An Elementary Introduction to the Nautical Almanac, and Astronomical Ephemeris, ... forming a complete epitome of astronomy

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Melling & Payne, 1842 - 60 pages

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Page 5 - Their names are Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricornus, Aquarius, Pisces; the whole occupying a complete circle, or broad belt, in the heavens, called the Zodiac.
Page 25 - The squares of the times of revolution of any two planets are to each other as the cubes of their mean distances from the sun.
Page 32 - He therefore accounts for the 24,000 in the following manner : " If the angle which the plane of the ecliptic makes with the plane of the equator had decreased gradually and regularly, as it was till very lately supposed to do, the two planes would have coincided in about ten ages, 6,000 years...
Page 10 - The seventh sign of the zodiac, which the Sun enters about the 21st of September; it is one of the ancient zodiacal constellations.
Page 52 - The cycle of the moon, golden number, metonic cycle, a period of nineteen years, which being completed, the new and full moons return on the same days of the month.
Page 33 - ... equinoctial. They are distinguished as the Vernal equinox and the Autumnal equinox ; the sun in his annual journey passes through the former on March 21, and through the latter on September 21. Circles of Latitude are great circles passing through the poles of the ecliptic, and perpendicular to the plane of the ecliptic. The angle which the ecliptic makes with the equinoctial is called the obliquity of the ecliptic; it is equal to 23° 27', nearly, and is often denoted by the letter e. These...
Page 13 - ... of the apsides. When the sun and moon are nearest to the earth, they are said to be in perigee. When at their greatest distance from the earth, they are said to be in apogee. When a planet is situated so as to be between the sun and the earth, or so that the sun is between the earth and the planet, then that planet is said to be in conjunction with the sun. When the earth is between the sun and any planet, then that planet is said to be in opposition. It is evident that the two inferior planets...
Page 52 - Stewiacke was on the first day of the week, the first day of the month, the first day of the year, and the first day of the present century.
Page 35 - ... spectator at this place, as we have already shown, the poles of the earth and heavens will lie on the horizon. Leaving the equator and travelling due north along a meridian-line, fore very degree we go north it is evident the pole of the heavens will rise one degree above the horizon ; and when we reach the north pole of the earth, the north pole of the heavens will be on the zenith, or ninety degrees above the horizon. Thus it appears that the latitude of any place is equal to the elevation...
Page 44 - ... its orbit ; Venus, a pea, on a circle 284 feet in diameter ; the Earth also a pea, on a circle of 430 feet ; Mars, a rather large pin's head, on a circle of 654 feet...

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