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by the expansive power of freezing Water. 143 
motion had been produced by repeatedly overturning the 
rocks, they would not have left channels behind them. 
And again, an immense force must have been exerted to 
remove these rocks, especially when we consider that one 
of them weighed by estimation 40 or 50 tons, and when 
we add to the resistance arising from its weight, that which 
must have been caused by the formation of a deep chan- 
nel after it. The expansive power of ice is a force abun- 
dantly sufficient. 
The view here given will explain another fact, which I 
have often observed, and for whic could never form a 
3 feet, when suddenly the bottom was covered with stones 
as far as I could reach it, in size and other respects 
resembling those with which the shore was lined. The 
case seems to have been this; the ice had gradually car- 
ried the stones on the bottom, as faras it could reach them 
by its thickness, to the shore, and had there deposited 
them. The hardness of the bottom had prevented deep 
chanuels from being made behind them, or they had been 
gradually filled up. 
If this explanation should be deemed unsatisfactory, it 
may, perhaps, at least, serve the purpose of leading others 
to give their attention to the subject, who may be more 
fortunate in their inquiries, and who have had greater op- 
portunities of observation. The cause to which I have 
ascribed these singular effects, viz. the expansion of the 
ice from the middle towards the borders, certainly exists, 
and is adequate to produce the effects in question. 
ith great respect, I remain, dear sir, your friend and 
very obedient servant, 
J. ADAMS, 
Sullivan’s Island, §. C., Aug. 9th, 1824. 
