Even in the marvellous shield there are other and indirect notes of reality. In speaking of the shield of Achilles, I departed intentionally from [202] the order in which the subjects of the relief are actually introduced in the Iliad, because, just then, I wished the reader to receive the full effect of the variety and elaborateness of the composition, as a representation or picture of the whole of ancient life embraced within the circumference of a shield. But in the order in which Homer actually describes those episodes he is following the method of a very practicable form of composition, and is throughout much closer than we might at first sight suppose to the ancient armourer's proceedings. The shield is formed of five superimposed plates of different metals, each plate of smaller diameter than the one immediately below it, their flat margins showing thus as four concentric stripes or rings of metal, around a sort of boss in the centre, five metals thick, and the outermost circle or ring being the thinnest. To this arrangement the order of Homer's description corresponds. The earth and the heavenly bodies are upon this boss in the centre, like a little distant heaven hung above the broad world, and from this Homer works out, round and round, to the river Oceanus, which forms the border of the whole; the subjects answering to, or supporting each other, in a sort of heraldic order--the city at peace set over against the city besieged- -spring, summer, and autumn balancing each other--quite congruously with a certain heraldic turn common in contemporary Assyrian art, which delights in [203] this sort of conventional spacing out of its various subjects, and especially with some extant metal chargers of Assyrian work, which, like some of the earliest Greek vases with their painted plants and flowers conventionally arranged, illustrate in their humble measure such heraldic grouping.