A complete epitome of practical navigation : containing all necessary instructions for keeping a ship's reckoning at sea: with the most approved methods of ascertaining the latitude, by meridian, single, or double altitudes, and the longitude, by chronometers, or lunar observations; including a journal of a voyage from London to Madeira; and every other requisite to form the complete navigator; the whole being rendered perfectly easy, and illustrated by several engravings /by J. W. Norie.