Page:History of Art in Persia.djvu/182

 Vaulted Structures. FerOz-Abad none but small units of limestone occur, that are used in the rough as core to the walls, but roughly hewn into thin flat slabs when introduced in the vaults and cupolas (Fig. 83). The same system prevailed at Sarvbtan. The walls were of broken stone, whose external face was rudely prepared with the pick; courses and joints, however, were apparent, proving that the walls were not plastered. On the other hand, the cupolas were built of large square bricks, rudely dressed, but well baked. The excellentquality of the mortar — lime mixed with sand — with which the materiak were bound accounts for the marvellous state of pre- servation of these piles. Since we do not consider them as dating from the period within which we wish to confine ourselves for the present, we shall not dwell upon the processes with which the builder contrived to suspend a cupola with circular base over a square chamber. Those interested in the subject will find ample information in Dieulafoy's volume. All it is needful to remember and bring into relief is that in both instances the manner the vaults were set up betrays strange negligence or, if preferred, inexperience, which at Feruz-Abad verges on barbarism. In order to conceal the uncouth appearance of the arches, due to the nature of the materials employed, recourse was had to thick layers of plaster (Fig. 83). Their shape — though, as a rule, that of a semicircle — was by no means constant, and we find more than one instance of the extra-dosed, or " Mauresque" arch (Fig. 84). They were scarcely more skilful in the way they managed the point of junction between the top of the straight wall and the curvilinear shape of the cupola ; for no reliance is to be placed on drawings, certainly pretty to look at, but on so reduced a scale » that a very imperfect idea is gained of the detail of the execution, whilst they are utterly worthless as reference. As a matter of fact, the stonework is neither on the corbel nor on the voussoir Digitizeu lj, ^oogle