## Navigation and Nautical Astronomy: The Practical Part, Containing Rules for Finding the Latitude and Longitude, and the Variation of the CompassJohn Weale, 1853 - 279 pages |

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24 hours altitude for index apparent altitude apparent solar April 27 ascension mean sun astronomical celestial equator chro chronometer showed colatitude compass course correction in altitude cosec decl deviation diff difference of latitude ecliptic Elements from Nautical find the latitude Greenwich date Greenwich mean noon haversines heavenly body height of eye horizontal parallax hour angle Index cor index correction July July 12 June mean solar mean time nearly moon Moon's declination moon's semidiameter Nautical Almanac observed altitude observed meridian altitude P.M. mean pass the meridian point of Aries polar distance pole proportional logarithm refraction required the latitude required the longitude required the true Right asc Right ascension mean sea 20 feet ship mean ship's head sidereal star subtract Sun's declination sun's L. L. sun's lower limb true altitude true bearing true course true difference true distance versine zenith distance

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Page 12 - Fig. 3) loaded on the circular side with lead sufficient to make it swim upright in the water: to this is fastened a line about 150 fathoms long, called the Log-line, which is divided into certain spaces called knots, and is wound on a reel (see Plate VI.

Page 60 - The hour angle of a heavenly body, is the angle at the pole between the celestial meridian and the circle of declination passing through the place of the body ; thus, zpx is the hour angle of x.

Page 54 - ... whirling motion of the earth about its axis, the parts near the equator, which have the greatest velocity, acquire thereby a greater distance from the centre than the parts near the poles. By actual measurement of a degree of latitude in different parts of the earth, it is found...

Page 61 - The apparent solar day is the interval between two successive transits of the sun's centre over the same meridian.

Page 59 - The right ascension of a heavenly body is the arc of the equator, intercepted between the first point of Aries and the circle of declination, passing through the place of the...