1894. | NEW YORK ACADEMY OF SCIENCES. 19 
Professor Shaler designates the hills of contorted clays, sands 
and gravels upon which the moraine rests. It would imply a 
very great stress, suddenly and violently discharged, almost in 
the nature of an eruption in fact, and not a gradual mountain- 
making process, and so far as my experience goes, the facts do 
not warrant us in assuming that any such conditions have pre-. 
vailed. 
Finally any such development of force would result in the 
disturbance of strata far below the surface as well as above, and 
this we do not find to be the case. At Cold Spring, the super- 
ficial strata are beautifully crumpled, but where the lower strata 
are exposed these are seen to be undisturbed. This is the only 
locality in which I have been able to note this interesting and 
significant fact, but there is no doubt that if excavations below 
the limit of ice action were made at other localities, similar 
conditions would be found to exist. . 
In consideration of these circumstances it would seem as if 
any other reasonable theory than that of mountain-making 
forces, to account for the phenomena observed, ought to be wel- 
comed, and the theory of ice action, in connection with the con- 
tinental glacier of the Ice Age, has seemed to the writer to be an 
adequate and rational one. The facts are in harmony with it; 
it enables us to consider the entire area of disturbance as a 
comprehensive whole, with one series of cause and effect through- 
out, and not as a number of isolated districts in which similar 
phenomena are to be accounted for on different hypotheses. It 
is also a theory which nothing in our previous observation or 
experience would cause us to doubt, and is one which has been 
extensively applied to what are apparently identical phenomena. 
in Europe, especially on the islands of Moén* and Rugen,} in 
Denmark. 
I have elsewheref called attention to the fact that observers 
who visited Martha’s Vineyard in 1786 promptly ascribed a 
voleanic origin to Gay Head,§ and it is of interest to note, as 
* Jas. Geekie, ‘‘ Prehistoric Europe. 
Vide p. 200: ‘‘ Here and there irregular-shaped masses of bowlder-clay are actually 
surrounded on all sides by chalk, and:so striking indeed is the behaviour of the bowl- 
der-clay that Forchhammer may well be pardoned for having speculated upon its 
eruptive origin. Puggard was of opinion that all this confusion was due to movements 
of the earth’s crust, to convulsions and ‘“‘ faults’’ caused by the action of the subterra- 
nean forces, and in this view he was followed by Lyell:- But Johnstrup has since rein- 
vestigated the evidence and come to quite a different conclusion. He shows * * * that 
the disturbances can only be attributed to the enormous pressure and disrupting force 
of the Scandinavian mer de glace.” 
+ Rudolph Credner, ‘‘ Riigen. Eine Inselstudie,”’ Forsch. z. Deutsch. Land. u. Volks- 
kunde, vii. No. 5 (1893). 
t‘‘ Observations on the Geology and Botany of Martha’s Vineyard,” J. ¢., 9-12. 
ZSamuel West and William Baylies, Mem. Am. Acad. Arts and Sci. ii., part i., 147-150 
(1793), and 150-155 (1797.) 
