THE TWO ORE A T SCULP TORS. 1 1 1 
very slowly and gradually water cuts its way ; for if 
a foot a year is about the average of the waste of the 
rock, it will have taken more than thirty-five thousand 
years for that channel of seven miles to be madei 
But even this chasm cut by the falls of Niagara is 
nothing compared with the canons of Colorado. Canon 
is a Spanish word for a rocky gorge, and these gorges 
are indeed so grand, that if we had not seen in other 
places what water can do, we should never have been 
able to believe that it could have cut out these gigantic 
chasms. For more than three hundred miles the River 
Colorado, coming down from the Rocky Mountains, 
has eaten its Way through a country made of granite 
and hard beds of limestone and sandstone, and it has 
cut down straight through these rocks, leaving walls 
from half-a-mile to a mile high, standing straight up 
from it. The cliffs of the Great Canon, as it,is called, 
stretch up for more than a mile above the river 
which flows in the gorge below ! Fancy yourselves 
for a moment in a boat on this river, as shown in 
Figure 27, and looking up at these gigantic walls of 
rock towering above you. Even half-way up them, 
a man, if he could get there, would be so small you 
could not see him without a telescope ; while the 
opening at the top between the two walls would seem 
so narrow at such an immense distance that the sky 
above would have the appearance of nothing more 
than a narrow rtreak of blue. Yet these huge chasms 
have not been made by any violent breaking apart 
of the rocks or convulsion of an earthquake. No, 
they have been gradually, silently, and steadily cut 
through by the river which now glides quietly in the 
