. Near the water, the clay assumes the appearance 
of angular masses of stone, whose surfaces appear to be washed 
with a red ochry matter. 
At the Kettle falls, the country rises to a less considerable height 
above the river. The bank is now about twenty-five feet high 
and very sloping. The river here runs through numberless chasms 
formed by a multitude of rocky islands, of which the greater part 
are perfectly bare of vegetation, though some are covered to the 
top with herbage, and two or three have large trees growing in 
perfection upon them.* Presently afterwards the channel being 
narrowed suddenly, to the width of one hundred yards, a prodigious 
rush of water forces itself through a horrid opening in the rocks. 
The portages at the Kettle falls amount together in a direct 
line to one-third of a mile. At the second portage we carried 
every thing one hundred and eighty-two yards upon the north side 
of an island, where numerous excavations of a circular form are 
seen in the solid rock. It is from the form of these excavations 
that the Kettle falls have received their name. The origin of 
these excavations may probably be traced to boulder-stones, which 
lodged in cavities, set in motion by the water, and aided by the attri- 
tion of sand, wear themselves thin hollow cups in the rock. The 
rocks upon this island consist of whinstone or granite. 
Towards the upper portage the ground rises to the height of 
one hundred feet above the river, and is remarkably steep to the 
distance of one-third of a mile above the portage. 
On our return, when about the middle of the river, below the 
great limestone fall, we observed a dry shoal two or three hundred 
* No. 17719, Coll. Geol. Soc. brought by Mr. Kerney, from this part of the rirer, 
consists of hornblende slate. 
