Guy's Elements of astronomy : and an abridgment of Keith's New treastise on the use of the globes . X, fig. 3;) N the north pole, S the south pole,P the north pole star, to which, and to the opposite partof the heavens, the axis always points. These extremi-ties in the heavens appear motionless, while all theother parts seem in a continual state of revolutiojuThe circle of motion in the heavenly bodies seems toincrease with the distance from the poles. The Tropics cire two small circles parallel to the equa-tor, at 23J degrees distance from it; that to the northis called the tropic of Cancer,
Guy's Elements of astronomy : and an abridgment of Keith's New treastise on the use of the globes . X, fig. 3;) N the north pole, S the south pole,P the north pole star, to which, and to the opposite partof the heavens, the axis always points. These extremi-ties in the heavens appear motionless, while all theother parts seem in a continual state of revolutiojuThe circle of motion in the heavenly bodies seems toincrease with the distance from the poles. The Tropics cire two small circles parallel to the equa-tor, at 23J degrees distance from it; that to the northis called the tropic of Cancer, and that to the south thetropic of Capricorn. The Polar circles circumscribe the poles of theworld, at the distance of 23^ degrees. That on thenorth is called the Arctic, and that on the south theAntarctic circle. The distance of these polar circles from the poles being fixed at23|*>(Uie same as the tropics from the equator) is because it is the line ofboundary between light and darkness, when the sun is on either of thetropics, and throws his beams over and beyond the pole. Hfi^r ^^ FUtt 6\. The Meridians are so called because, as the earthrevolves on his axis, when any one of them is oppositeto the sun it is mid-day or noon along that line. Twen-ty-four of these lines are usually drawn on the globes^to correspond with the twenty-four hours of the that these are the only ones that can be imagined,for every place that lies ever so little east or west ofanother place has a different meridian. Suppose the upper 12 (plale IX. fig. 3.) to be opposite the sun, itwill of course be noon along that line, and the«next meridian marked 1»being 15^ east, will have passed the meridian 1 hour, consequently itwill there be one in the afternoon, and so on, according to the order ofthe figures, to the lower 12, which being the part of the earth turneddirectly from the sun, it will be midnight on that meridian: as you pro-ceed round, the next meridian will be one in the morning, th
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Keywords: ., bookcentury1800, bookdecade1860, booksubjectastronomy, bookyear18
