Archaeologists interested in the Parthenon have often noted that the west fagade was built at a higher level than that of the east fagade. Penrose especially discusses the difference in levels.' He states that the reason for the difference was an economic one, because the foundations of the Older Parthenon, upon which the Parthenon of Pericles' time rested, were also higher at the west than at the east, and that, therefore, the old foundations, to receive the stylobate of the Parthenon, needed to be shaved down a minimum, at a considerable saving in labor. Penrose's economic point is well taken, but there is another advantage which he does not mention, and which, on account of its aesthetic importance, the writer would like to explain. But, before doing so, he wishes to make a few relevant remarks about the Older Parthenon. The foundations of the Older Parthenon rest upon the rock of the Acropolis so that there was no economic need as in the case of the Parthenon to raise the west fagade of the temple. The west fagade was elevated intentionally, the reason being for an advantage which was common to both temples. If we sight along the upper courses of the south foundations of the Older Parthenon, we will see that the top two courses are cut to a beautiful upward curve,2 which also appears, of course, in the bottom step of that temple. As the Parthenon has both the raising of the west fagade and the upward curve of the stylobate, Ictinus, when he incorporated these two features in the Parthenon, was but doing what had been intended for the Older Parthenon. The difference in level of the east and west fa?ades of the Parthenon was, as suggested above, intentional. Let us demonstrate this. It is hard to