But the chief wonder of the Parthenon was the colossal statue of the Virgin Goddess executed by Phidias himself, which stood in the eastern or principal chamber of the cella. It was of the sort called CHRYSELEPHANTINE, a kind of work said to have been invented by Phidias in which ivory was substituted for marble in those parts which were uncovered, while the place of the real drapery was supplied with robes and other ornaments of solid gold. Its height, including the base, was nearly 40 feet. It represented the goddess standing, clothed with a tunic reaching to the ankles, with a spear in her left hand, and an image of Victory in her right. The Acropolis was adorned with another colossal figure of Athena, in bronze, also the work of Phidias. It stood in the open air, nearly opposite the Propylaea, and was one of the first objects seen after passing through the gates of the latter. With its pedestal it must have stood about 70 feet high, and consequently towered above the roof of the Parthenon, so that the point of its spear and the crest of its helmet were visible off the promontory of Sunium to ships approaching Athens. It was called the "Athena Promachus," because it represented the goddess armed, and in the very attitude of battle. The only other monument on the summit of the Acropolis which it is necessary to describe is the Erechtheum, or temple of Erechtheus. The traditions respecting Erechtheus vary, but according to one set of them he was identical with the god Poseidon. He was worshipped in his temple under the name of Poseidon Erechtheus, and from the earliest times was associated with Athena as one of the two protecting deities of Athens. The original Erechtheum was burnt by the Persians, but the new temple was erected on the ancient site. This could not have been otherwise; for on this spot was the sacred olive-tree which Athena evoked from the earth in her contest with Poseidon, and also the well of salt-water which Poseidon produced by a stroke of his trident, the impression of which was seen upon the rock. The building was also called the temple of Athena Polias, because it contained a separate sanctuary of the goddess, as well as her most ancient statue. The building of the new Erechtheum was not commenced till the Parthenon and Propylaea were finished, and probably not before the year preceding the breaking out of the Peloponnesian war. Its progress was no doubt delayed by that event, and it was probably not completed before 393 B.C. When finished it presented one of the finest models of the Ionic order, as the Parthenon was of the Doric, It stood to the north of the latter building and close to the northern wall of the Acropolis. The form of the Erechtheum differed from every known example of a Grecian temple. Usually a Grecian temple was an oblong figure with a portico at each extremity. The Erechtheum, on the contrary, though oblong in shape and having a portico at the eastern or principal front, had none