A Complete Set of Nautical Tables, Containing All that are Requisite, with the Nautical Almanac, in Keeping a Ship's Reckoning at Sea, and Ascertaining the Latitude and Longitude by Celestial Observations; Including a New, Accurate, and Extensive Table of the Latitude and Longitude of the Principal Ports ... with Several Other New and Improved Tables. To which is Prefixed a Copious Explanation of the Tables