Nathaniel Bowditch of Salem, Mass., produced his New American Practical Navigator in 1802
The first paragraph of the first chapter of the 1925 edition of Bowditch describes the science of navigation as being divisible into two distinct parts: navigation and nautical astronomy, the point being that navigation, in its more specific form, is a practice of position finding by terrestrial objects, including DR and other piloting practices, and nautical astronomy concerns itself with position finding by celestial objects. Nautical astronomy was such an important aspect of navigation — for the first several thousand years of its existence as a skill — that it was considered its own separate branch of the science involved in mastering vessels at sea. By the 1995 edition, the section on celestial had been reduced to a small chapter alongside several navigation chapters, like Radio Navigation, Radar Navigation
