When we look upon the multitude of heavenly bodies with which the celestial vault is strewed, our attention is naturally arrested by certain groupings of brilliant stars, apparently associated together on account of their great proximity; and also by certain remarkable single stars which have excessive brilliancy or are completely isolated from the rest. These natural groups seem to have some obscure connection with or dependence on each other. They have always been noticed, even by the most savage races. The languages of several such races contain different names for the same identical groups, and these names, mostly borrowed from terrestrial beings, give an imaginary life to the solitude and silence of the skies. A celestial globe, as we know, presents us with a singular menagerie, rich in curious monsters placed in inconceivable positions. How these constellations, as they are called, were first invented, and by whom, is an interesting question which by the aid of comparative philology we must endeavour now to answer.
Among these constellations there are twelve which have a more than ordinary importance, and to which more attention has always been paid. They are those through which the sun appears to pass in his annual journey round the ecliptic, entering one region each month. At least, this is what they were when first invented. They were called the zodiacal constellations or signs of the zodiac—the name being derived from their being mostly named after living beasts. In our own days the zodiacal constellations are no longer the signs of the zodiac. When they were arranged the sun entered each one on a certain date. He now is no longer at the same point in the heavens at that date, nevertheless he is still said to enter the same sign of the zodiac—which therefore no longer coincides with the zodiacal constellation it was named from—but merely stands for a certain twelfth part of the ecliptic, which varies from time to time. It will be of course of great interest to discover the origin of these particular constellations, the date of their invention, &c.; and we shall hope to do so after having discussed the origin of those seen in the Northern hemisphere which may be more familiar even than those.
We have represented in the frontispiece the two halves of the Grecian celestial sphere—the Northern and the Southern, with the various constellations they contain. This sphere was not invented by the Greeks, but was received by them from more ancient peoples, and corrected and augmented. It was used by Hipparchus two thousand years ago; and Ptolemy has given us a description of it. It contained 48 constellations, of which 21 belonged to the Northern, 15 to the Southern hemisphere, and the remaining twelve were those of the zodiac, situated along the ecliptic.
The constellations reckoned by Ptolemy contained altogether 1,026 stars, whose relative positions were determined by Hipparchus; with reference to which accomplishment Pliny says, "Hipparchus, with a height of audacity too great even for a god, has ventured to transmit to posterity the number of the stars!"
Ptolemy's catalogue contains:—
| For the northern constellations | 361 stars |
| For the zodiacal | 350 " |
| For the southern | 318 " |
| or | ——— |
| For all the 48 constellations | 1,029 " |
| or, since 3 of these are named twice | 1,026 " |
Of course this number is not to be supposed to represent the whole of the stars visible even to the naked eye; there are twice as many in the Northern hemisphere alone, while there are about 5,000 in the whole sky. The number visible in a telescope completely dwarfs this, so that more than 300,000 are now catalogued; while the number visible in a large telescope may be reckoned at not less than 77 millions. The principal northern constellations named by Ptolemy are contained in the following list, with the stars of the first magnitude that occur in each:—
The Great Bear, or David's Chariot, near the centre.
The Little Bear, with the Pole Star at the end of the tail.
The Dragon.
Cepheus, situated to the right of the Pole.
The Herdsman, or the Keeper of the Bear, with the star Arcturus.
The Northern Crown to the right.
Hercules, or the Man who Kneels.
The Lyre, or Falling Vulture, with the beautiful star Vega.
The Swan, or Bird, or Cross.
Cassiopeia, or the Chair, or the Throne.
Perseus.
The Carter, or the Charioteer, with Capella Ophiuchus, or Serpentarius, or Esculapius.
The Serpent.
The Bow and Arrow, or the Dart.
The Eagle, or the Flying Vulture, with Altaïr.
The Dolphin.
The Little Horse, or the Bust of the Horse.
Pegasus, or the Winged Horse, or the Great Cross.
Andromeda, or the Woman with the Girdle.
The Northern Triangle, or the Delta.
The fifteen constellations on the south of the ecliptic were:—
The Whale.
Orion, with the beautiful stars Rigel and Betelgeuse.
The River Endanus, or the River Orion, with the brilliant Achernar.
The Hare.
The Great Dog, with the magnificent Sirius.
The Little Dog, or the Dog which runs before, with Procyon.
The ship Argo, with its fine Alpha (Canopus) and Eta.
The Female Hydra, or the Water Snake.
The Cup, or the Urn, or the Vase.
The Raven.
The Altar, or the Perfuming Pot.
The Centaur, whose star Alpha is the nearest to the earth.
The Wolf, or the Centaur's Lance, or the Panther, or the Beast.
The Southern Crown, or the Wand of Mercury, or Uraniscus.
The Southern Fish, with Fomalhaut.
The twelve zodiacal constellations, which are of more importance than the rest, are generally named in the order in which the sun passes through them in its passage along the ecliptic, and both Latins and English have endeavoured to impress their names on the vulgar by embodying them in verses. The poet Ausonius thus catalogues them:—
"Sunt: Aries, Taurus, Gemini, Cancer, Leo, Virgo,
Libraque, Scorpius, Arcitenens, Caper, Amphora, Pisces."
and the English effusion is as follows:—
"The Ram, the Bull, the Heavenly Twins,
And next the Crab the Lion shines,
The Virgin and the Scales.
The Scorpion, Archer, and He Goat,
The Man that holds the watering-pot,
And Fish with glittering scales."
These twelve have hieroglyphics assigned to them, by which they are referred to in calendars and astronomical works, some of the marks being easily traced to their origin.