218 Wisconsin Academy of Sciences , Arts and Letters. 
although the surface temperatures in Pine Lake, in both July and 
August, are higher than in Green Lake, the temperature of the deep 
water is nearly the same. For instance, in August, 1879, at a depth of 
18.28 meters, the bottom temperature was 7.23° C., while the surface 
temperature at the same time was 24.44° C., and in July, at a depth of 
24.38 meters, the bottom temperature was 5.56° C., and the surface tem¬ 
perature 26.12° C. Thus, at 24.38 meters, was reached very nearly the 
minimum temperature which I found in Green Lake at 50 meters and 
below. 
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