Before the Nautical Almanacs

Abstract

From the earliest times astronomical information was used for calendars, time, climate, farming, seasons, and phenomena predictions. The Sun, Moon, five planets, and star patterns were known. Treatises and tables were used to calculate positions of planets. There are records of astronomical data in different forms from different countries. Ptolemy created accurate geometrical models for compiling positions of planets. The Chinese had records of celestial phenomena. The Mayan had their codices containing almanacs. The Islamic cultures had astronomical zijes of astronomical tables. In the 15th and 16th centuries there were a number of almanacs printed with the printing presses. In 1628 Kepler produced the Rudolphine Tables, the first real improvement since Ptolemy. With the printing press many almanacs were published with astronomical data and other information. The Royal Observatory at Greenwich was founded in 1675. The Connaisance des Temps was first published in 1678. In 1700 the Calendar Edict introduced the Gregorian Calendar to Germany and required a stamp tax on calendars, which supported the astronomers of the Berlin Observatory. Navigators could determine latitude by angular measurements of Polaris or the Sun. Different navigational instruments were developed for measuring celestial angles with increasing precision.