[Map of the Moon] Die sichtbare Seite der Mond-Oberflache bei voller Beleuchtung Nach Beer u Madlers Karte .

Map of the Moon, based upon the work of Johann Heinrich von Mädler ( 1794 -1874) one of the most important German astronomer's of the late 19th Century.

Mädler began giving academic lessons as a private tutor and in this way met Wilhelm Beer, a wealthy banker in 1824. In 1829, Beer decided to set up a private observatory with a 95 mm refractor telescope made by Joseph von Fraunhofer, when Mädler would find his earliest work as an Astronomer.
In 1830, Mädler and Beer began producing drawings of Mars which later became the first true maps of that planet. They were the first to choose what is today known as Sinus Meridiani as the prime meridian for Mars maps and made a preliminary determination for Mars' rotation period, which was off by almost 13 seconds.
A later determination in 1837 was off by only 1.1 seconds. Madler and Beer also produced the first exact map of the Moon, Mappa Selenographica, published in four volumes in 1834-1836. In 1837, their description of the Moon ( Der Mond) was published. Both were the best descriptions of the Moon for many decades, not superseded until the map of Johann Friedrich Julius Schmidt in the 1870s. Beer and Mädler drew the firm conclusion that the features on the Moon do not change, and there is no atmosphere or water.
In 1836, Johann Franz Encke appointed Mädler an observer at the Berlin Observatory. In 1840, Mädler was appointed director of the Dorpat (Tartu) Observatory in Estonia, succeeding Friedrich Wilhelm Struve who had moved to Pulkovo Observatory. He carried out meteorological as well as astronomical observations. He continued Struve's observations of double stars. He remained in Tartu until he retired in 1865, and then returned to Germany.