A division of buildings into such great series as these cannot, however, supersede the more obvious historical and geographical divisions. The architecture of every ancient country was partly the growth of the soil, _i.e._ adapted to the climate of the country, and the materials found there, and partly the outcome of the national character of its inhabitants, and of such influences as race, colonisation, commerce, or conquest brought to bear upon them. These influences produced strong distinctions between the work of different peoples, especially before the era of the Roman Empire. Since that period of universal dominion all buildings and styles have been influenced more or less by Roman art. We accordingly find the buildings of the most ancient nations separated from each other by strongly marked lines of demarcation, but those since the era of the Empire showing a considerable resemblance to one another. The circumstance that the remains of those buildings only which received the greatest possible attention from their builders have come down to us from any remote antiquity, has perhaps served to accentuate the differences between different styles, for these foremost buildings were not intended to serve the same purpose in all countries. Nothing but tombs and temples have survived in Egypt. Palaces only have been rescued from the decay of Assyrian and Persian cities; and temples, theatres, and places of public assembly are the chief, almost the only remains of architecture in Greece. A strong contrast between the buildings of different ancient nations rises also from the differing point of view for which they were designed. Thus, in the tombs and, to a large extent, the temples of the Egyptians, we find structures chiefly planned for internal effect; that is to say, intended to be seen by those admitted to the sacred precincts, but only to a limited extent appealing to the admiration of those outside. The buildings of the Greeks, on the other hand, were chiefly designed to please those who examined them from without, and though no doubt some of them, the theatres especially, were from their very nature planned for interior effect, by far the greatest works which Greek art produced were the exteriors of the temples. [Illustration: FIG. 5.--PART OF THE EXTERIOR OF THE COLOSSEUM, ROME. (NOW IN RUINS.)]