Birge—Work of Wind in Warming a Lake . 
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THE WORK OF THE WIND IN WARMING 
A LAKE 
Edw. A. Birge 
Notes from the Laboratory of the Wisconsin Geological 
and Natural History Survey. VIII. 
1. INTRODUCTION. 
It is now generally admitted by limnologists that" the 
warming of a lake is mainly effected by the wind, which dis¬ 
tributes the warmed water from the surface to the deeper 
strata. Certain limitations on this statement due to the 
penetration of the sun’s rays into the water, will be briefly 
discussed later in this paper. This relation of wind to heating 
was well stated twenty years ago by Whipple (’95, p. 207). 
I worked out the same result in the same year but did not 
publish until 1897 (’97, p. 291). In the same paper I indi¬ 
cated also, I believe for the first time, certain corollaries 
from this theory of heat distribution, stating that the depth, 
area, and shape of a lake are important factors in determin¬ 
ing its temperature. 
Another corollary from the fundamental proposition 
engaged my attention, viz.: that the distribution of the 
warmed—and therefore lighter—surface water by the wind 
involves an amount of work against gravity which is meas¬ 
urable, and whose amount shows one element in the work of 
the wind on the lake. It affords also a quantitative measure, 
at least a partial one, of the effect of area and depth on the 
heat budget. This idea was applied to the explanation 
certain temperature phenomena in my discussion of the 
Finger Lakes of New York in 1914 (Birge and Juday, 
