Our next post features the map Tabula Selenographica in qua Lunarium Macularum exacta Descriptio, a decorative map of the moon’s surface by Johanna Gabriel Doppelmayr. This copperplate engraving was published by the Homann Heirs in Nuremberg, c.1742. In beautiful, original hand coloring, this double hemispheric map provides a comparative analysis of the topographical information and nomenclature used by two different astronomers- Riccioli and Hevelius. The map also features lunar phases on the four outside corners, as well as a plan of lunar phases around a single point, oriented in between the two hemispheres. Along the top, Doppelmayr engraved a cherub using a telescope and the goddess figure Diana, lady of the moon. This embellishment is a beautiful celebration of the mystery and mythology of the planets, and serves as a contrast to the scientific technical precision used to map the moon’s surface.
The left hemisphere of Tabula Selenographica depicts the lunar map according to Johannes Hevelius, a brewer from Gdansk, whose Selenographica was the first treatises devoted entirely to the moon. This map showed all features of the moon equally – a composite view that showed the Moon in a way that it never appeared in reality, but had accurate placement of the moon’s surface features. The founder of selenography (named after Selene, the goddess of the moon), Hevelius’ nomenclature was always based on earthly features. This nomenclature was used by all Protestant countries until the eighteen century, when it was replaced by a naming system published in 1651 by Jesuit astronomer Giovanni Battista Riccioli.
Riccioli’s lunar maps are referenced in the right hemisphere of Tabula Selenographica. In contrast to the maps of Hevelius, Riccioli gave the large naked-eye spots of the moon names of seas (Sea of Tranquility, Sea of Storm) and the telescopic spots ( what we now call craters) the names of philosophers and astronomers. The Riccioli moon map is historically of great importance, as it is the basis for all lunar nomenclature still in use. Thus, Mare Tranquillitatis, located on this map and named in 1651 by Riccioli, is the same Sea of Tranquility traversed by the Apollo 11 astronauts in 1969.
This map by Doppelmayr compares these two contrasting lunar representations with great detail and expertise. Doppelmayr, 1677-1750, was a mathematician and student of physics and astronomy. A professor, he wrote many works on astronomy, geography, cartography, as well as designed sundials, mathematical instruments, and the first celestial globes.
He often collaborated with cartographer Johanna Baptist Homann, a former Dominican monk and founder of one of the most influential cartographic publishing firms. After Johann’s death, his cartographic business was continued by his son, and later his friend and stepsister’s husband, under the name of Homann Heirs. It was the Homann Heirs who published Doppelmayr’s best-known astronomical work- his Atlas Coelestis– in 1742. This atlas is a collection of the majority of Doppelmayr’s astronomical and cosmographical plates, which he prepared over the years for the Homann publishing firm. Tabula Selenographica is plate 11 in the atlas, and is a variation of a plate that was previously published in Homann’s first atlas, the Neuer Atlas of 1707.
Doppelmayr’s achievements have been celebrated both during and after his life. He was elected a member of several scientific societies, including the Berlin Academy of Sciences, the Royal Society of London, and St. Petersburg Academy of Sciences. The lunar crater Doppelmayr, the nearby rille (lunar channel) Rimae Doppelmayr, and a minor planet 12622 Doppelmayr are all named in his honor.