The American Ephemeris and Nautical AlmanacU.S. Government Printing Office, 1872 - Nautical almanacs |
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Common terms and phrases
Aldebaran E Apparent Declination Apparent Diff APPARENT PLACES Apparent Right Ascension Aquarii Aquilæ Saturn Arietis W ASCENSION AND DECLINATION Cancri Capricorni d h m Day of Month Declination Right Declination Eclipse Disapp Eclipse II Eclipse Reapp Egress 19 Egress 24 Egress Egress Egress W ELEMENTS FOR FACILITATING Ephemeris Fomalhaut W Frid Geminor Geminorum GREENWICH MEAN GREENWICH MEAN NOON h m h m Horizontal Parallax Hour Angle hour of Long Ingress 19 Ingress 24 Ingress W July Leonis Libræ LUNAR DISTANCES Mean Solar Date Meridian Passage MERIDIAN TRANSIT Midnight Moon MOON'S RIGHT ASCENSION mult Name and Position North Occult OCCULTATIONS OF PLANETS Ophiuchi P. L. of Diff Piscium Pollux E Right Declination Ascension Right Declination Right Sagittarii Saturn W Scorpii Sept Shadow Egress Sidereal Star's Name SUN'S Tauri Thur TRANSIT AT WASHINGTON Transit Ingress True Longitude Tues UPPER TRANSIT Virginis WASHINGTON MEAN NOON
Popular passages
Page 489 - 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 410 - In the year 1887 there will be four eclipses, two of the Sun and two of the Moon. I. — A...
Page 491 - ... equation of time, as has been before explained, is the number of minutes and seconds to be added to or subtracted from the apparent time, or the time given by an observation of the sun, to obtain the mean time. The heading of the column directs the manner in which the equation is to be applied. When there is a change in the course of the month from addition to subtraction or the reverse (as in the months of April and June), the two different directions are separated by a line, while a corresponding...
Page 494 - Greenwich time we have the following rule:— Find in the Almanac the two distances between •which the true distance falls; take out the nearer of these, the hours of Greenwich time over it, and the PL of Diff.
Page 490 - ... pm 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...
Page 490 - Greenwich, and, when greater accuracy is required, should be first interpolated for half the hours and parts of an hour of the Greenwich apparent time. This page is chiefly used when the sun is observed on the meridian, and the local apparent time is oh о™ о".
Page 494 - Minute multiplied by the minutes and parts of a minute of the Greenwich time, and the product added to, or subtracted from the quantity, according as the quantity is increasing or decreasing. Thus, suppose the moon's right ascension and declination are required for 1896, August i, ioh iom 30', astronomical mean time at Greenwich: — Right Ascension.
Page 494 - Greenwich mean time, beginning at noon; the dates are therefore astronomical. All the distances that can be observed on the same day, are grouped together under that date; and the columns are read from left to right, across both pages of the same opening. The letter W. or E. is affixed to the name of the sun, planet or star, to indicate that it is on the west, or east side of the moon.
Page 496 - ... for the moment of Greenwich mean noon. The column Meridian Passage gives the hour, minute and tenth of that passage of the planet over the meridian of Greenwich which occurs next after the noon of the date. The right ascension and declination of a planet are required whenever it has been observed for time, latitude or azimuth. The mode of reducing them to any instant of Greenwich mean time is the same as in the examples for the sun, previously given. The local mean time of passage across any...
Page 495 - Navigator (Table 45}, subtract the PL of Diff. taken from the Almanac. The result is the proportional logarithm of an interval of time to be added to the hours of Greenwich time, taken from the Almanac, when the earlier Almanac-distance is used; to be subtracted from the hours of Greenwich time, when the later Almanac-distance is used.