Perry.] 108 a 28, 
on the melting of the ice during the newer Glacial period, it would 
be left in a jumble,—perhaps very nearly in the state in which we 
now find it, We should expect it to cover the whole surface, over- 
lying the hills, spreading across the valleys, and filling the old gorges 
and river-beds substantially as is known to be the case. Consisting 
of a strange medley of heterogeneous, unarranged material, it would 
appear, as it now lies in its undisturbed portions, in some places in 
greater, in others in less thickness. So we might expect to discover 
in it, sometimes far-travelled matter, sometimes not, accordingly as 
the portion of the ice-mass which transported it was favorably sit- 
uated for movement or the reverse. Parts of the same heap must 
likewise have come from afar, and portions from the neighborhood 
in which they are found. And while we cannot readily conceive the 
production of such a result, all over the country, in high places and 
low, by the action of icebergs, we see that the drift material is in just 
the plight it would have been likely to assume, it case it took its 
position in connection with the agency of a vast sheet of ice. 
These several points as connected with the overlying matter 
known as typical drift, that have been just passed in review, are 
facts which the iceberg theory cannot. explain as a whole, or in any- 
wise render consistently intelligible in their details. They are seen, 
however, so far as I can discover, to be perfectly natural, on the sup- 
position that an immense ice-sheet once covered the land for a long 
period. In the light thus brought to bear, the various facts appear 
to be perfectly explicable, and they all seem to point in the single 
direction indicated. While, thus, the hypothesis that a vast sheet of 
ice spread over New England, during the drift period, is becoming 
more and more probable, there are many attendant circumstances 
which appear to indicate that the work was only effected during a 
long lapse of time. 
§ 15. The Action of the Ice-sheet, 
(3). As attested by incidental phenomena. The facts now referred 
to, no less than those of the two classes just noticed, may bear testi- 
mony as to the length of the Glacial period, and the mode in which 
its work was accomplished. The phenomena in question, though 
they be not equally prevalent in all parts of the country, are suffi- 
ciently abundant in localities which were manifestly favorable to 
their production. They may be regarded as occasional concomitants, 
for they are not unfailing results, of glacier-agency. Properly looked 
