« PreviousContinue »
129. Lat. 55° 9' N. (See similar Ex. p. 30.) This example is worked out as follows: From the logarithm of the distance (increased by 10) subtract log. diff. long. the remainder is the log. cos. latitude, which find in the tables.
130. True courses, &c., N.W.W. 20.0'; W. b. S. 1S. 14.0'; N.N.E. E. 13-8'; S.E.b.S.S. 9.4'; W.N.W.W.
123'; E. N. E. N. 107'; S. W. b. W. 14-8'; S.W.b. W. W. 22.5'. Lat. in 46° 6' S.; long. in 3° 24' W.
131. S. 26° 4' W., 291·7.
132. Lat. 6° 0' 36" N.; long. 100° W.
133. True courses, &c., S.E.b. E. E. 18′ dep. course; N.E.
12.4'; N. N.W. 12:1'; S. S. W. W. 10.5'; S. b. E.
95.5'. Lat. in 68° 48' N.; long. in 8° 29' E.
DEFINITIONS IN NAUTICAL ASTRONOMY, EXPLANATION AND USE OF NAUTICAL ALMANAC, AND PRELIMINARY PROBLEMS.
ASTRONOMICAL AND NAUTICAL TERMS AND DEFINITIONS.
1. NAUTICAL ASTRONOMY teaches the method of finding the place of a ship by means of astronomical observations.
2. The following pages will contain the principal rules for determining the latitude and longitude and the variation of the compass, and a series of examples under each rule will be given for practice. The requisite elements from the Nautical Almanac will be printed after each batch of examples, in order that the student may learn as early as possible the use of that important volume.
3. By the combination of theory with astronomical observations, the motions of the sun, moon, and planets have been determined with great accuracy, so that their places be computed beforehand. An account of these motions and relative positions of the heavenly bodies is printed every year in England, under the name of the Nautical Almanac. In France a similar work is published, called the Connaissance des Tems.