270 Scientific Intelligence. 
ing, until, in 1859, it amounted to about 82 days. A glance at-these re 
sults at once suggested the idea that the variable period thus found was 
in some way connected with, and dependent upon, the great solar-spot 
period, the minimum value occurring in the year of minimum frequency 
. of the solar spots, and the maximum values in the years when the spots 
were most numerous, 
Several series of thermometrical observations were now examined for 
only 11°79° of plus differences, the mean ratio of the amount of excep 
tional differences to the total amount being therefore as 1 to 25°7. 
a At Petersburg the average temperature of the warmer half of the 
_Period is not less than 3° greater than that of the cooler half; and as this 
of temperature is repeated at least twelve times in every Ye" 
SEER Ree Fo ere Sara ee eS ay tS ee ee 
