The Nautical Almanac and Astronomical Ephemeris for the Year ...order of the Lords Commissioners of the Admiralty, 1850 |
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Common terms and phrases
Aldebaran W Antares Jupiter Apparent Declination APPARENT PLACES Apparent Right Ascension Aquarii Arietis Saturn Arietis W ASCENSION AND DECLINATION Cancri Capricorni Ceti diff Earth Eclipse Disapp Eclipse Reapp Egress 19 Egress 22 EPHEMERIS Equation Fomalhaut W Frid FRIDAY Geminor Geocentric Greenwich Mean Greenwich Transit Heliocentric Hour of Long Ingress 19 Ingress 20 Jupiter a Aquila Jupiter W Leonis Libræ LUNAR DISTANCES Mars SUN Mean Noon Meridian Longitude Meridian of Greenwich MONDAY Month Moon I. L. MOON'S RIGHT ASCENSION Name and Position Occult Ophiuchi Pegasi W Pollux W R. A. Dec Regulus E Right Asc Sagittarii SATURDAY Saturn W Scorpii Semi Semidiam Semidiameter Shadow Egress Spica mg Spica my Antares Spica ng Star's Name SUN Pollux SUNDAY Tauri Thur THURSDAY TRANSIT AT GREENWICH Transit Egress True Dist Tues TUESDAY UPPER TRANSIT Variation of Declination Variation of Right Vect Virginis WEDNESDAY
Vinsælir kaflar
Síða 604 - Ascension, and the interval between the departure of any meridian from the mean Sun and its succeeding return to it is the duration of the mean solar day. Clocks and chronometers are adjusted to mean solar time ; so that a complete revolution (through 24 hours) of the hour hand of...
Síða 604 - ALL the articles of the Ephemeris have been computed for Greenwich MEAN solar time ; and where they are given for apparent solar or sidereal time, it has been chiefly for the convenience of astronomers. A day is the interval of time between the departure of any meridian from a heavenly body and its succeeding return to it, and derives its name from the body with which the motion of the meridian is compared. The interval between the departure and return of a meridian to the Sun is called a solar day...
Síða 630 - Tables for determining the Latitude by Observations of the Pole Star out of the Meridian. The method of using them is as follows : — From the observed altitude, when corrected for the error of the injtrument, refraction, and dip of the horizon, subtract i'.
Síða 613 - Lunar Distance has been observed on the surface of the Earth, and reduced to the centre, by clearing it of the effects of parallax and refraction, the numbers in the« pages enable us to ascertain the exact Greenwich mean time at which the objects would have the same distance.
Síða 608 - Sidereal Time at Mean Noon is the angular distance of the first point of Aries, or the true vernal equinox, from the meridian, at the instant of mean noon : it is therefore the Right Ascension of the mean Sun, or the time shown by a sidereal clock at Greenwich, when the mean time clock indicates oh om o*.
Síða 608 - Noon is the angular distance of the First point of Aries, or the true Vernal Equinox, from the meridian, at the instant of Mean Noon : it is therefore the Right Ascension of the Mean Sun, or the time which ought to be shown by a Sidereal Clock at Greenwich, when the Mean Time Clock indicates O h 0° 0'.
Síða 606 - Sun from the meridian, or the portion of time to be added to or subtracted from, (according to the precept at the head of the column,) Greenwich apparent noon to obtain the corresponding mean time at the same meridian, or the time which should be shown by a mean time clock.
Síða 531 - In the year 1843 there will be two Eclipses of the Sun and one of the Moon.
Síða 604 - As the time deduced from observation of the true Sun is called true or apparent time, so the time deduced from the mean Sun, or indicated by the machines which represent its motion, is denominated mean time.
Síða 577 - The Moon's Libration is here supposed to take place in the plane of her orbit ; and by the time of the greatest Libration of her apparent Disc is to be understood the instant at which, to an observer at the centre of the Earth, the variation of the Disc from its mean state has attained its maximum. The right-hand column indicates the quadrant of the Moon's Disc in which the Libration takes place, and in which the greatest change of the Moon's surface will become visible.