Читать книгу The Natural History of Pliny (Vol. 1-6) - Pliny the Elder - Страница 20

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The three planets, which, as we have said, are situated above the sun205, are visible when they come into conjunction with him. They rise visibly206 in the morning, when they are not more than 11 degrees from the sun207; they are afterwards directed by the contact of his rays208, and when they attain the trine aspect, at the distance of 120 degrees, they take their morning stationary positions209, which are termed primary; afterwards, when they are in opposition to the sun, they rise at the distance of 180 degrees from him. And again advancing on the other side to the 120th degree, they attain their evening stations, which are termed secondary, until the sun having arrived within 12 degrees of them, what is called their evening setting becomes no longer visible210. Mars, as being nearer to the sun, feels the influence of his rays in the quadrature, at the distance of 90 degrees, whence that motion receives its name, being termed, from the two risings, respectively the first and the second nonagenarian211. This planet passes from one station to another in six months, or is two months in each sign; the two other planets do not spend more than four months in passing from station to station.

The two inferior planets are, in like manner, concealed in their evening conjunction, and, when they have left the sun, they rise in the morning the same number of degrees distant from him. After having arrived at their point of greatest elongation212, they then follow the sun, and having overtaken him at their morning setting, they become invisible and pass beyond him. They then rise in the evening, at the distances which were mentioned above. After this they return back to the sun and are concealed in their evening setting. The star Venus becomes stationary when at its two points of greatest elongation, that of the morning and of the evening, according to their respective risings. The stationary points of Mercury are so very brief, that they cannot be correctly observed.