ESSEX COUNTY. 
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truth of this question, the character of the rock does not seem to be of any importance : for 
aught we know, this species of rock may enter into the formation of mountains of all ages, as 
well as any primary mass. This conclusion, however, is the one to which I have arrived, 
independent of the direction of its range, viz. that it is newer than the mountains of New- 
England. I have the Hoosic and Green mountain ranges in view in this comparison. It is 
true that the latter has suffered a movement since the deposition of the new redsandstone ; 
still, when the mountains of New-York are taken in connection with the tertiary of Lake 
Champlain, we must regard the latest movements of elevation to have occurred at a very 
modern period. But to determine when those movements commenced, is a difficult matter. 
We know that the Hudson river series is disturbed along the eastern base, or northeastern 
termination of some of those ranges ; an event which may have happened very soon after their 
deposition, or at a still later period.* More than one mountain range may have been elevated 
in the same era. Admitting that these elevatory movements are paroxysmal in a given direc¬ 
tion, it is very possible that during a period of quiescence, or between two paroxysms, an 
elevatory movement may occur in another direction, and alternate states of movement and 
repose may be the true condition of a continent. It may turn out, however, that the forces 
may be more active, or remain longer quiescent, in one system than in another. I conceive, 
from all the facts which bear upon this subject, that however certain it may be found that 
elevatory movements may have taken place since the deposition of a certain mass which is 
disturbed, still we shall not be able to show, even relatively, when the earliest movements 
were imparted ; for an upward movement may be slight, and not affect the masses of sediment 
accumulating around or at the base of a chain; it may take a much longer period to achieve 
a given elevation ; and during repose, or the moderate action of the forces, a range in another 
direction may be formed. But however this may be, there appears to be one point established, 
namely, that the forces which uplift mountain ranges act in certain directions in preference 
to others. 
To return for a moment to the shape of the mountains of hypersthene rock : I found them, 
as has been remarked, with conical summits ; each main summit presents generally three 
peaks, the highest of which is nearly central, or there is found a shouldered mountain. This 
form is so extremely rare in the Hoosic range, that I do not remember to have seen a good 
example of it, yet it is the principal form where the hypersthene rock composes the mountain. 
In these remarks, I may be in error in attributing the form or contour of the mountain to 
the kind of rock of which it is composed ; but I believe that none but an unstratified rock can 
produce precisely such forms as we find in the Adirondack group ; and I attach some impor¬ 
tance to the remarks, from the application we may sometimes make of them in forming our 
opinion of a mountain in the distance, whether a stratified rock forms its summit or not. Cer¬ 
tainly none of the mountains of gneiss, and they surround the Adirondacks on all sides, ever 
assume the form which these uniformly present; and I believe it may be told at a distance, 
whether a given mountain is composed of gneiss or hypersthene, by the shape of its summit. 
There is one feature in which the Adirondacks differ from the White mountains : it consists 
in the amount of boulders which cover the sides of the latter; for from what I learn from 
