ZODIAC (O CoAtaK()3 K-olCA03, from (.68cov, "a little animal "), an imaginary zone of the heavens within which lie the paths of the sun, moon, and principal planets. It is bounded by two circles equidistant from the ecliptic, about eighteen degrees apart ; and it is divided into twelve signs, and marked by twelve constellations. The signs - the Greek 8w8cKccrwipta - are geometrical divisions thirty degrees in extent, counted from the spring equinox in the direction of the sun's progress through them. The whole series accordingly shifts westward through the effect of precession by about one degree in seventy-two years. At the moment of crossing the equator towards the north the sun is said to be at the first point of Aries ; some thirty days later it enters Taurus, and so on through Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricornus, Aquarius, and Pisces (see ASTRONOMY, vol. ii. p. 771). The constellations bearing the same names coincided approximately in position, when Hipparchus observed them at Rhodes, with the divisions they designate. The discrepancy now, however, amounts to the entire breadth of a sign, the sun's path in Aries lying among the stars of Pisces, in Taurus among those of Aries, &c.
The twelvefold division of the zodiac was evidently suggested by the occurrence of twelve full moons in successive parts of it in the course of each year. This approximate relation was first systematically developed by the early inhabitants of Mesopotamia, and formed the starting-point for all their divisions of time. As the year separated, as it were of itself, into twelve months, so the day was divided into twelve "double hours," and the great cosmical period of 43,200 years into twelve " sars." Each sar, month, and hour was represented at once visibly and symbolically by a twelfth part of the " furrow " drawn by the solar Bull across the heavens. The idea of tracing the sun's path among the stars was, when it occurred to Chaldean astronomers, an original and, relatively to their means, a recondite one. We owe to its realization by them the constitution and nomenclature of the twelve signs of the zodiac. Assyrian cylinders and inscriptions indicate for the familiar series of our text-books an antiquity of some four thousand years. Ages before Asurbanipal reigned at Nineveh the eighth month (Marchesvan) was known as " the month of the star of the Scorpion," the tenth (Tebet) belonged to the "star of the Goat," the twelfth (Adar) to the " star of the Fish of Hea."1 The motive underlying the choice of symbols is in a few cases obvious, but in most remains conjectural. The attributes of the deities appointed to preside over the months and signs were to some extent influential. Two of them, indeed, took direct possession of their respective portions of the sky. The zodiacal Virgo is held to represent the Assyrian Venus, Ishtar, the ruling divinity of the sixth month, and Sagittarius the archer-god Nergal, to whom the ninth month was dedicated. But no uniform system of selection was pursued ; or rather perhaps the results of several, adopted at various epochs, and under the influence of varying currents of ideas, became amalgamated in the final series.
This, there is reason to believe, was the upshot of a prehistoric reform. So far as positive records go, Aries was always the first sign. But the arrangement is, on the face of it, a comparatively modern one. None of the brighter stars of the constellation could be said even roughly to mark the equinox much before 1800 B.C. ; during a long stretch of previous time the leading position belonged to the stars of Taurus.2 Numerous indications accordingly point to a corresponding primitive zodiac. Setting aside as doubtful evidence derived from interpretations of cuneiform inscriptions, we meet, in connexion with Mithraic and Mylittic legends, reminiscences of a zodiac and religious calendar in which the Bull led the way.3 Virgil's Candidus auratis aperit cum cornibus annum perpetuates the tradition. And we shall see presently that the Pleiades, not only were originally, but continued to be until well within historical memory, the first asterism of the lunar zodiac.
In the Chalthean signs fragments of several distinct strata of thought appear to be embedded. From one point of view, they shadow out the great epic of the destinies of the human race ; again, the universal solar myth claims a • share in them ; hoary traditions were brought into ex post facto connexion with them ; or they served to commemorate simple meteorological and astronomical facts.
The first Babylonian month Nisan, dedicated to Anu and Bel, was that of " sacrifice "; and its association with the Ram as the chief primitive object of sacrifice is thus intelligible.4 According to an alternative explanation, however, the heavenly Ram, placed as leader in front of the flock of the stars, merely embodied a spontaneous figure of the popular imagination. An antique persuasion, that the grand cycle of creation opened under the first sign, has been transmitted to modern cognizance by Dante (Inf., i. 38). The human race, on the other hand, was supposed to have come into being under Taurus. The solar interpretation of the sign goes back to the far-off time when the year began with Taurus, and the sun was conceived of as a bull entering upon de great furrow of heaven as he ploughed his way among the stars. In the third month' and sign the building of the first city and the fratricidal brothers - the Romulus and Remus of Roman legend - were brought to mind. The appropriate symbol was at first indifferently a pile of bricks or two male children, always on early monuments placed feet to feet. The retrograde movement of a crab typified, by an easy association of ideas, the retreat of the sun from his farthest northern excursion, and Cancer was constituted the sign of the summer solstice. The Lion, as the symbol of fire, repre rented the culmination of the solar heat. In the sixth month, the descent of Ishtar to Hades in search of her lost husband Tammuz was celebrated, and the sign of the Virgin had thus a purely mythological signification.
The history of the seventh sign is somewhat complicated. • The earlier Greek writers, - Eudoxus, Eratosthenes,Hipparchus, - knew of only eleven zodiacal symbols, but made one do double duty, extending the Scorpion across the seventh and eighth •divisions. The Balance, obviously indicating the equality of day and night, is first mentioned as the sign of the autumnal equinox by Geminus and Varro, and obtained, through Sosigenes of Alexandria, official recognition in the Julian calendar. Nevertheless, Virgil (Georg., i. 32) regarded the space it presided over as so much waste land, provisionally occupied by the " Claws " of the Scorpion, but readily available for the apotheosis of Augustus. Libra was not of Greek invention. Ptolemy, who himself chiefly used the " Claws " (XriXai), speaks of it as a distinctively Chaldman sign;' and it occurs as an extra-zodiacal asterism in the Chinese sphere. An ancient Chinese law, moreover, prescribed the regularization of weights and measures at the spring equinox.' No representation of the seventh sign has yet been discovered on any Euphratean monument ; but it is noticeable that the eighth is frequently doubled,3 and it is difficult to avoid seeing in the pair of zodiacal scorpions carved on Assyrian cylinders the prototype of the Greek scorpion and claws. Both Libra and the sign it eventually superseded thus owned a Chaldwan birthplace. The struggle of rival systems of nomenclature, from which our zodiacal series resulted, is plainly visible in their alternations ; and the claims of the competing signs were long sought to be conciliated by representing the Balance as held between the claws of the Scorpion.
The definitive decline of the sun's power after the autumnal equinox was typified by placing a Scorpion as the symbol of darkness in the eighth sign. Sagittarius, figured later as a Centaur, stood for the Babylonian Mars. Capricornus, the sign of the winter solstice, is plausibly connected with the caprine nurse of the young solar god in Oriental legends, of which that of Zeus and Amalthea is a variant.4 The fish-tailed Goat of the zodiac presents a close analogy with the Mexican calendar sign Cipactli, a kind of marine monster resembling a narwhal.' Aquarius is a still more exclusively meteorological sign than Leo. The eleventh month was known in Euphratean regions as that of "want and rain." The deluge was traditionally associated with it. It was represented in zodiacal symbolism by the god Ramman, crowned with a tiara and pouring water from a vase, or more generally by the vase and water without the god. The resumption of agricultural labours after the deluge was commemorated in the twelfth month, and a mystical association of the fishes, which were its sign, with the life after death is evident in a monument of Assyrian origin described by M. Clermont-Ganneau, showing a corpse guarded by a pair of fish-gods.6 The doubling of the sign of Pisces still recalls, according to Mr Sayce,7 the arrangement of the Babylonian calendar, in which a year of 360 days was supplemented once in six years by a thirteenth month, a second Adar. To the double month corresponded the double sign of the "Fishes of Hea."8 The cyclical meaning of the succession of zodiacal signs, though now obscured by interpolations and substitutions, was probably once clear and entire. It is curiously reflected in the adventures of the Babylonian Hercules, the solar hero Izdubar.9 They were recorded in the comparatively late surviving version of the 7th century n.c., on twelve tablets, with an obvious design of correlation with the twelve divisions of the sun's annual course. Izdubar's conquest of the winged bull Heabani was placed under Taurus; his slaying of the tyrant Houmbaba (the prototype of Geryon) in the fifth month typified the victory of light over darkness, represented in plastic art by the group of a lion killing a bull, which is the form ordinarily given to the sign Leo on Ninevite cylinders.'0 The wooing of Ishtar by the hero of the epic falls under Virgo, and his encounter with two scorpion men, guardians of the rising and the setting sun, under Scorpio. The eleventh tablet narrates the deluge ; the twelfth associates the apotheosis of Heabani (the Babylonian Chiron) with the zodiacal emblems of the resurrection.
In the formation of the constellations of the zodiac very little regard was paid to stellar configurations. The Chaltheans chose three stars in each sign to be the "councillor gods" of the planets.0 These were called by the Greeks "decans," because ten degrees of the ecliptic and ten days of the year were presided over by each. The college of the decans was conceived as moving, by their annual risings and settings, in an "eternal circuit" between the infernal and supernal regions. Our modern asterisms first appear in the Plt&nomena of Eudoxus about 370 B.C. But Eudoxus, there is reason to believe, consulted, not the heavens, but a celestial globe of an anterior epoch, on which the stars and the signs were forced into unnatural agreement. The representation thus handed down to us (in the verses of Aratus) has been thought to tally best with the state of the sky about 2000 n.c.;'2 and the mention of a pole-star, for which Eudoxus was rebuked by Hipparchus, seems, as Mr W. T. Lynn has pointed out," to refer to the time when a Draconis stood near the pole. The data afforded by Eudoxus, however, are far too vague to serve as the basis of any chronological conclusion.
The Egyptians adopted from the Greeks, with considerable modifications of its attendant symbolism, the twelvefold division of the zodiac. Aries became the Fleece; two Sprouting Plants, typifying equality or resemblance, stood for Gemini ; Cancer was re-named Scarabus ; Leo was converted, from the axe-like configuration of its chief stars, into the Knife ; Libra into the Mountain of the Sun, a reminiscence, apparently, of the Euphratean association of the seventh month with a "holy mound," designating the Biblical tower of Babel. A Serpent was the Egyptian equivalent of Scorpio ; the Arrow only of Sagittarius was retained ; Capricornus became "Life," or a Mirror as an image of life; Aquarius survived as Water; Taurus, Virgo, and Pisces remained unchanged." The motive of some of the substitutions was to avoid the confusion which must have ensued from the duplication of previously existing native asterisms ; thus, the Egyptian and Greek Lions were composed of totally different stars. Abstractions in other cases replaced concrete objects, with the general result of effacing the distinctive character of the Greek zodiac as a "circle of living things."
Early Zoroastrian writings, though impregnated with star-worship, show no traces of an attempt to organize the heavenly array. In the Bundehish, however (9th century), the twelve "Akhtirs," designated by the same names as our signs, lead the army of Ormuzd, while the seven "Awakhtfirs " or planets (including a meteor and a comet) fight for Ahriman. The knowledge of the solar zodiac thus turned to account for dualistic purposes was undoubtedly derived from the Greeks. By them, too, it was introduced into Hindustan. Aryabhata, about the beginning of our era, reckoned by the same signs as Hipparchus. They were transmitted from India by Buddhist missionaries to China, but remained in abeyance until the Jesuit reform of Chinese astronomy in the 17th century.
The native zodiacal system was of unexampled complexity. Besides divisions into twenty-eight and twenty-four acquaintance with the signs related only to their secondary function as dies (so to speak) with which to stamp recurring intervals of time.
The synodical revolution of the moon laid down the lunar lines of the solar, its sidereal revolution those of the lunar zodiac. zodiac. The first was a circlet of "full moons"; the second marked the diurnal stages of the lunar progress round the sky, from and back again to any selected star. The moon was the earliest " measurer " both of time and space ; but its services can scarcely have been rendered available until stellar " milestones " were established at suitable points along its path. Such were the Hindu naloshatras, a word Hindu originally signifying stars in general, but appropriated to system designate certain small stellar groups marking the divisions s°hfatnarask-. of the lunar track. They exhibit in an exaggerated form the irregularities of distribution visible in our zodiacal constellations, and present the further anomaly of being frequently reckoned as twenty-eight in number, while the ecliptical arcs they characterize arc invariably twenty-seven. Now, since the moon revolves round the earth in 27k days, hesitation between the two full numbers might easily arise ; yet the real explanation of the difficulty appears to be different. The superfluous asterism, named AbloYit, included the bright star a Lyrae, under whose influence the gods had vanquished the Asuras. Its invocation with the other nakshatras, remoteness from the ecliptic notwithstanding, was thus due (according to Prof. Max ;Miller's plausible conjecture) 6 to its being regarded as of especially good omen. Acquaintance with foreign systems of twenty-eight lunar divisions tended doubtless to fix its position, which remained, nevertheless, always equivocal. Alternately admitted into or rejected from the series, it was finally, some six or seven centuries ago, eliminated by the effects of precession in reversing the order of culmination of its limiting stars.
The notion of a twenty-seven-fold division of the zodiac was deeply rooted in Hindu tradition. The number and the name were in early times almost synonymous. Thus, a nakshatra-mala denoted a necklace of twenty-seven pearls and the fundamental equality of the parts was figured in an ancient legend, by the compulsion laid upon King Soma (the Moon) to share his time impartially between all his wives, the twenty-seven daughters of Prajapati. Everything points to a native origin for the system of nakshatras. Some were named after exclusively Vedic deities ; they formed the basis of the sacrificial calendar of the Brahmans ; the old Indian names of the months were derived from them ; their existence was presupposed in the entire structure of Hindu ritual and science.9 They do not, however, obtain full recognition in Sanskrit literature until the Brahmana period (7th or 8th century n.c.). The Rig-Veda contains only one allusion to them, where it is said that "Soma is placed in the lap of the nakshatras" ; and this is in a part including later interpolations.
Positive proof of the high antiquity of the Hindu lunar zodiac is nevertheless afforded by the undoubted fact that the primitive series opened with Krittika (the Pleiades) as the sign of the vernal equinox. The arrangement would have been correct about 2300 B.C. ; it would scarcely have been possible after 1800 B.c.19 We find nowhere else a well-authenticated zodiacal sequence corresponding to so early a elate. The reform by which Krittika, now relegated to the third place, was superseded as the head of the series by " Agvini "11 was accomplished under Greek parts, it included two distinct duodenary series. The tse or " stations " were referred by Biot to the date 1111 B.c. Measured from the winter solstice of that epoch, they corresponded, in conformity with the Chinese method of observation by intervals of what we now call right ascension, to equal portions of the celestial equator.1 Projected upon the ecliptic, these were, of course, considerably unequal, and the tse accordingly differed essentially from the Chalthean and Greek signs. Their use was chiefly astrological, and their highly figurative names - " Great Splendour," " Immense Void," " Fire of the Phoenix," &c. - had reference to no particular stars. They became virtually merged in the European series, stamped with official recognition upwards of two centuries ago. The twenty-four tsieki or demi-tse were probably invented to mark the course of weather changes throughout the year. Their appellations are purely meteorological.
The characteristic Chinese mode of dividing the "yellow road " of the sun was, however, by the twelve " cyclical animals," - Rat, Ox, Tiger, Hare, Dragon or Crocodile, Serpent, Horse, Sheep, Monkey, Hen, Dog, Pig. The opening sign corresponds to our Aquarius, and it is remarkable that the rat is, in the far East, frequently used as an ideograph for "water." But here the agreement ceases. For the Chinese series has the strange peculiarity of proceeding in a retrograde direction or against the course of the sun. Thus, the second sign (of the Ox) occupies the position of Capricorn, the third that of Sagittarius, and so on. The explanation of this seeming anomaly is to be found in the primitive destination of the " animals " to the purposes of an "horary zodiac." Their succession, established to mark the hours of day and night, was not unnaturally associated with the diurnal revolution of the sphere from east to west.2 They are unquestionably of native origin. Tradition ascribes their invention to Tajao, minister of the emperor Hwang-te, who reigned c. 2697 B.C., and it can scarcely be placed later than the 7th century n.c.3 The Chinese circle of the " animals " obtained early a wide diffusion. It was adopted by Tartars, Turks, and Mongols, in Tibet and Tong-king, Japan and Corea. It is denominated by Humboldt 4 the "zodiac of hunters and shepherds," and he adds that the presence in it of a tiger gives it an exclusively Asiatic character. It appears never to have been designed for astronomical employment. From the first it served to characterize the divisions of time. The nomenclature not only of the hours of the day and of their minutest intervals was supplied by it, but of the months of the year, of the years in the Oriental sixty-year cycle, and of the days in the "little cycle" of twelve clays. Nor has it yet fallen into desuetude. Years "of the Bat," "of the Tiger," "of the Pig," still figure in the almanacs of Central Asia, Cochin China, and Japan.
A large detachment of the "cyclical animals" even found its way to the New World. Seven of the twenty days constituting the Aztec month bore names evidently borrowed from those of the Chinese horary signs. The Hare (or Rabbit), -Monkey, Dog, and Serpent reappeared without change ; for the Tiger, Crocodile, and Hen, unknown in America, the Ocelot, Lizard, and Eagle were substituted as analogous.5 The Aztec calendar dated from the 7th century ; but the zodiacal tradition embodied by it was doubtless much more ancient. Of the zodiac in its true sense of a partitioned belt of the sphere there was no aboriginal knowledge on the American continent. Mexican Blot, Journ. des Set'ans, 1839, p. 729, and 1840, P. 151 ; Gaubil, Mist. de l'Astr. Chinoise, p. 9.
Humboldt, Vue-s des C'orclilleres, p. 168.
Rig-Veda Sunhita, vol. iv., 1862, Preface, p. lxii.
Max Muller, op. cit., p. lxiv. 9 I6id., p. 42.
u A. Weber, Indische Studien, vol. x. p. 241.