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XVII. On ice found in the bottoms of rivers. By T. A. Knight, 
Esq. F. R. S. In a letter addressed to the Right Hon. Sir 
Joseph Banks , Bart. G. C. B. P,R. S. 
Read May 23, 1816. 
Dear Sir, 
Accounts of ice having been found in the bottoms of rivers, 
have been so numerous, that the existence of it, in such situ- 
ations, has ceased to be questioned, though no satisfactory 
hypothesis, relative to the manner in which it can be formed 
in, or conveyed to, such situations has, I believe, ever been 
offered. Indeed its existence in such situations does not appear 
to be a common occurrence, and possibly it has never been 
seen, during its progressive formation, by any person likely 
to trouble himself about the causes of its existence. I there- 
fore take the liberty to submit the following account to your 
consideration. 
I first witnessed the existence of ice in the bottom of the 
water in the river Teme, which passes near my residence in 
Herefordshire, in the last winter. In a morning which suc- 
ceeded an intensely cold night, the stones in the rocky bed of 
the river, appeared to be covered over with frozen matter, 
which reflected a kind of silvery whiteness, and which, upon 
examination, I found to consist of numerous frozen spicula 
crossing each other in every direction, as in snow ; but not 
having any where, except very near the shore, assumed the 
