LOCAL CLIMATOLOGY. 



101 



Month. 



Inches. 



Month. 



Inches. 



Month. 



Inches. 



January 



February 



March 



1.594 

 1.138 

 1.888 

 3.375 



May 



2.933 

 3.121 

 3.281 

 3.690 



September 



October 



November 



December 



2.499 

 3.122 

 2.254 

 2.027 







August 





It is indeed true that the equinoxes occur in March and September, 

 but the effects of the disturbance could hardly reach us short of a week 

 or ten days ; and the averages above given are made out for the calendar 

 months. But if we should make the average for the thirty days com- 

 mencing with the equinox, the result would not be materially different. 

 Naturally we have more precipitation of vapor in summer than in winter. 

 This is seen in the above statement. But we also see the fact that there 

 is an increase from March to April, being in the month after the equinox 

 nearly double what it was the month before ; and also the other fact that 

 there is more in October than in September, 3.122 against 2.499, not- 

 withstanding it occurs in the season when the amount is decreasing 

 towards its winter minimum. 



6. Finally, we notice in the spring, commencing May 25th, an arrest 

 of the increasing warmth, and in fact a retrocession for about sixteen 

 days mitil June 12th, and a similar arrest and retrocession of the increas- 

 ing cold in autumn, from October 28th until about the 10th of November. 

 It has been a matter of general observation that we have a frost in the 

 last of May or the first of June, and the " Indian summer," as it is called, 

 is an acknowledged '■'■institution" of our climate. But the figures and 

 diagram before us put these things into a more definite form than I have 

 ever seen them in before. The temperature increases quite regularly from 

 the time of the greatest cold in February up to the 24th of May, when 

 it reaches in the general average 63°.29, with a maximum for the day of 

 84°.5, and a minimum of 42°; and with about the same maximum and 

 minimum for the next day, it falls off in the general average to 60°. 84, 

 and does not reach 63°.29 again until June 12th, a period of eighteen 

 days. During this time it falls in the general average to 57°. 32 for May 

 28th ; it then rises to 62° and something over, for the last day of May 

 and the three first days of June, and then falls to 60° again for several 

 days; and the average for the whole eighteen days is 60°.60, or nearly 

 3° less than that for the day preceding this period or for those succeed- 

 ing it. 



