Example 2. " Course and difference of latitude being given, to find the distance run, and the departure from the meri dian." If a ship runs S. E. by E. from 1° 45' north latitude, and then by observa tion is in 2° 50' south latitude, required her distance and departure T As the ship has crossed the line (i.e. the equator) the north latitude 1° 45' must be added to the south latitude 2° 50'; which makes the difference of latitude 4° 35'. Multiply that by 60, and there appear 275 geogra phical miles. Now draw BO (fig. 15) equal to 275; and BA, making an angle with BC equal to five points, or 56° 15'; upon C erect the perpendiculars CA, to join BA in A. Then will CA be 112, and AB 496 miles; therefore the ship's run has been 496 miles, and her departure from the meridian 411.6 easterly.
Example 3. "Course and departure being given, to find the distance and the difference of latitude." If a ship sails N. E. by E. E. from a port in 3° 15', south latitude, until she depart from her first meridian 412 miles, what latitude will she be in? Draw DA (fig. 16) upon
which erect the perpendicular AB; draw the line AC, making an angle with AB equal to 64° 41', corresponding with 5.1 points. At the distance of 412 miles draw DC, parallel to AB, to cut AC in C ; through the point C draw BC parallel to AD, to cut the meridian AB. Thus AC will give 456 miles for the distance run, and AB 195 miles for difference of lati tude.
readers, who are in search of extensive knowledge in the art of navigation, to the several treatises which have been written by its professors; among which, we be lieve, those published by Mr. Nicholson and the late John Hamilton Moore, have bad the greatest character for utility and general accuracy. With respect to what appertains more to the examination of harbours, coasts, soundings, we refer to SIJUVETING.
Under the article QUADRA/1T, the mode of taking observations at sea will be given, for ascertaining the latitude by solar