A UMNOLOGICAI. STUDY OF THE FINGER LAKES. 555 
length of time that the ice remained is not stated. Seneca Lake has the following 
record ; 
1855, closed February 24, opened March 15. 
1875, closed February 9-10, opened March 14. 
1885, closed February 24, opened March 6. 
1912, closed February ii, opened March 10. 
Partially closed: 1856, 1865, 1904. Skimmed over with thin ice in spring: May 7, 1829, 
May 4, 1856, May 5, 1861, May 15, 1872, May 6, 1873, April 26, 1884.“ We are not 
sure that this spring freezing extended over the entire expanse of the lake. 
The other lakes freeze regularly, though the central parts of deeper ones may 
remain open in mild winters. Freezing usually occurs in January or early February. 
Table iii gives the important facts for the winter observations made on these lakes. 
The surface temperature of the lakes which were frozen is that of the water which rose 
in a hole cut through the ice. The temperatures of the frozen lakes are no doubt subject 
to less error than are those taken in the open water and more closely represent the mean 
temperature of the water of the lake. But the lakes were visited during a rather warm 
and calm period, so there is no reason to believe that any are seriously wrong. 
The temperature of Owasco Lake seems very low in 1911, but table ix (p. 560) 
shows that the lake had lost the same amount of heat per unit of surface as Cayuga 
Lake. In the same table losses of heat in Seneca Lake seem to be low and those of 
Skaneateles Lake are high. Yet until we know the range of winter temperatures there 
is no reason to suspect serious error in either. In 1911 Skaneateles Lake was only 
partly frozen and the process of cooling was still going on. In 1912 the lakes all froze 
over early on account of the unusually severe winter and this fact would lead us to 
expect rather high temperatures for the water of the lakes observed at that time. 
Table IV. — Winter Temperatures. 
Lakes. 
Year. 
Condition. 
Temper- 
ature, 
surface. 
Temper- 
ature, 
bottom. 
1911 
1911 
1912 
1911 
1912 
1912 
Open 
** C. 
2. 00 
. 10 
.80 
3 - 25 
. 70 
I. 00 
°C. 
2 - 75 
1. 20 
2 . 25 
3 - 50 
® I. 20 
3 - 10 
Partly frozen . . 
“ 50 meters. 6 75 meters. 
MEAN SUMMER TEMPERATURE. 
From a series of temperatures taken in the deepest water of the lake, the mean 
temperature of the water of the lake may be computed. If the mean temperature of 
each stratum is multiplied by the per cent of that stratum in the total volume of the 
Data from Prof. E. H. Eaton, Hobart College, Geneva, N. Y. 
