TCD MS 10515 folio 58r
[April 28th 1916]
iated upward across the sky, brightening the dark watery clouds with diverging streaks of sunshine. It was as though the Eastern sky was fulfilling its promise of the coming day while the west was still gilded with the glories of approaching night. It was certainly a strange effect to see the bright beams of light diverge from opposite horizons to lose themselves in the cloudy zenith as though some mighty change was immiment in the orderly course of Nature. How is this phenomenon produced that gives a picture of a double sunset.
I suppose that the clouds high aloft in the heavens acted on the sun’s *rays like a gigantic convex lens, and the rays which diverged from the setting sun were thus refracted and brought
*Perhaps more accurately a concave mirror acting as a reflecting surface.