The American Ephemeris and Nautical AlmanacU.S. Government Printing Office, 1860 - Nautical almanacs |
Other editions - View all
Common terms and phrases
Aldebaran E Antares W Apparent Declination APPARENT PLACES Apparent Right Ascension Aquarii Aquilæ Fomalhaut Arietis Aldebaran ASCENSION AND DECLINATION Astr Coefficient d h m Day of Month Eclipse Disapp Eclipse II Eclipse Reapp Egress 19 Egress 26 Ephemeris Fomalhaut W Geminor GREENWICH MEAN GREENWICH MEAN NOON Ingress 19 Ingress 26 Ingress Egress Latitude Leonis LUNAR DISTANCES Mean Solar Meridian Passage Midnight Moon MOON'S RIGHT ASCENSION Nachr Name and Position Name and R.A. NOON AND MERIDIAN Occult Ophiuchi P. L. of Diff P. L. of IXh Parallax Pegasi E Pegasi Mars Piscium Pleiadum Pollux Regulus PRINCIPAL FIXED STARS R.A. Dec R.A. In Dec R.A. of Star Regulus Saturn Jupiter Sagittarii Saturn Jupiter Spica Semi Shadow Egress Sidereal Day Sidereal Oh Spica Antares Star's Name SUN'S Tauri Thur TRANSIT AT WASHINGTON Transit Ingress True Longitude Tues UPPER TRANSIT Var.of Dec Venus Virginis WASHINGTON MEAN WASHINGTON MERIDIAN
Popular passages
Page 473 - The want of uniformity in the sun's motion in right ascension arises from two different causes ; one, that the sun does not move in the equator, but in the ecliptic ; the other, that the sun's motion in the ecliptic is not uniform. To avoid the irregularity in time caused by the want of uniformity in the sun's motion, a fictitious sun, called a Mean Sun, is supposed to move in the equator with a uniform velocity. Mean Time, which is perfectly equable in its increase, is measured by the motion of...
Page 491 - PETER8' formulas given in his Numerus Constans Nutationis. § These formulas are reprinted in the volume of this ephemcris for 1855. The Mean Places of the Fixed Stars are taken from the list of stars in the English Nautical Almanac for 1855, combined with that given in the Astronomical Observations made during the Year 1846 at the National Observatory, Washington. The Apparent Places of the Fixed Stars have been obtained by means of a set of tables constructed and printed in the office of this work,...
Page 474 - January 9th, 2h, 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 ; if the civil time is marked PM, take away the designation PM, and the astronomical time is had witJiout further change.
Page 473 - It is divided into 24 hours. The sidereal hours are counted from 0 to 24, commencing with the instant of the passage of the true vernal equinox over the upper meridian and ending with...
Page 398 - In the year 1888 there will be five eclipses, three of the Sun and two of the Moon. I. — A Total Eclipse of the Moon, January 29, visible at Washington and generally throughout North and South America, Europe, Asia, and Africa.
Page 473 - A Solar Day is the interval of time between two successive transits of the sun over the same meridian; and the hour-angle of the sun is called Solar Time.
Page 474 - 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...
Page 473 - This is the most natural and direct measure of time. But the intervals between the successive returns of the sun to the meridian are not exactly equal, but depend upon the variable motion of the sun in right ascension. The want of uniformity in the sun's motion in right ascension arises from two different causes...