The question whether the Gegenschein can be accounted for by the reflection of light from the same matter as the zodiacal band is still unsettled.
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.
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.
3 No representation of the seventh sign has yet been discovered on any Euphratean monument; but it is noticeable that the eighth is frequently doubled,4 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.
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 €corpion.
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 cyclical meaning of the succession of zodiacal signs, though now obscured by interpolations and substitutions, was probably once clear and entire.
The eleventh tablet narrates the deluge; the twelfth associates the apotheosis of Eabani with the zodiacal emblems of the resurrection.
The native Chinese zodiacal system was of unexampled complexity.
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.6 The Aztec calendar dated from the 7th century; but the zodiacal tradition embodied by it was doubtless much more ancient.
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 are invariably twenty-seven.
The arrangement would have been correct about 2300 B.C.; it would scarcely have been possible after 1800 B.C. 3 We find nowhere else a well-authenticated zodiacal sequence corresponding to so early a date.
The correspondence does not, however, extend to the stars; and some coincidences adverted to by Humboldt between the nakshatras and the zodiacal animals of Central Asia are of the same nominal character.
The Hindu zodiacal constellations belong then to an earlier epoch than the Chinese " stations," such as they have been transmitted to our acquaintance.
Euphratean exploration has so far brought to light no traces of ecliptical partition by the moon's diurnal motion, unless, indeed, zodiacal associations be claimed for a set of twenty-eight deprecatory formulae against evil spirits inscribed on a Ninevite tablet.4 The safest general conclusions regarding this disputed subject appear to be that the sieu, distinctively and unvaryingly Chinese, cannot properly be described as divisions of a lunar zodiac, that the nakshatras, though of purely Indian origin, became modified by the successive adoption of Greek and Chinese rectifications and supposed improvements; while the manazil constituted a frankly eclectic system, in which elements from all quarters were combined.
7 The " power of the signs " was similarly distributed among the parts of the human body: Et quanquam communis eat tutela per omne Corpus, et in proprium divisis artubus exit: Namque aries capiti, taurus cervicibus haeret; Brachia sub geminis censentur, pectora cancro.8 Warnings were uttered against surgical treatment of a member through whose sign the moon happened to be passing; 9 and zodiacal anatomy was an indispensable branch of the healing art in the Middle Ages.
10 Individuals, too, adopted zodiacal emblems. Capricornus was impressed upon the coins of Augustus, Libra on those ' of Pythodoris, queen of Pontus; a sultan of Iconium displayed Leo as his " horoscope " and mark of sovereignty; Stephen of England chose the protection of Sagittarius.
They were called the " media of the whole circle of the zodiac "; 11 each ten-day period of the Egyptian year was consecrated to the decanal god whose section of the ecliptic rose at its commencement; the body was correspondingly apportioned, and disease was cured by invoking the zodiacal regent of the part affected.
Probably the most ancient zodiacal representation in existence is a fragment of a Chaldaean planisphere in the British Museum, once inscribed with the names of the twelve months and their governing signs.
In the zodiac of Merton College, Oxford, Libra is represented by a judge in his robes and Pisces by the dolphin of Fitzjames, warden of the college, 1482-1507.6 The great rose-windows of the Early Gothic period were frequently painted with zodiacal emblems; and some frescoes in the cathedral of Cologne contain the signs, each with an attendant angel, just as they were depicted on the vault of the church at Mount Athos.
Zodiacal Light >>
He calculated an orbit for the comet of 1 759 (Halley's), reduced Lacaille's observations of 515 zodiacal stars, and was, in 1763, elected a member of the Academy of Sciences.
He was the first, in 1867, to examine the spectrum of the aurora borealis, and detected and measured the characteristic bright line in its yellow green region; but he was mistaken in supposing that this same line, which is often called by his name, is also to be seen in the zodiacal light.
It contains an easy and accurate method for calculating eclipses; an essay on colour, in which three primary colours are recognized; a catalogue of 998 zodiacal stars; and a memoir, the earliest of any real value, on the proper motion of eighty stars, originally communicated to the Gottingen Royal Society in 1760.
The zodiacal signs were not introduced till the Ptolemaic period.
Finally there is the envelope of still vaster extent and of unknown constitution which gives the zodiacal light; its greatest extent is along the ecliptic, but it can also be certainly traced for 35° in a perpendicular direction.
In diameter; he substituted equatorial for zodiacal armillae, thus definitively establishing the system of measurements in right ascension and declination; and improved the graduation of circular arcs by adopting the method of " transversals."
Tobias Mayer of GÃ¶ttingen (1723-1762) originated the mode of adjusting transit-instruments still in vogue; drew up a catalogue of nearly a thousand zodiacal stars (published posthumously in 1775); and deduced the proper motions of eighty stars from a comparison of their places as given by Olaus Romer in 1706 with those obtained by himself in 1756.
ZODIACAL LIGHT, a faint illumination of the sky, surrounding the sun and elongated in the direction of the ecliptic on each side of the sun.
P. 136, where a useful sketch of the general results of zodiacal research will be found.
The only source of doubt as to the validity of the conclusion that this is really the zodiacal light arises from the possibility that, after the close of the ordinarily recognized twilight, there may be a faint illumination arising from the reflection of light by the very rare upper atmosphere, shown by the phenomena of meteors to extend some hundred miles or more above the earth's surface.
Of great importance is the Creation Legend, a cuneiform compiled from older records during the reign of Assur-bani-pal, c. 650 B.C., in which there occurs a passage interpretable as pointing to the acceptance of 36 constellations: 12 northern, 12 zodiacal and 12 southern.
These constellations were arranged in three concentric annuli, the northern ones in an inner annulus subdivided into 60 degrees, the zodiacal ones into a medial annulus of 1 zo degrees, and the southern ones into an outer annulus of 240 degrees.
19 northern: - Ursa major, Ursa minor, Bootes, 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 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."
The problem of separating a possible effect produced in this way from the zodiacal light proper may seem to offer some difficulty.
But the few observations made show that, after ordinary twilight has ended in the evening, the northern base of the zodiacal light extends more and more toward the north as the hours pass until, towards midnight, it merges into the light of the sky described by the two observers mentioned.
Since the tenuous edge of the lens extends beyond the earth's orbit it follows that there must be some zodiacal light, whether it can be seen or not, passing entirely across the sky, along or near the ecliptic. Observations of this zodiacal band are therefore of great interest.
Intimately connected with this band and with the zodiacal light is the Gegenschein, or counter-glow, a faint illumination of the sky in the region opposite the sun, which may generally be seen by a trained eye when all the conditions are favourable., Unfavourable conditions are moonlight, nearness to the Milky Way, and elevation of the light above the horizon (and therefore a depression of the sun below the horizon) of less than 20°, and the presence in the region of any bright planet.
From what has been said of its position it is evident that the zodiacal band, when seen across the sky, must include it.
From the description given of the zodiacal band and the Gegenschein, it is clear that these objects should be best seen at the highest elevation, especially within the tropics.
He saw the zodiacal band at midnight as a complete arch spanning the sky, agreeing in this point with the observations of Barnard.
It has even been said that observers at great elevations have failed to see the zodiacal light; but it is scarcely credible that this failure could arise from any other cause than not knowing what it was or where to look for it.