M 
I 
2 
3 
* 
5 
6 
7 
e 
9 
10 
II 
12 
13 
J4 
15 
16 
II 
16 
19 
20 
21 
22 
23 
24 
Af. 
Birge—Work of Wind in Warming a Lake . 
373 
Plate I 
