A NORTH-WEST PASSAGE. 199 



numbers, for the purpose of rearing their young. As the 

 care of the parent bird is so great, that it will divest itself 

 of its own soft covering to guard its young against the 

 inclemency of the climate, the nest may, to such as seek 



here remarked is always observed to issue from a body of detached 

 clouds, assuming the form of an arch. WTiether this curved arrange- 

 ment be actually in a portion of the circumference of a circle, or 

 merely an optical delusion, I will not undertake to assert, but the 

 curve invariably aj)peared 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 cirrostratus. Soon afterwards various 

 beautiful changes to minute cirrocumulus and comoid cirrus were 

 observable. Within the arch lay a long linear bed of cirrostratus, 

 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 atmosphere 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 he said a 

 direct, correspondence between its appearance and the variation of the 



8 



