358 APPENDIX: 
So that this cannot be owing to the finking 
of the Snow to the Bottom of the River. 
5. Now fincc this freezing at the Bottom 
is never obferved, in Ponds and perfeftly 
Iragnating Waters, it muft therefore be ow- 
ing to the Motion of the Stream ; for in 
ftagnant Waters, as well as on the Earth, it 
is certainly colder in frofty Weather at their 
Surfaces than at fome Depth 5 whereas in a 
flowing Stream, the upper and lower Waters 
being continually blended together, they are 
thereby brought nearly to an equal Degree of 
Coldnefs, and the upper Water being at the 
fame time in a greater Degree of Motion 
than the lower, it cannot fo foon freeze ; for 
in this Bay, where the Motion of the Water 
was final!, its Surface was frozen over, as 
well as the Bottom, though not with fo 
thick an Ice: Whereas in the main River 
where its Motion was greater, its Surface was 
not frozen over, notwithfianding it was 
much overfpread with Ice-Meers, which 
were continually rifing from the Bottom. 
6. Another Caufe which may contribute 
to a River’s freezing firft at the Bottom, 
may be this, 'viZi. That as by Experience it 
\s found much colder to Hand expofed to a 
* * bleak 
