104 RECORD OF AURORAL PHENOMENA. 



illumined that part of the sky behind the cloud, gave it very much the appearance of an immense 

 explosion. 

 It is probable that this remarkable cloud had some connection with the Aurora Borealis; for after 

 it had vanished, which took place about six o'clock, that phenomenon was seen in the same part 

 of the heavens that the cloud occupied. It made its appearance, indeed, before the cloud dis- 

 appeared entirely, but not before it had lost its radiated form, and dispersed so much that nothing 

 particular could be seen about it." — Ibid., pp. 156-57. 



N. B. — 1. Between three and four p. m. remarkable cloud. 



2. It is probable that this remarkable cloud had some connection with the Aurora Borealis. 



Wellington Channel.— [Lat, 74° 54' N. Long. 93° W.] October, 1850. Kane. 



" 17th. A faint Aurora to the southward (true) at one a. m. 

 21st. A faint Aurora 8° east of magnetic north. 

 22d. A faint Aurora, more bright, with segment. 

 26th. Yery faint Aurora. 



27th. Bistre-colored auroral segment, 20° east of magnetic axis. 

 29th. Faint nebulous Aurora. 

 31st. Observed a small Aurora to the northward (by compass) at one a. m." — 1 Kane, p. 519. 



Baffin's Bay.— Lat. 75° 12' N. July 21, 1817. O'Reilly. 



"July 21, 1817. Thermometer 34°, 48°, 42°. Wind, a perfect calm. 



At three a. m. this morning, a most magnificent display of radiation occurred, of which a sketch 

 has been attempted. 



The cirrus radiation here remarked is always observed to issue from a body of detached clouds 

 assuming the form of an arch. Whether this curved arrangement be actually in a portion of a 

 circumference of a circle, or merely an optical delusion, I will not undertake to assert, but the 

 curve invariably appeared to me arched as I have related. The basis arch of the phenomenon 

 which occurred this morning was of amazing span, embracing several leagues of sea, the 

 central radius passing through the horizon in nearly E. by N. per compass; which corresponds 

 closely with the point of variation. 



The radiation darted rapidly and irregularly towards the opposite point of the sky in pale white 

 spires. The atmosphere in the southern region immediately became suffused with whitish-brown 

 cirro-stratus. Soon afterwards, various beautiful changes to minute cirro-cumulus and comoid 

 cirrus were observable. 



Within the arch lay a long linear bed of cirro-stratus, almost black, which preserved a horizontal 

 position and unaltered form during the radiation and the changes mentioned. In the space of 

 three hours from the first appearance, the whole was dissolved and dissipated, leaving the atmo- 

 sphere free of visible cloud, but not quite clear, being of a milky blue. 



I should not have intruded upon the reader's notice the detail of this radiation, had I not been 

 convinced, by repeated observations, that there exists a close, it may be said a direct, corre- 

 spondence between its appearance and the variation of the needle. From what cause this 

 singular coincidence proceeds, it will still longer, I fear, remain to be explored. The facts, 

 however, which are herein exhibited, may be relied on for the accuracy and faithfulness of report, 

 and may induce some enlightened and able mind to study a satisfactory illustration of the 

 phenomenon. 



It is right, also, to inform the reader that, during the formation and continuance of the radiation, 

 no irregular motion of the compass was observable ; the entire process appearing to go on at an 

 elevation far too great to admit of any influence on the needle. 



The state of the cloud, its being invariably a base of distinct cirro-stratus in a curved chain, the 



