An epitome of navigation [electronic resource] : containing the doctrine of plain and spherical triangles, and their use and application in plain sailing, mercator's sailing, and great circle sailing, as also in astronomy and geography, and rules for finding the variation of the compass, and correcting the course. Together with tables of the sun and stars right ascension and declination, of the latitude and longitude of places, of meridional parts. Likewise a traverse-table, a perpetual almanack; and other things very useful in the art of navigation. And the logarithm sines and tangents, with the logarithms of natural numbers, from 1 to 10000, according to those exact tables formerly set forth. By Henry Gellibrand.