Note 40 — Chapter VII

The late George Adams, in his Philosophy, treating of refraction, states, that "at the horizon, in this climate, (England) it is found to be about thirty-three minutes. In climates near the equator, where the air is pure, the refraction is less; and in the colder climates, nearer the pole, it increases exceedingly, and is a happy provision for lengthening the appearance of the light at those regions so remote from the sun. Gassendees relates, that some Hollanders, who wintered in Nova-Zembla, in latitude seventy-five degrees, were agreeably surprised with a sight of the sun seventeen days before they expected him in the horizon. This difference was owing to the refraction of the atmosphere in that latitude."—Adams' Philosophy, v. 4, p. 112, Philadelphia, 1807.