Aurora Borealis observed in Day-light

Extract

An Account of an Aurora Borealis, observed in day-light at Aberfoyle in Perthshire, on the 10th February 1799, by Patrick Graham, D. D. minister of Aberfoyle, was communicated by the Reverend Dr Finlayson.

“On the 10th of February 1799, about half-an-hour past 3 o'clock P. M., the sun being then a full hour above the horizon, and shining with an obscure lustre through a leaden-coloured atmosphere, I observed,” says Dr Graham, “the rare phenomenon of an aurora borealis by day-light. The weather, for several days before, had been intensely cold; and during the two preceding days, much snow had fallen. On this day a thaw had come on, and the temperature of the air was mild. The general aspect of the sky was serene. Some dark clouds hung on the horizon between S. W. and W. I was intensely observing a large halo about the fun, of about 20 degrees in semidiameter : It exhibited the prismatic colours, though obscurely, except in one quarter, where it coincided with the skirt of a dark cloud on the horizon, almost directly west. In that portion of the halo, the colours of the iris were very distinctly exhibited.