Navigation and Nautical Astronomy, Part 1Longman, Brown, Green, and Longmans, 1858 |
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Page 30
... interval , the deviation of the compass for each course on account of local attraction , the variation of the compass , the leeway , the velocity and direction of current ( if any ) & c . , constitutes what is called the Day's Work ...
... interval , the deviation of the compass for each course on account of local attraction , the variation of the compass , the leeway , the velocity and direction of current ( if any ) & c . , constitutes what is called the Day's Work ...
Page 60
... interval between the sun's leaving the first point of Aries , and returning to it again . A sidereal year is the interval between the sun's leaving a fixed point , as a star , and returning to that point again . The equinoctial points ...
... interval between the sun's leaving the first point of Aries , and returning to it again . A sidereal year is the interval between the sun's leaving a fixed point , as a star , and returning to that point again . The equinoctial points ...
Page 61
... interval between two successive transits of the first point of Aries over the same meridian . It begins when that point of Aries is on the meridian . The apparent solar day is the interval between two suc- cessive transits of the sun's ...
... interval between two successive transits of the first point of Aries over the same meridian . It begins when that point of Aries is on the meridian . The apparent solar day is the interval between two suc- cessive transits of the sun's ...
Page 63
... interval between two successive transits of the mean sun over the same meridian . It begins when the mean sun is on the meridian . To find the daily motion of the mean sun in the equator . 21. The mean solar year , or the time the sun ...
... interval between two successive transits of the mean sun over the same meridian . It begins when the mean sun is on the meridian . To find the daily motion of the mean sun in the equator . 21. The mean solar year , or the time the sun ...
Page 64
... interval of two successive transits of a fixed star : or supposing the first point of Aries to be invariable between two successive transits of the first point of Aries . A mean solar clock is a clock adjusted to go 24 hours during one ...
... interval of two successive transits of a fixed star : or supposing the first point of Aries to be invariable between two successive transits of the first point of Aries . A mean solar clock is a clock adjusted to go 24 hours during one ...
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Common terms and phrases
24 hours altitude for index apparent distance April 27 ascension mean sun ascension of mean auxiliary angle celestial concave celestial equator chro colatitude compass bearing correction in altitude cosec decl diff east of meridian Elements from Nautical EXAMPLES find the latitude Greenwich date Greenwich mean haversines heavenly body height of eye horizontal parallax hour angle Index cor index correction June longitude by chronometer mean time nearly moon moon's declination Moon's right Moon's semi 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 sidereal star subtract Sun's declination sun's L. L. sun's lower limb true altitude true bearing true distance true zenith distance vers versines zenith dist
Popular passages
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 54 - ... consequence of the 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.
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 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...
Page 61 - The apparent solar day is the interval between two successive transits of the sun's centre over the same meridian.
Page 63 - Mean Solar Day is the interval between two successive transits of the mean sun over the same meridian ; it begins when the mean sun is on the meridian.
Page 13 - ... ascertained at sea by observing the magnetic bearing of- the sun when in the horizon, or at a given altitude abo-ve it. From this observation the true bearing is found by rules given in nautical astronomy. The difference between the true bearing and the observed bearing by compass determines this correction.
Page 258 - W., and at the same time the observed altitude of the sun's lower limb was 21° 40' 45", the index correction was — 2' 18", and the height of the eye above the sea was 14 feet : required the variation.
Page 199 - To the hour angle thus found, add the star's right ascension; and from the sum, increased if necessary by 24 hours, subtract the right ascension of the mean sun ; the remainder is mean time at the place at the instant of observation.
Page 54 - ... path of the sun as seen from the Earth, and is called the Ecliptic. The plane of the Earth's equator, extended till it meets the concave surface of the heavens, forms what is called the Celestial Equator, or the Equinoctial. The ecliptic and the equinoctial form an angle of 23° 28', and this angle is called the Obliquity of the Ecliptic. The axis of the Earth, therefore, instead of being perpendicular to the plane of its orbit, is inclined to it at an angle of (90° — 23° 28') 66° 32'.