202 Wisconsin Academy of Sciences, Arts, and Letters. 
ature of the lake, which would come at the time of freezing. 
Green lake seems to gain about 25 cal. per sq. cm. of surface 
per day during the ice-period. The temperature at the time 
of freezing might have been as much as 0.5° (1600 cal.) colder 
than the record in March. But there is no doubt that the lake 
might freeze at any of the temperatures indicated. 
No. 8. Lago di Bolsena.—The large I heat-budgets of this south¬ 
ern lake are noteworthy, especially in comparison with those of 
the lakes north I of the Alps. It will be observed that the low 
temperature record of 1900 can not be used as basis for a bud¬ 
get. It no doubt indicates a very small heat budget for that 
year. A longer series from Bolsena should show variations like 
those of Como and Geneva. 
No. 9. Lago cl’Orta.—No definite conclusion can be based on 
the single i budget from this lake, although it is probable that 
Como, like Geneva, has a larger budget than its smaller and 
shallower neighbors. 
No. 10. Lac du Bourget.—Very probably the temperature of 
March 4, 1894 is above the minimum for that year, and probably 
the temperature in Feb. 1895 was below the minimum of the 
preceding year. This is clearly the case in the neighboring lac 
d’Annecy. This lake and lac d’Annecy lie near the southwest¬ 
ern end of lake Geneva. They evidently are lakes (which are 
near the dividing line between Forel’s classes of tropical land 
temperate lakes. 
No. 11. Lac d ’Annecy.—This lake was measured from Dele- 
becque’s large map land its volume was computed from my 
measurements. The result for total volume was substantially 
the same as that given by Delebecque. The maximum I depth 
should be stated as 64.7 m. since this is the maximum depth in 
the central plain of the lake. The depth 81.6 m. is found in the 
Boubioz, a large sub-aqueous spring, but so small that it has 
no appreciable effect on the total volume of the Hake. From 
these measurements of volume, I have computed the tempera¬ 
ture. The result are higher for the years 1890 and 1891 than 
are those of Halbfass. They are substantially the same in 1893. 
No. 12. Lago di Como.—The mean temperatures given by 
Halbfass in his two papers differ considerably. I have used the 
later figures, since they have probably been revised and corrected. 
These changes throw some doubt Ion the temperature for the 
summer of 1898, which is given only in the paper of 11905, and 
