Navigation and Nautical Astronomy: For the Use of British Seamen |
Common terms and phrases
apparent Astronomy axis barometer celestial concave celestial equator centre chronometer circle colatitude compass computed corresponding cosec course and distance declination diff dist earth east ecliptic equator error feet fixed star greater Greenwich date Greenwich mean heavenly body height horizon hour angle index correction instrument interval logarithm longitude by chronometer mean noon mean time nearly miles moon motion Naut Nautical Almanac object observed altitude observed meridian altitude parallax parallel pass perpendicular plane point of Aries polar pole R. A. mean sun radius refraction required the latitude required the true result right ascension round rule sailing screw semid semidiameter sextant ship mean subtract Sun's decl sun's L. L. supposed surface taken telescope tide true latitude true longitude variation vers versine zenith distance
Popular passages
Page 174 - In very hot weather, the falling of the mercury indicates thunder. 3. In winter, the rising presages frost: and in frosty weather, if the mercury falls three or four divisions, there will be a thaw.
Page 174 - ... 6. In fair weather, when the mercury falls much and low, and thus continues for two or three days before the rain comes, then a deal of wet may be expected, and probably high winds.
Page 174 - In very hot weather, the falling of the mercury foreshows thunder. 3. In winter, the rising presages frost ; and in frosty weather, if the mercury falls three or four divisions, there will certainly follow a thaw. But in a continued frost, if the mercury rises, it will certainly snow.
Page 29 - CB : CA : : sin A : sin B. For, with A as a centre, and AD equal to the less side...
Page 45 - The longitude of a heavenly body is the arc of the ecliptic intercepted between the first point of Aries and the...
Page 48 - The azimuth is the arc of the horizon intercepted between the north or south point, and the circle of...
Page 174 - These are esteemed the best of any general rules hitherto made : 1. The rising of the mercury presages, in general, fair weather; and its falling, foul weather, as rain, snow, high winds, and storms. 2. In very hot weather, the falling of the mercury indicates thunder.
Page 111 - S. of the sun), the index correction was + 2' 40", and the height of the eye above the sea was 15 feet; required the latitude. 5. April 20, 1878, in long. 56° 30' W., the observed meridian altitude of the moon's LL below Pole was 18° 26' 30", the index correction was —2' 40", and the height of the eye above the sea was 18 feet; required the latitude.
Page 217 - N. 12 miles, the index correction was + 3' 50", and the height of the eye above the sea was 18 feet ; required the true latitude, the latitude by account being 51° N., and the longitude 50° 10
Page 229 - LL was 50° 13' 10"; the index correction was — 4' 10", and the height of the eye above the sea was 20 feet : required the variation of the compass.