SELENOGRAPHY

, the description and representation of the moon, with all the parts and appearances of her disc or face; like as geography does those of the earth. |

Since the invention of the telescope, Selenography is very much improved. We have now distinct names for most of the regions, seas, lakes, mountains, &c, visible in the moon's body. Hevelius, a celebrated astronomer of Dantzic, and who published the first Selenography, named the several places of the moon from those of the earth. But Riccioli afterwards called them after the names of the most celebrated astronomers and philosophers. Thus, what the one calls mons Porphyrites, the other calls Aristarchus; what the one calls Ætna, Sinai, Athos, Apenninus, &c, the other calls, Copernicus, Posidonius, Tycho, Gassendus, &c.

M. Cassini has published a work called Instructions Seleniques, and has published the best map of the moon.

SELEUOIDÆ, in Chronology, the era of the Seleucidæ, or the Syro-Macedonian era, which is a computation of time, commencing from the establishment of the Seleucidæ, a race of Greek kings, who reigned as successors of Alexander the Great, in Syria, as the Ptolomies did in Egypt. According to the best accounts, the first year of this era falls in the year 311 before Christ, which was 12 years after the death of Alexander.