REPORT ON METEOROLOGY. 
257 
vations as were published * * * § . In support of his views he quotes 
the observations of Parry and Foster, particularly on the occa¬ 
sion of the luminous beam to which we have just alluded, which 
appeared to exercise no energy on the needle. Unaccount¬ 
able, however, as the discrepancy may be between travellers 
so well qualified to judge, and under such favourable circum¬ 
stances, Capt. Franklin and Dr. Richardson detected the most 
decided proofs of magnetic action of the aurora f. It must be 
obvious therefore, that independent of the difficulties of the 
observation, and the delicacy of the instruments required, 
there must be some innate source of difficulty in the subject. 
Mr. Farquharson has endeavoured to point out some expla¬ 
nation of these anomalies in a recent memoir in the Philoso¬ 
phical Transactions { ; where he states that from his observa¬ 
tions on the variations of magnetic intensity with auroral pheno¬ 
mena, and also of the dip and variation of the needle, he has 
found the effect to be a maximum when the streamers reach the 
plane of the dip, or when they pass through that region of the 
heavens to which the south pole of the dipping-needle points. 
Dr. Richardson had remarked that the effect on the needle was 
greatest when the streamers passed to the south of the zenith. 
This observation of Mr. Farquharson must therefore be con¬ 
sidered one of importance, though it does not quite explain 
some anomalies in the circumstances of the observations, espe¬ 
cially of those not made in high latitudes. As far as the 
observations of Mr. Farquharson himself go, they confirm the 
results obtained on the Continent ||. 
In almost every part of the continents bordering on the arctic 
circle have observations to the same effect been recently made. 
Prof. Kupffer has observed the influence of the aurora in the 
most striking manner at St. Petersburg, Nicolajew, and Kasan ; 
and the results of contemporary observations at these points 
are well worth consultations §. Prof. Hansteen has detected the 
same at Tornea in Lapland ^f, and M. Riess of Berlin has lately 
observed with care the influence of the aurora upon the mag- 
* Edinburgh Journal of Science, viii. 189. 
f See Franklin’s Second Journey; the Edinb. Neiv Phil. Journal ; and the 
Bulletin des Sciences Mathematiques , xi. 293. These observations have given 
rise to some criticisms by Dr. Brewster, which have been replied to by Mr. 
Christie in the Journal of the Royal Institution. 
J For 1830, p. 97. 
|| For an abstract of Mr. Farquharson’s paper, see the Edinb. New Phil. 
Journal, vi. 392; and the Encyclopedia Britannica, (New Edit.) art. Aurora 
Borealis. 
§ PoggendorfF’s Annalen, 1831. 
II Ibid. 1827; and Bulletin des Sci. Math. ix. 252. 
R 
