Page:EB1911 - Volume 07.djvu/25

 concentric annuli, the northern ones in an inner annulus subdivided into 60 degrees, the zodiacal ones into a medial annulus of 120 degrees, and the southern ones into an outer annulus of 240 degrees. Brown has suggested a correlation of the Euphratean names with those of the Greeks and moderns. His results may be exhibited in the following form:—the central line gives the modern equivalents of the names in the Euphratean zodiac; the upper line the modern equivalents of the northern paranatellons; and the lower line those of the southern paranatellons. The zodiacal constellations have an interest peculiarly their own; placed in or about the plane of the ecliptic, their rising and setting with the sun was observed with relation to weather changes and the more general subject of chronology, the twelve subdivisions of the year being correlated with the twelve divisions of the ecliptic (see ).

The Phoenicians—a race dominated by the spirit of commercial enterprise—appear to have studied the stars more especially with respect to their service to navigators; according to Homer “the stars were sent by Zeus as portents for mariners.” But all their truly astronomical writings are lost, and only by a somewhat speculative piecing together of scattered evidences can an estimate of their knowledge be formed. The inter-relations of the Phoenicians with the early Hellenes were frequent and far-reaching, and in the Greek presentation of the legends concerning constellations a distinct Phoenician, and in turn Euphratean, element appears. One of the earliest examples of Greek literature extant, the Theogonia of Hesiod (c. 800 ), appears to be a curious blending of Hellenic and Phoenician thought. Although not an astronomical work, several constellation subjects are introduced. In the same author’s Works and Days, a treatise which is a sort of shepherd’s calendar, there are distinct references to the Pleiades, Hyades, Orion, Sirius and Arcturus. It cannot be argued, however, that these were the only stars and constellations named in his time; the omission proves nothing. The same is true of the Homeric epics wherein the Pleiades, Hyades, Ursa major, Orion and Boötes are mentioned, and also of the stars and constellations mentioned in Job. Further support is given to the view that, in the main, the constellations were transmitted to the Greeks by the Phoenicians from Euphratean sources in the fact that Thales, the earliest Greek astronomer of any note, was of Phoenician descent. According to Callimachus he taught the Greeks to steer by Ursa minor instead of Ursa major; and other astronomical observations are assigned to him. But his writings are lost, as is also the case with those of Phocus the Samian, and the history of astronomy by Eudemus, the pupil of Aristotle; hence the paucity of our knowledge of Thales’s astronomical learning.

From the 6th century onwards, legends concerning the constellation subjects were frequently treated by the historians and poets. Aglaosthenes or Agaosthenes, an early writer, knew Ursa minor as , Cynosura, and recorded the translation of Aquila; Epimenides the Cretan (c. 600 ) recorded the translation of Capricornus and the star Capella; Pherecydes of Athens (c. 500–450 ) recorded the legend of Orion, and stated the astronomical fact that when Orion sets Scorpio rises; Aeschylus (525–456 ) and Hellanicus of Mytilene (c. 496–411 ) narrate the legend of the seven Pleiades—the daughters of Atlas; and the latter states that the Hyades are named either from their orientation, which resembles (upsilon), “or because at their rising or setting Zeus rains”; and Hecataeus of Miletus (c. 470 ) treated the legend of the Hydra.

In the 5th century the Athenian astronomer Euctemon, according to Geminus of Rhodes, compiled a weather calendar in which Aquarius, Aquila, Canis major, Corona, Cygnus, Delphinus, Lyra, Orion, Pegasus, Sagitta and the asterisms Hyades and Pleiades are mentioned, always, however, in relation to weather changes. The earliest Greek work which purported to treat the constellations qua constellations, of which we have certain knowledge, is the  of Eudoxus of Cnidus (c. 403–350 ). The original is lost, but a versification by Aratus (c. 270 ), a poet at the court of Antigonus Gonatas, king of Macedonia, and an  or commentary by Hipparchus, are extant. In the  of Aratus 44 constellations are enumerated, viz. 19 northern:—Ursa major, Ursa minor, Boötes, Draco, Cepheus, Cassiopeia, Andromeda, Perseus, Triangulum, Pegasus, Delphinus, Auriga, Hercules, Lyra, Cygnus, Aquila, Sagitta, Corona and Serpentarius; 13 central or zodiacal:—Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricornus, Aquarius, Pisces and the Pleiades; and 12 southern:—Orion, Canis, Lepus, Argo, Cetus, Eridanus, Piscis australis, Ara, Centaurus, Hydra, Crater and Corvus. In this enumeration Serpens is included in Serpentarius and Lupus in Centaurus; these two constellations were separated by Hipparchus and, later, by Ptolemy. On the other hand, Aratus kept the Pleiades distinct from Taurus, but Hipparchus reduced these stars to an asterism. Aratus was no astronomer, while Hipparchus was; and from the fact that the latter adopted, with but trifling exceptions, the constellation system portrayed by Aratus, it may be concluded that the system was already familiar in Greek thought. And three hundred years after Hipparchus, the Alexandrian astronomer Ptolemy adopted a very similar scheme in his uranometria, which appears in the seventh and eighth books of his Almagest, the catalogue being styled the  or “accepted version.”

The Almagest has a dual interest: first, being the work of one primarily a commentator, it presents a crystallized epitome of all earlier knowledge; and secondly, it has served as a basis of subsequent star-catalogues. The Ptolemaic catalogue embraces only those stars which were visible at Rhodes in the time of Hipparchus (c. 150 ), the results being corrected for precession “by increasing the longitudes by 2° 40′, and leaving the latitudes undisturbed” (Francis Baily, Mem. R.A.S., 1843). The names and orientation of the constellations therein adopted are, with but few exceptions, identical with those used at the present day; and as it cannot be doubted that Ptolemy made only very few modifications in the system of Hipparchus, the names were adopted at least three centuries before the Almagest was compiled. The names in which Ptolemy differs from modern usage are:—Hercules ( ), Cygnus ( ), Eridanus ( ), Lupus ( ), Pegasus ( ), Equuleus ( ), Canis minor ( ), and Libra ( ), although  is used for the same constellation in other parts of the Almagest). The following table gives the names of the constellations as they occur in (1) modern catalogues; (2) Ptolemy ( 150); (3) Ulugh Beg (1437); (4) Tycho Brahe (1628); the last column gives the English equivalent of the modern name.

The reverence and authority which was accorded the famous compilation of the Alexandrian astronomer is well evidenced by the catalogue of the Tatar Ulugh Beg, the Arabian names there adopted being equivalent to the Ptolemaic names in nearly every case; this is also shown in the Latin translations given below. Tycho Brahe, when compiling his catalogue of stars, was unable to observe Lupus, Ara, Corona australis and Piscis australis, on account of the latitude of Uranienburg; and hence these constellations are omitted from his catalogue. He diverged from Ptolemy when he placed the asterisms Coma Berenices and Antinous upon the level of formal constellations, Ptolemy having<section end="Constellation" />