What, then, was the object to which the original description applied? An object, I should think, far more important than a warrior’s shield. I imagine that anyone who should read the description without being aware of its accepted interpretation, would consider that the poet was dealing with an important series of religious sculptures, possibly that he was describing the dome of a temple adorned with celestial and terrestrial symbols.
In Egypt there are temples of a vast antiquity, having a dome, on which a zodiac—or, more correctly, a celestial hemisphere—is sculptured with constellation-figures. And we now learn, from ancient Babylonian and Assyrian sculptures, that these Egyptian zodiacs are in all probability merely copies (more or less perfect) of yet more ancient Chaldæan zodiacs. One of these Babylonian sculptures is figured in Rawlinson’s ‘Ancient Monarchies.’ It seems probable that in a country where Sabæanism, or star-worship, was the prevailing form of religion, yet more imposing proportions would be given to such zodiacs than in Egypt.
My theory, then, respecting the shield of Achilles is this—
I conceive that Homer, in his eastern travels, visited imposing temples devoted to astronomical observation and star-worship; and that nearly every line in both ‘shields’ is borrowed from a poem in which he described a temple of this sort, its domed zodiac, and those illustrations of the labours of different seasons and of military or judicial procedures which the astrological proclivities of star-worshippers led them to associate with the different constellations.
I think there are arguments of some force to be urged in support of this theory, fanciful as it may seem at a first view.
In the first place, it is necessary that the constellations recognised in Homer’s time (not necessarily, or probably, by Homer) should be distinguished from later inventions.
Aratus, writing long after Homer’s date, mentions forty-five constellations. These were probably derived, without exception, from the globe of Eudoxus. Remembering the tendency which astronomers have shown, in all ages, to add to the list of constellations, we may assume that in Homer’s time the number was smaller. Probably there were some fifteen northern and ten southern constellations, besides the twelve zodiacal signs. The smaller constellations mentioned by Aratus doubtless formed parts of larger figures. Anyone who studies the heavens will recognise the fact that the larger constellations have been robbed of their just proportions to form the smaller asterisms. Corona Borealis was the right arm of Bootes, Ursa Minor was a wing of Draco (now wingless, and no longer a dragon), and so on.
Secondly, it is necessary that the actual appearance of the heavens, with reference to the position of the pole in Homer’s time should be indicated. For my present purpose, it is not necessary that we should know the exact date at which the most ancient of the zodiac-temples were constructed (or to which they were made to correspond). There are good reasons, though this is not the proper place for dwelling upon them, for supposing that the great epoch of reference amongst ancient astronomers preceded the Christian era by about 2200 years. Be this as it may, any epoch between the date named and the probable date at which Homer flourished—say nine or ten centuries before the Christian era—will serve equally well for my present purpose. Now if the effects of equinoctial precession be traced back to such a date, we are led to notice two singular and not uninteresting circumstances. First, the pole of the heavens fell in the central part of the great constellation Draco; and, secondly, the equator fell along the length of the great sea-serpent Hydra, in one part of its course, and elsewhere to the north of all the ancient aquatic constellations,[21] save that one-half of the northernmost fish (of the zodiac pair) lay north of the equator. Thus, if a celestial sphere were constructed with the equator in a horizontal position, the Dragon would be at the summit, Hydra would be extended horizontally along the equator—but with his head and neck reared above that circle—and Argo, Cetus, Capricornus, Piscis Australis, and Pisces—save one-half of the northernmost—would lie below the equator. It may also be mentioned that all the bird-constellations were then, as now, clustered together not far from the equator—Cygnus (the farthest from the equator) being ten degrees or so nearer to that circle than at present.
Now let us turn to the two ‘shields,’ and see whether there is anything to connect them with zodiac-temples, or to remind us of the relations exhibited above. To commence with the ‘Shield of Achilles,’ the opening lines inform us that the shield showed—
The starry lights that heav’n’s high convex crown’d,