Selenographia: sive Lunae descriptio (Selenography: or a Description of the Moon), a book by Johannes Hevelius, published in 1647.
Cover: parchment, cardboard, gilded embossing: 19th century.
An engraving GG (between pp. 476-477)
Etched title page
Selenography is an outcome of the regular observations conducted in 1643-1645 by Hevelius from the astronomical observatory in Gdansk which he set up in 1641. For 150 years, the book was one of the basic materials for the study of the Moon’s surface, alongside Grimaldi's map in Riccioli’s Almagestum novum, and the map by Cassini of the Paris Observatory. It was only in the mid-18th century that Tobias Mayer introduced a new, more precise technique of drawing lunar maps using micrometrical measurements. Johannes Hevelius began naming the features of the Moon’s surface with geographical names derived from classical geography, but the majority of his suggestions were eventually rejected by selenographers. Ultimately, of nearly 300 names suggested by Hevelius, only 10 are still in use on contemporary lunar maps (e.g. the Alps, and the Apennines), among those only four are used in the places indicated by Hevelius. Selenography also contains a description of the solar observations conducted by Hevelius from 1642-1644.