388 Analyses of Books. [May, 



other circumstances, compels us to postpone, for the present, 

 the regular analysis of it which we purpose to give ; and to con- 

 tent ourselves with extracting from the copious Appendix, the 

 following observations on the Aurora Borealis, to which subject 

 Capt. Franklin's attention was expressly directed in his Instruc- 

 tions. 



Aurora Borealis. 



" General Remarks. — So few observations of the Aurora 

 Borealis in high northern latitudes have been recorded, that I 

 trust a minute account of the various appearances it exhibits, 

 will not be thought superfluous or uninteresting. The remarks 

 of the late Lieut. Hood are copied verbatim from his journal. 

 They speak sufficiently for themselves, to render any eulogiuin 

 of mine unnecessary. To this excellent and lamented young 

 officer, the merit is due of having been, I believe, the first who 

 ascertained by his observations at Basquiau-Hill (combined with 

 those of Dr. Richardson at Cumberland House), that the altitude 

 of the Aurora upon these occasions was far inferior to that 

 which had been assigned to it by any former observer. He also, 

 by a skilful adaptation of a vernier to the graduated circle of a 

 Kater's compass, enabled himself to read off small deviations of 

 the needle, and was the first who satisfactorily proved, by his 

 observations at Cumberland House, the important fact of the 

 action of the Aurora upon the compass-needle. By his inge- 

 nious electrometer invented at Fort Enterprise, he seems also 

 to have proved the Aurora to be an electrical phenomenon, or at 

 least that it induces a certain unusual state of electricity in the 

 atmosphere." 



" The observations of Dr. Richardson, independent of their 

 merit in other respects, point peculiarly to the Aurora being 

 formed at no great elevation, and that it is dependent upon cer- 

 tain other atmospheric phenomena, such as the formation of one 

 or other of the various modifications of cirro-stratus." 



" With respect to my own observations, they were principally 

 directed to the effects of the Aurora upon the magnetic needle, 

 and the connexion of the amount, Sec. of this effect, with the 

 position and appearance of the Aurora. I have been anxious to 

 confine myself to a mere detail of facts, without venturing upon 

 any theory. My notes upon the appearances of the Aurora 

 coincide with those of Dr. Richardson, in proving, that that 

 phenomenon is frequently seated within the region of the clouds, 

 and that it is dependent, in some degree, upon the cloudy state 

 of the atmosphere." 



"The manner in which the needle was affected by the Aurora 

 will need some description. The motion communicated to it 

 was neither sudden nor vibratory. Sometimes it was simulta- 

 neous with the formation of arches, prolongation of beams, or 

 certain other changes of form, or of activity of the Aurora ; but 



