An Elementary Treatise on Astronomy: Adapted to the Present Improved State of the Science, Being the Fourth Part of a Course of Natural Philosophy, Compiled for the Use of the Students of the University at Cambridge, New England

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Hilliard, Metcalf, and Company, 1827 - 420 pages

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Page 354 - ... must appear to recede from each other, while those in the opposite region would seem gradually to approach, in the same manner as when walking through a forest, the trees toward which we advance are constantly separating, while the distance of those which we leave behind is gradually contracting. The proper motion of the stars, therefore, in opposite regions, as ascertained by a comparison of ancient with modern observations, ought to correspond with this hypothesis ; and Sir W.
Page 251 - Jth of the celestial hemisphere, after which it begins to return ; and as we can ordinarily discern it with the naked eye only when the sun is below the horizon, it is visible only for a certain time immediately after sunset. By and by it sets with the sun, and then we are entirely prevented from seeing it by the sun's light. But after a few days, we perceive, in the morning, near the eastern horizon, a bright star which was not visible before. It is seen at first only a few minutes before sunrise,...
Page 306 - That every planet moves so that the line drawn from it to the sun describes about the sun areas proportional to the times, 2.
Page 124 - That node where the planet passes from the south to the north side of the ecliptic, is called the ascending node ; and the other is the descending node.
Page 354 - Lemonnier and Cassini, and were completely confirmed by Tobias Mayer, who compared the places of eighty stars as determined by Roemer with his own observations, and found that the greater part of them had a proper motion. He likewise suggested that the change of place he had observed among these stars might arise from a progressive motion of the sun towards one quarter of the heavens. La Lande deduced a similar opinion from the...
Page 21 - The general law or fact, in nature, so far as we can observe, is that all bodies attract each other in the direct ratio of their masses, and in the inverse ratio of the squares of the distances.

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