186 Wisconsin Academy of Sciences, Arts, and Letters. 
2. The small loss of heat below 4° in these lakes as compared 
with north European or American lakes. In the case of Mill- 
statter See and Ammer See, where no winter temperatures are 
recorded, this item is conjectural and is so indicated by the use 
of dotted lines. 
8. The uniformity oF the American lakes, both as to losses be¬ 
low 4° and gains above it. The diagram also brings out a pos¬ 
sible error in the observations on Seneca lake. We can give no 
reason why that lake, which does not freeze, should not have 
lost as many calories per sq. cm. in 1911 as the other lakes. 
Cayuga lake, which also does not usually freeze, shows substan¬ 
tially the same losses as Owasco and Skaneateles, whose temper¬ 
atures were taken through the ice. Yery likely, therefore, the 
water at the point of observation in Seneca lake showed a tem¬ 
perature somewhat above the mean of the lake. It is quite pos¬ 
sible, however, that the observation correctly shows the facts. 
4. The three northern lakes of the continent of Europe show 
a budget of similar character in'spite of great differences in area 
and depth. In each case there is a very large loss below 4°, so 
large as to affect the possible gains above 4°. The gains of 
Ladoga and Wettern seem to be closely similar, although more 
evidence is needed on this point, either to confirm or refute it. 
5. The very large and deep lakes, Mjosen, Ness, Geneva, and 
Como, have on the whole decidedly larger budgets than the lakes 
which are their neighbors. This inference is weakened by the 
small budget found for Thuner See in 1908-09, but this'may be 
due to local reasons, or a larger series of observations may show 
that its great mean depth—50% greater than any of its neigh¬ 
bors—gives it a certain advantage over them, when the average 
of a considerable number of series is taken. 
6. The large budgets of lago di Bolsena show (a the favor¬ 
ing effect of area on budget; (b) a high winter temperature 
is not incompatible with large gains of heat. 
7. The fact that the Scottish lakes are tropical in spite of 
their high latitude is a testimony to the general mildness of the 
winter. It is surprising that summer gains of heat are so large. 
Continuous sunshine, however, is by no means especially favor¬ 
able for large gains of heat, as it warms the surface too rapidly. 
