35^ Tlic American Gcolog Jmio, i><98 
of the ancient peneplain, stand but slightly above the sea level, 
while in Maine, New Hampshire, \'ermont and western 
Massachusetts, their elevation is 2,oco to 4,000 feet above the 
; sea. This average rise is taken as evidence that the peneplain 
j lias been uplifted, and that in the uplifting it has been so tilted 
\ that it slopes at about the rate here indicated. So far as I can 
find out this is an assumption rendered necessary to explain 
the difference in elevation of the supposed peneplain; but 1 
fail to find that there is any evidence to prove it, unless the 
peneplain be previously accepted as a condition covering this 
entire region. While near the coast there is a certain sem- 
blance of levelness, I am utterly unable to find even the ap- 
pearance of uniformity in the more elevated sections of New 
England. 
In addition to this general deviation from the level condi- 
tion of the supposed ancient peneplain, there are certain peaks 
which rise distinctly above the average level of the surround- 
ing crests which are supposed to be remnants of this pene- 
plain. Of this mount Monadnock, in southern New Hanip- 
/ shire, is selected as typical, and the members of this class of 
mills have been given the name monadnock by Prof. Davis. 
There are innumerable smaller monadnocks scattered about 
in New England; and some, like Mt. Katahdin in Maine, are 
even higher than the type. This class of irregularity is ex- 
f plained by a second assumption, — that they now rise above the 
general level, somewhat as they did before the peneplain was 
uplifted, because they were residuals that had not been low- 
ered to the peneplain level, probably either becaj^ise- of the 
greater durabilit y of their rocks^ or some other accidental 
reason, such as greater original elevation. In tliis case also 
I am unable to find that there is any other proof that this 
interpretation is correct than that which comes from the neces- 
sity of such an explanation, made necessary by first accepting 
the existence of the peneplain. 
Granting these two assumptions for the purpose of exam- 
ining the evidence of a peneplain, I have taken several of the 
sheets of Connecticut and New Jersey, disregarding the grad- 
ual north and south rise of the crests, as well as eliminating 
the hills that rise well above what might be considered the 
average crest line, and hence which might b" f-alled monad- 
