Bishop's Ring

Abstract

THE letter by Prof. G. H. Stone in NATURE, vol. xxxv. p. 581, is interesting, as showing the disappearance of “Bishop's ring” in Colorado. It has not wholly disappeared here, being still plainly visible about sunset. In the middle of the day, however, I have rarely seen any trace of its red colour since May last year; but up to that time, although growing much fainter, it was still frequently plain here, and I also saw it in the south of England, both in May and June 1886, but only feebly. Since then, when there has been a slight tinge of red, it has usually appeared of a dirty brown colour, very different from what “Bishop's ring” used to be, and I have thought that often it has not been in the upper atmosphere, but at a lower altitude, and most visible when there has been more or less smoke; so that it seemed not improbable the smoke was the cause of it. Has anyone else noticed such a phenomenon connected with smoke? “Bishop's ring,” as still seen at sunset, is evidently not caused by smoke, but doubtless arises from the same circumstances as made it so conspicuous an object at its first appearance in November 1883, and gradually less so since.