OF TEMPERATURE AT TORONTO IN CANADA. 
153 
true within the limits which are at present required for the comparison of the non- 
periodic variations in Europe and America. The observed temperatures themselves 
may be obtained, if they are required, by adding or subtracting (as the case may be) 
from the mean daily temperature in column 1, the difference which stands on the 
same horizontal line with the day, and in the same vertical line with the year. The 
final column (14) shows for each day the average non-periodic variation in twelve 
years. We may learn, consequently, from this column, the average non-periodic 
variation in twelve years of any particular day of the year which may be surmised 
to be subject to some special physical peculiarity, causing it to be warmer or colder 
than the general progression of the temperature in the part of the year to which it 
belongs. An example of its application may be given by the reply which the values 
in this column furnish to the question*, whether the three days of May (the 11th, 
12th, and 13th), which Madler has stated to be characterized, on the average of 
eighty-six years of observation at Berlin, by a depression exceeding 2° Fahr. when 
compared with the general march of the temperature at that season, undergo a 
similar depression in North America. On a reference to the month of May in 
Table IV., it is seen in column 14 that on the average of the twelve years from 
1841 to 1852, the 11th of May was 0°*1 helow, and on the 12th and 13th of May 
respectively 3 1 and 2 4 above the general mean of the temperature in those years. 
It may be seen also that the average non-periodic variation in the five days from the 
8th to the 12th of IVIay inclusive, is in the same twelve years I'^'l above, and in the 
five days from the 13th to the Ifth inclusive 1°'0 above, the general mean of the 
temperatuie. The meteorological observations at Toronto during these twelve years 
do not therefore support the supposition that the depression of temperature on the 
11th, 12th and 13th of May, observed at Berlin, is a general and periodically recur- 
ring phenomenon over the whole globe; such as would be occasioned by a partial 
obscuration of the sun’s disc by the intervention of a periodical stream of aerolites ; 
but they tend rather to indicate that the depression observed in Europe may have 
been a partial phenomenon, having a local cause. 
The not unfrequent occurrence of differences of large amount on single days, shown 
in columns 2 to 13, is an indication of the great variability of the climate of Toronto 
in regard to temperature ; and the still remaining occasional magnitude of the daily 
averages in column 14, shows that the influence of non-periodic variations is by no 
means extinguished in the means of twelve years. 
* Kosmos, Bd. i. S. 407. Anm. 56. 
