364 Wisconsin Academy of Sciences , Arts, and Letters. 
TABLE 10 
Thermal resistance of Lake Mendota for temperature condition used 
in preceding tables. 
Depth 
T 
1-D 
Depth 
D*-Di 
8 
0.. 
24.2° 
0.002727 
0-1 
15.4 
23.7 
2604 
1-2 
15.0 
2. 
23.2 
2483 
2-3 
12.1 
3. 
22.8 
2388 
3-4 
5.9 
4. 
22.6 
2341 
4-5 
3.0 
5. 
22.5 
2318 
5-6 
3.0 
6. 
22.4 
2295 
6-7 
3.0 
7. 
22.3 
2272 
7-8 
44.4 
8. 
20.7 
1917 
8-9 
36.7 
9. 
19.3 
1628 
9-10 
62.2 
10. 
16.6 
1130 
10-11 
24.4 
11. 
15.4 
935 
11-12 
11.4 
12. 
14.8 
844 
12-13 
7.4 
13. 
14.4 
785 
13-14 
5.2 
14. 
14.1 
743 
14-15 
5.2 
15. 
13.8 
701 
15-16 
3.1 
16. 
13.6 
674 
16-17 
1.6 
17. 
13.5 
661 
17-18 
5.0 
18... 
13.2 
621 
18-19 
1.5 
19.. 
13.1 
609 
19-20 
0.6 
20. 
13.1 
609 
20-21 
0.4 
21..... 
13.1 
609 
21-22 
0.3 
22. 
13.0 
596 
22-23 
0.2 
23. 
13.0 
596 
23-24 
0.1 
24. 
13,0 
596 
The numbers in the last column show the thermal re¬ 
sistance in each meter in terms of the unit stated on the pre¬ 
ceding page. The results are also shown in fig. 10. In this 
figure the values of the thermal resistance are platted in the 
middle of the space assigned to each meter. The diagram 
shows, even more clearly than the table, the strata of the 
lake where thermal resistance is greatest. These are the 
upper three meters, where there is a super-heated layer 
which will make it hard to get heat from the surface to the 
strata below. On the other hand, while the difference in 
density is considerable, the decline of temperature is not 
great, (pi. II) The loss of relatively few calories would 
permit the easy transfer of heat through the epilimnion 
from surface to thermocline. 
The situation at the thermocline is very different. Here is 
a sudden and great rise of resistance, so great that only very 
strong winds can force warmed water into the cooler strata, 
even those at the top of the thermocline. When therefore 
such a fully developed thermocline has appeared it offers a 
very effective resistance to the direct influence of the wind. 
