Tables for facilitating the determination of the latitude at sea by the simultaneous altitudes of two stars

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R.B. Bate, 1849 - Navigation - 48 pages
 

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Page v - Tables for facilitating the determination of the Latitude at Sea by the Simultaneous Altitudes of two Stars. 8° 1849.
Page 6 - NWSB be the rational horizon, NS the meridian, Z the zenith, and P the pole of the heavens. Let X and Y be the same or different heavenly bodies ; ZX, ZY, PX, PY, XY, arcs of great circles. Then PZ is the colatitude of the place, PX and PY are respectively the polar distances of X and Y, ZX and ZY their zenith distances, ZPX, ZPY their hour angles, SZX, SZY their true bearings from the S.
Page 2 - Rule for computing the Latitude at Sea from the Altitudes of two Fixed Stars observed at the same time.
Page 7 - In selecting a couplet of stars for simultaneous observation, it will not be proper to take those which at their meridian passage pass very near the zenith, or which pass the meridian the one north and the other south of the zenith. The...
Page 10 - The sum, rejecting the tens from the index, will be the log. of...
Page 12 - E. 19° 26' 20" E. Ans., 41° 22' N. (152.) March 2, 1845, in latitude by account 41° 20' N. long., 60° E., the altitudes of the two following stars were observed at the same time, required the true latitude. True alt. a Andromeda!. Bearing. True alt. a Tauri. Bearing. 73° 14' SbE 18° 27' 30
Page 39 - Their difference or sum being taken according to the position of the stars with reference to the pole and zenith, as shewn in Fiys.
Page 6 - Hence, in the triangle WPE, knowing the angle WPE and the two sides PW and PE, we can compute...
Page 9 - ... then the altitude of the other star, and lastly that of the first one again, noting the times.

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