MODERN ACTION OF RIVERS. 
371 
Stantly tending to increase its dimensions. Within five years, the period of my own observa¬ 
tion, it has been deepened in some places five or six feet, and its southern termination has 
extended several rods. Except during freshets, or the breaking up of winter, the water does 
not flow through the channel c of diagram No. 175, and consequently the wearing action has 
nearly ceased in that direction. The stream, however, is directed against the little island 
seen in the sketch, and will eventually remove it, making for itself a direct channel to the 
gorge below.* 
If all the changes here described have taken place within the last forty years—if a river of 
the power of the Genesee has in one place excavated a channel of these dimensions—what 
results may we not ascribe to similar action in larger bodies of water ? It is not too much to 
say that the deep gorge from Portage to Mount-Morris has been worn in the same way, or 
that the chasm of Niagara, from the falls to Lewiston, has been excavated by the stream now 
flowing in its bed. In making these estimates we are not to count time by years, but by 
ages ; and there is abundant testimony that years beyond our comprehension have passed 
since the surface of the earth assumed its present form, and since the rivers began to flow in 
their present courses. 
I have cited this case as an example, because it is one well known, and where observations 
have been repeatedly made ; and because, within the last five years, I have examined it seve¬ 
ral times, and each time with a conviction of the changes that were in progress. The break¬ 
ing up of the ice every spring removes large masses of rock at the head of this channel, and 
these, with others, are carried forward through the gorge, with a force that tears up its bed 
and sides. The table above, which was formerly the bed of the river, will, in a few years, 
become covered with soil and vegetation ; strong grass and willows have taken root in the 
fissures, and these collecting about them a little earth, giving a soil for the support of the 
other plants, the evidences of its original condition will be lost. A century hence some incredu¬ 
lous observer may stand on the edge of this table rock, then covered with shrubs and trees, 
and deny that the insignificant stream flowing in its bed can have excavated this deep chasm. 
An observer of similar dispositions may now stand upon the margin of the great gorge of the 
Genesee at Portage, and say that it is impossible for this river to have worn it to the depth of 
three hundred and fifty feet, and with a breadth of six hundred feet. But the Genesee was 
once a more powerful stream, and it has flowed in its present direction longer than we are 
usually accustomed to consider as the age of the world. 
The consideration of this small portion of the channel of the Genesee leads us to the exami¬ 
nation of the whole of that deep gorge extending from Portage to Mount-Morris. The greater 
portion of the channel for this distance, so different from that in which the river flows, either 
to the north or south, requires a different explanation of the mode of its formation. The river 
flowing northward from its source through the valley south of Portage, then bends around to the 
* For a knowledge of the early condition of this fall, and many of its successive changes, I am indebted to my friend Colonel 
Johnson of Hornby Lodge, who explored this part of the country in 1803. Col. Williams, an early settler in this region, gave 
me a very similar account of its condition when first known to him. 
47* 
