An Elementary Treatise on Astronomy: In Two Parts, the First Containing a Clear and Compendious View of the Theory, the Second, a Number of Practical Problems, to which are Added Solar, Lunar, and Other Astronomical TablesE.C. & J. Biddle, 1857 - 477 pages |
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Common terms and phrases
affirmative apparent diameter argument argument of Latitude ascension and declination astronomical axis body called centre circle comet computed Consequently corrected corresponding Cotang Diff difference diurnal motion dominical letter earth eclipse equal equator equatorial parallax equinox Evection fixed star formulæ full moon geocentric latitude given place Greenwich heliocentric Hence horizon horizontal parallax hour angle hourly motion hourly variation interval Jupiter less log.cos logarithm longitude and latitude mean anomaly mean longitude mean noon Mercury meridian motion in longitude Nautical Almanac nearly negative node nutation obliquity obtained orbit parallax parallel perigee perihelion period perpendicular planet pole position quantities radius vector refraction result revolution right ascension satellites Saturn semidiameter sidereal sine solar subtract sun's longitude sun's mean taken from table tang tangent telescope tides tion triangle true true longitude Venus vernal equinox zenith distance
Popular passages
Page 13 - The azimuth of a body is the arc of the horizon intercepted between the north or south point of the horizon, and a vertical circle passing through the body.
Page 10 - ... by an ether diffused through space ; but if so, how happens it that the planets also have not been retarded ? This the author attempted to show might be the case, although the phenomenon might pass unobserved.
Page 182 - ... before. This was the star in question. It was then as bright as Sirius, and continued to increase till it surpassed Jupiter when brightest, and was visible at mid-day. It began to diminish in December of the same year, and in March 1574, had entirely disappeared.
Page 71 - Year, and consists of 365 days, в hours, 9 minutes, and 9. 6 seconds, which is invariable. The Tropical Year is the interval between two consecutive returns of the Sun to the Vernal Equinox.
Page 108 - The sidereal time of our common noon is given in the nautical almanac for every day in the year...
Page 7 - Uranus, and Neptune. Five of these planets, namely — Mercury, Venus, Mars, Jupiter, and Saturn are visible to the naked eye, and were known to the ancients. Uranus, the Asteroids, and Neptune have been discovered in modern times by the aid of the telescope ; and there may be others yet undiscovered.
Page 13 - The Altitude of a heavenly body is the arc of a vertical circle, intercepted between the horizon and the centre of the body.
Page 122 - We may, also, regard the motion of the centre of the shadow in longitude, and the motions of the moon in longitude and latitude, as being uniform during the continuance of the eclipse.
Page 12 - The declination is reckoned north or south, according as the body is on the north or south side of the equator.
Page 55 - The Polar Circles are two small circles parallel to the equator, and at a distance from its poles equal to the obliquity of the ecliptic.