401 [Chase. 
ology. The tendency to increase of auroras in clearing weather, and 
diminution in falling weather, is shown in the Auroral and Pluvial 
General Means : 
AURORAS. RAINFALL. 
Ho Be —— 5 
aa an 
Jan. 89 96 107 
Feb. 100 107 125 
March, 112 112 136 
Aprile 10g, 103 116 
May, 90 86 73 
June, 84 rage 42 
July, 92 85 45 
AUG 10) 103 7) 
Sept. 120 118 1 
1 
Oct. 118 17 13 
Nov. 96 103 121 
Dec. 81 93 1 
INFLUENCE OF METEORIC SHOWERS ON AURORAS. 
3y Pror. Puiny EARLE CHASE. 
(Read before the American Philosophical Society, May 16th, 1872.) 
Professor Lovering’s discussion of the periodicity of the Aurora Borealis 
(Trans. A. A. 8. V0. X., Part I.), not only exhibits maxima and minima 
of frequency at periods corresponding to general minima and maxima of 
rainfall (see above), but it also furnishes evidence of a tendency, in other 
great atmospheric disturbances, to increase auroral displays. 
In preparing the following table, I first took the second means of 
Lovering’s Table LIT. (containing 10816 auroras, arranged according to 
their frequency on each day of the year). After grouping the results in 
five-day periods, I calculated the ratio of each ordinate to a mean ordinate 
of 100. Against each ordinate which corresponds to a supposed meteoric 
period, I set the initial K. (Kirkwood’s ‘‘ Meteoric Astronomy’’), or W. 
(Wolf, cited by Lovering, p. 221). 
A. P. 8.—VOL. XII.—2Y 
