We find a still more simple plan upon an Assyrian monument of much later date, namely, upon the armour of beaten bronze that formerly protected the gates of Balawat. In this example (Fig. 154) the doorways, the angles, and the centres of the two longer curtains are strengthened by towers. [Illustration: FIG. 154.--Assyrian plan; from the Balawat gates in the British Museum.] [Illustration: FIG. 155.--Plan and section of a fortress; from Layard.] The way in which the sculptor has endeavoured to suggest the crenellations shows that these plans are not drawn on the same principal as ours; there is no section taken at the junction with the soil or at a determined height; the draughtsman in all probability wished to give an idea of the height of the flanking towers. His representation is an ideal _projection_ similar to those of which we find so many examples in Egypt, only that here we have the towers laid flat outside the fortification to which they belong in such a fashion that their summits are as far as possible from the centre of the structure. We shall see this better in another plan of the same kind in which the details are more carefully made out (Fig. 155). It comes from a bas-relief, on which a circular fortress, divided into four equal parts by walls radiating from its centre, is portrayed. In this relief we find another favourite process of the Egyptians employed, namely, that in which a vertical section is combined with a projection, so that the interior of the building and its arrangements may be laid open to the spectator. In this instance we can see what is passing in the four principal chambers of the castle. In each chamber one or two persons are occupied over what appear to be religious rites. [Illustration: FIG. 156.--Plan, section, and elevation of a fortified city; from Layard.] In another Nimroud bas-relief we find a still greater variety of processes used upon a single work (Fig. 156). The picture shows the king enthroned in the centre of a fortified city which he has just captured. Prisoners are being brought before him; his victorious troops have erected their tents in the city itself. Beside these tents three houses of unequal size represent the dwellings of the conquered. The _enceinte_ with its towers is projected on the soil in the fashion above noticed; a longitudinal section lays bare the interiors of the tents and shows us the soldiers at their various occupations. As for the houses, they are represented by their principal facades, which are drawn in elevation. [Illustration: FIG. 157.--Plan and elevation of a fortified city; from Layard.]