Rays

“Summer and Winter rays.—Let us suppose that the rays falling perpendicularly on a given extent of surface, impart to it a certain degree of heat, then it is obvious, that if the same number of rays be spread over twice that extent of surface, their heating power would be diminished in proportion, and that only half of the heat would be imparted. This is the effect produced by the Sun’s rays in the Winter. They fall so obliquely on the Earth, as to occupy nearly double the space that the same number of rays do in the Summer.” —Comstock, 1850

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