172 
During the months of January and February there is a 
period of minimum temperature approaching 32°, averaging 
32.75°, and rarely exceeding 34°. The constancy of the tem- 
perature at this season is probably due in large part to the 
equalizing effect of the ice which normally covers the stream, 
and especially its backwaters, at this season of the year. Dur- 
ing the early part of March the temperature rises, but the rate 
becomes more rapid in the last part of the month. The up- 
ward movement reaches 40° or 50°, in early springs, such as 
1898, attaining the latter temperature. The average for the 
month rises to 40.45° and the fluctuations increase in extent. 
The rapid rise continues through April, attaining 60°—70°, and 
averaging 60.46°. The records for this month are somewhat 
meager for any comparisons. In May the season of maximum 
temperature is approached and occasionally reached, as in 1896, 
the average temperature from somewhat scanty records being 
then 68.27°. This month is one not only of marked rise but 
also of considerable fluctuation. The period of maximum tem- 
perature is in full swing in June, and continues through July 
and August and well over into September. The average rises 
from 77.75° in June to 81.49° in August, and falls to 74.21° in 
September owing to the decline which begins in the latter part 
of this month. This period of maximum summer heat is fairly 
well defined in the thermograph and continues at or near 80° 
approximately three months, from the middle of June to the 
middle or latter part of September. It is a time of consider- 
able fluctuation, most of the movements being within 10°, 
though the range for August in the five years of record was 
from 74.3° to 89°. These fluctuations combined with the di- 
urnal changes and the wind are effective in producing a con- 
siderable vertical circulation of the water. 
Following the summer maximum comes the fall decline, 
which begins late in September and is practically completed 
in November. The greater part of the change takes place in 
October, the average decline in that month being 16.76°, while 
that in November is 14.55°. In some years, as 1897, the de- 
