THESEUM, ERECHTHEUM, AND OTHER WORKS. 159 to the south was the prostasis of the maidens (the Caryatid Porch). (Fig. 160.) The north portico and west wall were at a lower level than the east end and south side ; this difference of level was occasioned by its being built on the brow of the Acropolis. (See the model at the Museum.) The irregu- larity of the plan seems to have been conditioned by various sacred sites which were to be sheltered by the building. Dorpfeld considered that this irregularity was the result of Fig. 159. — The Erechtheum : Plan showing different levels. a change of scheme, and that the body was originally in- tended to be continued westward until the north porch became central. Petersen, in the most recent study of the subject, does not accept this view, and acutely observes that any irregular plan may be made symmetrical by doubling it over from some imaginary central line. I can see no reason for supposing that the building was not planned as it has come down to us, together with the west wall and its columns. As to the last, Prof
