The American Ephemeris and Nautical Almanac

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Página 391 - In the year 1891 there will be four Eclipses : two of the Sun and two of the Moon. I. A total Eclipse of the Moon, May 23, partly visible at Greenwich as a partial Eclipse.
Página 493 - Star, viewed with a telescope that inverts, will disappear and reappear. By "Angle from N. Point" is to be understood the arc included between the Star, when in contact, and the point of intersection of the limb with a circle passing through the North Pole and the centre of the Moon's image ; and by "Angle from Vertex...
Página 483 - ... of the sun is called Solar Time. This is the most natural and direct measure of time. But the intervals between the successive returns of the sun to the same meridian are not exactly equal, owing to the varying motion of the earth around the sun, and to the obliquity of the ecliptic.
Página 484 - The Astronomical Day commences at noon on the civil day of the same date. It also comprises twenty-four hours; but they are reckoned from 0 to 24, and from the noon of one day to that of the next following. The...
Página 490 - a1 + 6' coty ^ must be taken of the same sign with a, and is a sufficiently near approximation to the angle of contact from the north towards the east. For the shadow of a total eclipse, ^ must be taken with a sign opposite that of a.
Página 484 - January 9th, 2 h , astronomical time. The rule, then, for the transformation of civil time into astronomical time is this: — If the civil time is marked AM, take one from the day and add twelve to the hours, and the result is the astronomical time wanted...
Página 483 - EPHEMERIS FOR THE MERIDIAN OF GREENWICH. THE greater portion of this Ephemeris, embracing the positions of the sun and moon; the distances of the moon from the centres of the sun and the four most conspicuous planets, and from certain fixed stars; the ephemerides of the planets Mercury, Venus, Mars, Jupiter, and Saturn, is designed for the special use of navigators. The remainder contains...

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