Trains of Boulders, in Berkshire, Mass. 391 
of several thousand feet, in a course of fifty miles, into the 
low, broad valley of the Hudson. Few persons are aware of 
the enormous speed which such a declivity would, of itself, 
impart to a deep and wide-spread stratum of water. The 
only currents we can actually observe are the confined and 
shallow ones of rivers, and of the tide in certain obstructed 
straits, and, in these, the velocity is kept down by the very 
trivial declivity of the channel, and by the disproportionate 
friction and resistance produced by the proximity of the shores 
and the bottom. Yet, notwithstanding this retardation, we 
may notice how rapidly the current of any river is accelerated 
when a freshet deepens its stream by only a few feet or 
fathoms. When the waters of the Ohio are swollen, they 
have a mean velocity of several miles an hour; yet the slope 
of its bed does not exceed eight or ten inches per mile. And 
the Gulf Stream, that stupendous river in the Atlantic, pos- 
Sesses, from the mere fact of its great depth and breadth, and . 
ils exemption from friction, a velocity of more than three 
miles an hour, although its actual descent is almost inappreci- 
able. How terrific, then, must have been the speed of a con- 
Unental inundation, unconfined by any shores, and deep enough 
to °vertop the summits of our highest mountains, and moving, 
In some portions of its progress, down the long-inclined planes 
of the surface, with a slope even more than fifty times as great 
as that of the most impetuous rivers. In the case before us, 
the Waters, hurrying thus along the Adirondack slope, would 
Sweep, unresisted, across the wide valley of the Hudson, and 
Tüsh, with incalculable violence, against the western crests of 
the Green Mountains and the Taconic chain. At a certain 
Stage, early in the dispersion of the flood, the ice, which, until 
“en, had rushed unchecked across the highest peaks and 
ridges, would, necessarily, subside to their level, and would, 
here and there, strike with a force which no imagination can 
Conceive, Standing on the Canaan Mountain, it is easy to see, 
as we look north-westward, towards the lower plain of the 
Hudson, and discern no barrier, in all that quarter, that could 
break the fury of the inundation, that this sharp and narrow 
