A Remarkable Solar Halo

Abstract

A SOMEWHAT remarkable halo was visible at Bristol for more than an hour during the morning of Thursday, November 11, between nine and half-past ten. At nine the sky was bright and almost cloudless; a couple of hours or so later it was completely overcast and much rain fell. The halo was white with a slight red coloration on the inside edge, and the whole circle was visible. The most striking feature at 9.30 was the clearness of the sky outside the ring, and its darkness inside. It looked just like a circular cloud of smoke bounded by a bright ring. When measured by my colleague, Mr. Broadbent, the diameter of the halo was found to be 44° 10′.