The Observers of the Moon

The first observer of the moon was Galileo. His poor telescope only magnified thirty times. Nevertheless, in the spots that pitted the lunar disc “like eyes in a peacock's tail,” he was the first to recognise mountains, and measure some heights to which he attributed, exaggerating, an elevation equal to the 20th of the diameter of the disc, or 8,000 metres. Galileo drew up no map of his observations.

A few years later an astronomer of Dantzig, Hevelius - by operations which were only exact twice a month, at the first and second quadrature-reduced Galileo's heights to one-twenty-sixth only of the lunar diameter. This was an exaggeration the other way. But it is to this savant that the first map of the moon is due. The light round spots there form circular mountains, and the dark spots indicate vast seas which, in reality, are plains. To these mountains and extents of sea he gave terrestrial denominations. There is a Sinai in the middle of an Arabia, Etna in the centre of Sicily, the Alps, Apennines, Carpathians, the Mediterranean, the Black Sea, the Caspian, &c.-names badly applied, for neither mountains nor seas recalled the configuration of their namesakes on the globe. That large white spot, joined on the south to vaster continents and terminated in a point, could hardly be recognised as the inverted image of the Indian Peninsula, the Bay of Bengal, and Cochin-China. So these names were not kept. Another chartographer, knowing human nature better, proposed a fresh nomenclature, which human vanity made haste to adopt.

This observer was Father Riccioli, a contemporary of Hevelius. He drew up a rough map full of errors. But he gave to the lunar mountains the names of great men of antiquity and savants of his own epoch.