484 Primitive Greece : Mycenian Art. at Messenia, the Parthenon, and the temple dedicated to Rome and Augustus at Ancyra and elsewhere. With regular masonry, vertical posts became useless. A door could be opened where required by leaving a void between the horizontal beds ; for technical reasons, however, the stone beam was kept much larger than the adjoining blocks, and it became a separate piece endowed with exceptional dimension and strength. This inde- pendent member, however, was joined to the horizontal courses by means of a moulding, delicately worked into a band on the blocks which play the part of uprights and continued on the stone beam. The band is simple around the doorway of the chamber at Orchomenos (Fig. 161), as well as around those of the minor domed-tombs and the rock-cut graves at Mycenae (Figs. 119, 123). But double fascial enframe the principal entrance to the twin great cupola-sepulchres at Mycenae (Figs. 118, 121, and Pis. IV.-VI.). The conclusion to be deduced from the change of style shown in the several entrances leading to the domed-tombs and the castles at Tiryns and Mycenae is as follows. The date of these citadels was not far removed from the time when irregularity of masonry compelled the builder to copy in stone the primitive wood frame of the hut. He was so far wedded to the old arrangement as to continue it in the succeeding stage, although regular courses had become pretty frequent ; but when bee-hive graves were multiplied in the lower city, the mason was so habituated to this style of construction that it seemed natural to him to contrive his openings by means of a space left in the horizontal beds that composed the wall. By itself, the difference of plan which the constructor adopted for his doorways would suffice to prove the later date of the domed-tombs, as against the citadel ramparts of Tiryns and Mycenae. Moreover, we already find in Cyclopaean masonry openings obtained without the insertion of a wooden or stone frame, by the simple system of corbelled courses (Fig. 193). But the arrangement has only been employed for subordinate openings, windows, and posterns. From a certain height the side blocks advance, each beyond its fellow underneath, and as the pro- jection of each stone forms a slight curve, the result is an entry which gives the impression of a pointed arch, rather than that of a triangle. The monuments show stones of almost every
