114 ABNORMAL VARIATIONS AT TORONTO. 



reckoned from 2 p.m. to 2 p.m. is 7°.4, and the least 4°. 7. The 

 quarterly averages bein^ 5^.7 for spring, 5°. 2 for summer, 5°. 2 for 

 autumn, and 7°.2 for winter. 



In table VI. no distinction is made between the increasing and the 

 decreasing changes of temperature, and it does not appear whether the 

 changes of one sign are numerous and of small magnitude and those 

 of the opposite sign few and abrupt, or whether the changes in either 

 direction are on the average equal in number and magnitude. These 

 questions have been examined in the case of the differences betweem 

 2 P.M. and 2 p.m. in the years 1854 to 1859, and the following are 

 some of the results. 



It appears that in eight months of the year there is a preponderance 

 in the number of increasing changes of temperature, that throughout 

 the year the temperature rises 54 times out of 100 days, and that the 

 average value of an increasing change is .^'^.4, and of a decreasing 

 change 6'^. 3 nearly. The number of times out of a hundred days 

 that the temperature rises and the average increase and decrease in the 

 four seasons are as follows : — 



Number of increasing Average Average 



changes in a liundred. Increase. Decrease- 



Spring 55 5^.2 6°.4 



Summer 55 4°.7 5°.9 



Autumn 54 4°.9 5°.6 



Winter 51 7^.0 7^5 



Hence the descending changes of temperature are systematically- 

 more sudden at all seasons than the ascending changes. 



In table VII. the annual mean changes of temperature between 

 6 A.M. and 6 a.m. on consecutive days, are given with their proper 

 signs in eight groups corresponding to the resultant direction of the 

 wind during the day in which the change took place. From the more 

 complete tables from which table VII. is derived, it is found in the 

 earlier series, that in every month with a resultant wind from N , N. W., 

 and W. the temperature is lowered ; in every month with a resultant 

 wind from S.W., S., S.E., and E. the temperature is raised, and that 

 with a resultant wind from N.E. the temperature is raised in some 

 months and lowered in others, the collective effect in the whole year 

 being a rise of temperature with a N.E. wind. In the series, 1860 to 

 1862, the temperature is also lowered in all months with resultant winds 

 f m N., N.W., and W. ; but with winds from other points, although 



