Birge—Heat Budgets of American and European Lakes. 197 
AND EUROPEAN LAKES—Continued. 
Winter Tempera¬ 
ture, Tm w - 
Summer Tempera¬ 
ture, Tm s - 
Tm 8 '- 
- Tm w 
Annual 
Heat 
Budget 
Wind-distributed 
Heat. 
Dm (Tm 3 -4-) 
Dm (Tm s . 
No. 
_Tm w > 
Date. 
Value 
Date. 
V alue. 
Year. 
Value. 
Calories. 
Year 
Calories. 
1890 II 2 
3.71 
| 1889 VIII 9 
9.79 
89-90 
6.08 
26,100 
89 
24,900 
18 
1891 III 6 
3.34 
| 1890 VIII 15 
9.15 
90-90 
5.44 
23,400 
90 
22,100 
1892 II 7 
3.45 
1891 VIII 25 
8.60 
91-91 
5.36 
23,000 
91 
19,800 
1893 TUI 
3.57 
| 1892 VIII 21 
9.58 
92-91 
6.24 
26,800 
92 
24,000 
1894 II 4 
3.49 
92—92 
6.13 
26,400 
. 
92-93 
6.01 
25,800 
| ■ 
Mean 
25,300 
Mean 
22,700 
1890 VIII 20 
6.48 
90 
21,300 
19 
1893 IX 6 
6.82 
93 
24,300 
1894 VIII 22 
6.75 
94 
23,600 
Mean 
23,000 
1849 II 2 
3.48 
1848 VI 9 
7.74 
48-49 
4.26 
27,700 
48 
24,300 
20 
1897 II23 
4.43 
1849 VIII 31 
7.80 
49-49 
4.32 
28,100 
49 
24,700 
1868 IX 26 
7.58 
96-97 
3.69 
24,000 
68 
23,300 
1869 IX 23 
7.25 
Mean 
26^600 
69 
21,100 
1891 VI11 28 
7.59 
91 
23,300 
1896 VIII 22 
8.12 
96 
26,800 
Mean 
237900 
1894 III 16 
3.30 
1881 IX12 
7.71 
93-94 
4.08 
1 
22,000 
81 
20,000 
21 
M3 IX 21 
7.37 
94-94 
4.74 
25,600 
93 
18,200 
1894 VIII 11 
8.03 
94 
21,800 
1895 IX 8 
*8.16 
95 
22,500 
1896 VIII 3 
7.28 
96 
17,900 
1897 VITT 21 
*8.32 
97 
23,300 
1900 VII 27 
*8.17 
00 
22,500 
Mean 
20,700 
1903 IX 28 
1 1 
*8.97 
J 03 
18,900 
22 
1881 IX13 
*9.14 ! 
1 
81 
19,500 
1875 IV11 
3.68 
1848 IX 2 
7.22 
74-75 
3.28 
27,600 
48 
27,000 
23 
1868 X 5 
7.12 
68 
26,200 
1870 IX 23 
6.09 
70 
17,600 
1873 X 6 
*6.83 
73 
23,800 
1874 IX 21 
*6.96 
74 
24,900 
1878 X 6 
*6.25 
78 
18,900 
1891 IX 18 
6.88 
91 
24,200 
1894 IX 26 
*7.42 
94 
28,700 
1895 VIII 31 
7.74 
95 
31,400 
Mean 
24,900 
