554 
BULLETIN OF THE BUREAU OF FISHERIES. 
direct observations to support the conclusion. In 1910 March and April were warm 
and May was unusually cold. The average of reports of the weather stations at Auburn, 
Geneva, Hemlock Take, and Ithaca, all of them in the Finger Take district, show that 
April, 1910, was 2.7° C. warmer and May 1.7° C. cooler than the average temperature 
for those months. In 1911 these conditions were exactly reversed; March and April 
were somewhat, but not greatly, colder than the average, and May of that year was 
exceptionally warm. The average of the four stations named shows for April a deficiency 
of 0.4° C. and for May an excess of 4.1° C. This excess was more noteworthy since the 
first five days of the month were much colder than the average for that period. 
The high temperatures of the hypolimnion and the bottom water in 1910 and their 
lower condition in 1911 were due to these differences in the weather. The exceptional 
heat of May, 1911, caused the surface water to warm so rapidly that it prevented the 
distribution of heat to the deeper water, while the earlier part of the season was so cool 
that the lakes had warmed but little when the warmer weather began. In 1910 the 
high temperatures of March and April came while the lakes were still below 4°, or close 
to that temperature, and the cool weather in May favored the distribution to deeper water 
of the heat acquired earlier or during that month. 
Owasco Take in 1912 had a bottom temperature slightly higher than in 1910, and that 
of Skaneateles Take was much above that of 1910 (see p. 565). No definite general 
features of the weather in spring can be assigned as the cause; and this is commonly 
the case, since bottom temperatures ordinarily depend on special events in the weather 
rather than on its general character. 
A word may be said regarding the temperature seiche as an agent for warming the 
hypolimnion. No observations have been made as yet which show that the temperature 
seiche has any noteworthy influence in this direction. The warming of the bottom 
water is effected chiefly in the early part of the season, before the thermocline is estab- 
lished, and while the differences in temperature between surface and bottom are slight. 
Under these conditions the direct effect of wind is great and that of the temperature 
seiche is nonexistent or feeble. When the epilimnion has been formed and the tempera- 
ture seiche can operate vigorously, the thermocline forms the zone of friction, or mixture, 
of the cooler and warmer water. Its mean descent is very slow, so far as observations 
have told the facts, after it gets far enough down to escape the ordinary direct influence 
of the wind, until it begins to sink again in consequence of the autumnal cooling of the 
lake. Thus it appears that but little work is done by the tenperature seiche in carrying 
the warm water downward, and this work, whether great or small, is mainly expended in 
extending the lower limits of the epilimnion and has little, if any, effect on the lower 
water. 
WINTER TEMPERATURES. 
Seneca and Cayuga Takes are rarely frozen over except at the ends, and to a small 
extent along the shores. Tocal records show that Cayuga Take was completely frozen 
in the following winters: 1796, 1816, 1818, 1836, 1856, 1875, 1884, 1904, 1912.“ The 
“ The Auk. vol. 29, 1912, p. 438. 
