This latter type may be found several times repeated in a relief representing a city of Susiana (Vol. I., Fig. 157). Here nearly every house has a tower at one end of its flat roof. Was this a defence, like the towers in the old Italian towns and in the Greek villages of Crete and Magnesia? We do not think so. The social conditions were very different from those of the turbulent republics of Italy, where the populace was divided into hostile factions, or of those mountainous districts whose Greek inhabitants live in constant fear of attack from the Turks who dwell in the plains. The all-powerful despots of Assyria would allow no intestine quarrels, and for the repulse of a foreign enemy, the cities relied upon their high and solid lines of circumvallation. We think that the towers upon the roofs were true belvederes, contrivances to get more air and a wider view; also, perhaps, to allow the inhabitants to escape the mosquitoes by rising well above the highest level reached by the flight of those tiny pests. It was, then, between these two types, as Strabo tells us, that the civil buildings of Mesopotamia were divided. They all had thick terraced roofs but some were domical and others flat.[58] At Mugheir Mr. Taylor cleared the remains of a small house planned on the lines of an irregular cross; it was built of burnt brick and paved with the same material. In the interior the faces of the bricks were covered with a thin and not very adhesive glaze. Two of the doors were round-headed; the arches being composed of bricks specially moulded in the shape of voussoirs; but the numerous fragments of carbonized palm-wood beams which were found upon the floors of each room, showed that the building had been covered with a flat timber roof and a thick bed of earth. Strabo justly observes that the earth was necessary to protect the inmates of the house against the heats of summer. As a rule houses must have been very low. It was only in large towns such as Babylon, that they had three or four stories.[59] * * * * * We need say no more. We have studied the palace in detail, and the palace was only an enlarged, a more richly illustrated edition of the house. It supplied the same wants, but on a wider scale than was necessary in the dwelling of a private individual. To complete our study of civil architecture it is only necessary to give some idea of the fashion in which palaces and houses were grouped into cities, and of the means chosen for securing those cities against hostile assault. § 4. _Towns and their Defences._