The Nautical Almanac and Astronomical Ephemeris for the Year 1845

The Nautical Almanac and Astronomical Ephemeris for the Year 1845

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This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1841 edition. Excerpt: ...the equations opposite to the 15th and loth days of the month, a black line, indicating that the change occurs between the Apparent Noons of those days. The upper precept applies to all the quantities above the black line; and the lower precept to all the quantities below it: that is, in the instance referred to, the Equation of Time is to be added to Apparent Time from the 1st of April to the instant at which the equation becomes 01, which happens between the noons of the 15th and loth days of the month: but after that instant the equation is to be subtracted from Apparent to obtain Mean Time. Page II. of each Month. '. The Sun's Apparent Right Ascension and Declination at mean noon have been deduced from its Apparent longitude and latitude given at page III., and the apparent obliquity of the ecliptic at page 266. They denote the apparent position of the true Sun with reference to the equator, and the true equinox, at the instant the Greenwich mean time clock, or chronometer, indicates Ob 0" 0," or when the hoar angle of the true Sun is equal to the equation of time. To find the Right Ascension and Declination for any other mean time and place, a at 9" 20 A.M. March 2, 1845, in longitude 98, or 6" 32TM, West of Greenwich. The astronomical time, corresponding to 9h 20m A.M. March 2, is 21" 20 from the noon of March 1, or March 1 21h 20m, agreeably to what has been said before. The longitude, being West of Greenwich, must be added to March l" 21h 20TM, and the result, March 2d 3h 52m, is the corresponding Greenwich mean time, for which the Right Ascension and Declination are to be found. The difference between the Right Asceasions on March 2 and March 3 is 3TM 43"'84, that is, more

Product details

  • Paperback | 34 pages
  • 189 x 246 x 2mm | 82g
  • United States
  • English
  • black & white illustrations
  • 123679964X
  • 9781236799647