Navigation and Nautical Astronomy, Part 1Longman, Brown, Green, and Longmans, 1858 |
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Page 98
... haversines . * When the heavenly body is west of meridian , take the hour angle out at top of page of haversines and add thereto the right ascension of the heavenly body : from the sum ( increased if necessary by 24 hours ) subtract the ...
... haversines . * When the heavenly body is west of meridian , take the hour angle out at top of page of haversines and add thereto the right ascension of the heavenly body : from the sum ( increased if necessary by 24 hours ) subtract the ...
Page 136
... haversine hour angle . * reject 30 in the index , and look for the result as a logarithm , and take out its natural number . * Or , instead of log . haversine , twice the log . sine of half the hour angle ( rejecting in this case 40 ...
... haversine hour angle . * reject 30 in the index , and look for the result as a logarithm , and take out its natural number . * Or , instead of log . haversine , twice the log . sine of half the hour angle ( rejecting in this case 40 ...
Page 145
... haversines of the two last arcs put down ; the sum , rejecting 10 in index , is the log . haversine of arc 2 , which take from the Tables . 10. To find are 3. Under arc 1 put zenith distance at greater bearing , and take the difference ...
... haversines of the two last arcs put down ; the sum , rejecting 10 in index , is the log . haversine of arc 2 , which take from the Tables . 10. To find are 3. Under arc 1 put zenith distance at greater bearing , and take the difference ...
Page 150
... haversine of polar angle ; the result , rejecting 10 in the index , is the log . haversine of an arc , which take from the tables and call arc A. Add together versine of arc A and versine of the differ- ence of polar distances ; the sum ...
... haversine of polar angle ; the result , rejecting 10 in the index , is the log . haversine of an arc , which take from the tables and call arc A. Add together versine of arc A and versine of the differ- ence of polar distances ; the sum ...
Page 151
... Haversine polar angle Haversine arc A Arc A. Vers . arc A • Vers . difference polar distances Vers . arc 1 Arc 1 • 9.986177 • 9.995241 9.226458 9.207876 47 ° 22 ′ 30 ′′ 0322696 107 5319 0328122 47 ° 47 ' 16 " To find arc 2 . To find arc ...
... Haversine polar angle Haversine arc A Arc A. Vers . arc A • Vers . difference polar distances Vers . arc 1 Arc 1 • 9.986177 • 9.995241 9.226458 9.207876 47 ° 22 ′ 30 ′′ 0322696 107 5319 0328122 47 ° 47 ' 16 " To find arc 2 . To find arc ...
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Common terms and phrases
24 hours altitude for index apparent solar April 27 ascension mean sun ascension of mean auxiliary angle celestial equator chro chronometer showed colatitude compass bearing compass course correction in altitude cosec course and distance deviation diff east of meridian 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 longitude by chronometer mean time nearly moon Moon's declin moon's semidiameter Nautical Almanac observed altitude observed meridian altitude P.M. mean pass the meridian point of Aries pole proportional logarithm refraction required the latitude required the longitude required the true required the variation Right asc Right ascension mean ship mean ship's head sidereal sidereal clock star subtract Sun's declination sun's L. L. sun's lower limb true altitude true bearing true course true distance vers versines zenith distance
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'.