Tables Requisite to be Used with the Nautical Ephemeris for Finding the Latitude and Longitude at Sea: Published by Order of the Commissioners of Longitude

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William Richardson; and sold by C. Nourse, and Mess. Mount and Page, 1781 - 237 pages
 

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Page 151 - XVI. of the table requif1te to be ufed with the nautical almanack, under logarithmic rifing, and the time correfpondingto it, is the apparent time" from the neareft noon, when the fun's altitude was obferved; confequently, if the obfervation be made in the forenoon, the time, thus found, muft be taken from 24 hours, and the remainder will be the apparent time from the noon of the preceding day. Example. On the 5th of March 1780, in the afternoon, in latitude 16 24' north, and longitude 138" eaft,...
Page 163 - ... in the Ephemeris; the remainder will be the proportional logarithm of a portion of time to be. added to the hour answering to the nearest distance, to obtain the approximate Greenwich mean time corresponding to the given distance.
Page 147 - XXIII., and, from the column of log. rising, take out the logarithm corresponding, from which logarithm subtract the log. ratio ; the remainder will be the logarithm of a natural number, which, being found in Table...
Page 135 - SuQ ; or Star; an additional dark Glafs, lighter than the common ones, to take off the Glare of the Moon's Light in obferving her...
Page 135 - The principal obfervation for finding the longiiude • at fea is that of the moon from the fun, or from fome remarkable ftar near the zodiac. To do this, the operator muft be furniihed with...
Page 150 - ... centre. RULE. With the apparent time from noon, enter Table XXIII. and from the column of rising take out the logarithm corresponding, to which add the log. co-sine of the latitude, and the log. co-sine of the sun's declination ; their sum, rejecting 20 in the index, will be the logarithm of a natural number, which being subtracted from the natural co-sine of the sum of the declination and latitude, when they...
Page 27 - Add the Difference of the two Numbers taken out of this Table, if the Apparent Argument.
Page 118 - LYNN, Norfolk. See KING'S LYNN. LYNN, T. Supplement to the Horary Tables, for finding the time by inspection, to facilitate the operations for obtaining the latitude and longitude at sea, etc. Stereotype edition.
Page 148 - ... one o'clock. If one be taken in the forenoon, and the other in the afternoon ; the morning one...

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