318 Exploring Visits to the Sources of the Hudsoi. 
to the whitened path of a slide which had recently descended into 
Avalanche Lake. In a direction a little south of west, the great ver- 
tical precipice of the Wallface Mountain at the Notch, distinctly met 
our view. Deeply below us on the northwest and north, lay the 
valley of the west branch of the Au Sable, skirted in the distance 
by the wooded plains which extend in the direction of Lake Placid 
and the Whiteface Mountain. 
Mount McIntyre is also intersected by dykes, which cross it at 
the lowest points of depression between its several peaks, and the 
more rapid erosion and displacement of these dykes has apparently 
produced the principal ravines in its sides. ‘The highest of these 
peaks on which we now stood, is intersected by cracks and fissures 
in various directions, apparently caused by earthquakes. Large 
blocks of the same labradoritic rock as the mass of the mountain, 
lay scattered in various positions about the summit, which afforded 
nearly the same growth of mosses and alpine plants as the higher 
peak visited on the 5th. Our barometric observations show a height 
of near five thousand two hundred feet, and this summit is proba- 
bly the second in this region, in point of elevation. ‘There are 
three other peaks lying in a westerly direction, and also three others 
lying eastward of the main source of the Hudson, which nearly ap- 
proach to, if they do not exceed, five thousand feet in elevation, 
making of this class, including Mount McMartin, Whiteface, and 
the two peaks visited, ten in all. Besides these mountains there 
are not less than a dozen or twenty others that appear to equal 
or exceed the highest elevation of the Catskill group. 
Visit to the Great Notch.—Return to the Settlement. 
The descent of the mountain is very abrupt on all sides, and our 
party took the rout of a steep ravine which leads into the valley of 
_the Au Sable, making our camp at night-fall near the foot of the 
mountain. The night was stormy, and the morning of the 9th 
_ opened upon us with a continued fall of rain, in which we resumed 
our march for the Notch, intending to return to the settlement by 
this rout. After following the bed of the ravine till it joined the 
Au Sable, we ascended the latter stream, and before noon arrived at 
this extraordinary pass, which has been described by the state geol- 
ogists, and which excites the admiration of every beholder. Vast 
blocks and fragments have in past ages fallen from the great preci- 
pice of the Wallface Mountain on the one hand, and from the south- 
