Earth Axis
“Now it is the inclination of the Earth’s axis, as above described, which causes the lengths of the days and nights to differ at the same place at different seasons of the year, for on reviewing the positions of the globe at A, it will be observed that the line formed by the enlightened and dark hemispheres, does not coincide with the line of the axis and the pole, but that the line formed by the darkness and the light, extends obliquely across the line of the Earth’s axis, so that the north pole is in the light while the south is in the dark. In the position A, therefore, an observer at the north pole would see the sun constantly, while another at the south pole would not see it at all. Hence those living in the north temperate zone, at the season of the year when the earth is at A, or in the Summer, would have long days and short nights, in proportion as they approached the polar circle; while those who live in the south temperate zone, at the same time, and when it would be Winter there, would have long nights and short days in the same proportion.” —Comstock, 1850
Source
J. L. Comstock A System of Natural Philosophy: Principles of Mechanics (: Pratt, Woodford, and Company, 1850) 306
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