Chase.] 3^2 [February. 



the sun's distni'bing action on the equatorial portions of the 

 magnetic meridians is greatest during the liottest part, and 

 least in the coolest part of the day, while the moon's has two 

 nearl}^ equal maxima, about the times of its upper and lower 

 culminations, and two minima, near the times of its rising and 

 setting. 



Although the deductions which I have thus brought together 

 may contain little that is absolute^ new, they have the advan- 

 tage of a more general basis and a more compact presentation 

 'than those which are usually given in the discussions of local 

 observations, and any legitimate inferences to which they may 

 jointly lead, will, therefore, be entitled to more than ordinary 

 consideration. To my own view, it seems that a very cursory 

 examination of their bearings would justify the conclusions to 

 which I have been hitherto led by more special study (ante, vol. 

 ix, pp. 856-360, 36t-3tl, 427-440 ; x, 97-104, 151-166); but 

 for fear of an undue bias from the natural and unconscious 

 leaning of prejudice towards arguments which favor a precon- 

 ceived theory, I propose to follow, as impartiall}^ as may be, 

 Faraday's clue of the "lines of force." 



In the first column of the above synopsis of general means 

 there is a remarkable consistency, except in the mean of June 

 and July, which corresponds almost precisely with that of April 

 and September. The anomaly is perhaps owing to the pre- 

 dominance of the solstitial influence in June and July, of the 

 combined northern thermal and reactionary influences in Au- 

 gust, and of the N. autumnal equinoctial influence in September. 

 In the subsequent four and six months' groupings the aphelion 

 excess is very clearly shown. 



In the groupings wdiich are based on the distance of the 

 earth from the sun (III, IV, VI), and upon the semi-annual 

 thermal means (VIII), there is a uniform opposition between 

 the march of the numbers in the first and that in the second 

 column, increase of barometric pressure corresponding to de- 

 crease of declination disturbance, and vice versa. But in the 

 groups which are specially affected by equinoctial or solstitial 

 influence (I, II, V, VII), this uniformity is broken, and in one 

 instance (II) the contrariety is even changed into an agreement. 

 In each of these discrepant cases it will be seen that the mag- 

 netic basis is much broader than the barometric, which is 

 limited by the insular climate of Europe, and that the anomaly 



