Mr . T. A. Knight on ice found in the bottoms of rivers . 287 
state of firm compact ice. The river was not, at this time, 
frozen over in any part ; but the temperature of the water 
was obviously at the freezing point, for small pieces of ice 
had every where formed upon it in its more stagnant parts 
near the shores; and upon a mill pond, just above the shal- 
low strea ms, (in the bottom of which I had observed the ice,) 
I noticed millions of little frozen spicula floating upon the 
water. At the end of this mill pond, the water fell over a 
low weir, and entered a narrow channel, where its course was 
obstructed by points of rock and large stones. By these, 
numerous eddies and gyrations were occasioned, which appa- 
rently drew the floating spicula under water ; and I found the 
frozen matter to accumulate much more abundantly upon such 
parts of the stones as stood opposed to the current, where 
that was not very rapid, below the little falls, or very rapid 
parts of the river. I have reason to believe, that it would 
have accumulated in very large quantities, if the weather had 
continued sufficiently cold ; for I had previously heard, from 
persons of respectable character, who had no interest, nor, I 
believe, intention, to deceive me, that, during a long and 
severe frost, some years ago, before I became an inhabitant 
of my present house, the whole bed of the river, in the part 
above-mentioned, had been covered over with a thick coat of 
ice. But it was not till the month of February that I wit- 
nessed the apparent deposition of ice in the manner which I 
have described ; and as the day afterwards became bright, 
the spicula soon ceased to form, and the ice to accumulate ; 
and before the middle of the day the greater part of it had 
disappeared. 
Upon some large stones, near the shore, of which parts 
