The Light of Planets

Abstract

A FEW facts relative to this subject may be interesting. At Plymouth on August 12, about 9 o'clock, favoured with a beautifully clear horizon, the brilliancy of Mars was so great that it cast a distinctly black shadow on a piece of white paper from an ordinary walking stick held at a distance of 4½ inches; the outline of the hand, under the same conditions, was also easily perceptible. A faint, yet decided, darkening of the white cliffs of the shore was caused by a person standing upright—the slope being about 45°. The point of observation was at the extreme north-west of the Sound, and the splendour of the planet's light reflected from three or four miles of water is perhaps unrivalled.