The Pyramid of Cheops, the largest of the Gizeh group, near Cairo, rises from a base covering thirteen acres, to a height of four hundred and fifty feet. According to Herodotus, Cheops employed one hundred thousand men for twenty years in its erection. PALACES AND TEMPLES.---The earlier Memphian kings built great unadorned pyramids, but the later Theban monarchs constructed splendid palaces and temples. Two of the most prominent masses of buildings on the site of Thebes are called, the one the Temple of Karnak, and the other the Temple of Luxor, from the names of two native villages built near or within the ruined enclosures. The former was more than five hundred years in building. As an adjunct of the temple at Karnak was a Hall of Columns, which consisted of a phalanx of one hundred and sixty-four gigantic pillars. Some of these columns measure over seventy feet in height, with capitals sixty-five feet in circumference. [Illustration: STATUES OF MEMNON AT THEBES.] In Nubia, beyond the First Cataract, is the renowned rock-hewn temple of Ipsambul, the front of which is adorned with four gigantic portrait- statues of Rameses II., seventy feet in height. This temple has been pronounced the greatest and grandest achievement of Egyptian art. SCULPTURE: SPHINXES AND COLOSSI.--A strange immobility, due to the influence of religion, attached itself, at an early period, to Egyptian art. The artist, in the portrayal of the figures of the gods, was not allowed to change a single line in the conventional form. Hence the impossibility of improvement in sacred sculpture. Wilkinson says that Menes would have recognized the statue of Osiris in the Temple of Amasis. Plato complained that the pictures and statues in the temples in his day were no better than those made "ten thousand years" before. The heroic, or colossal size of many of the Egyptian statues excites our admiration. The two colossi at Thebes, known as the "Statues of Memnon," are forty-seven feet high, and are hewn each from a single block of granite. The appearance of these time-worn, gigantic figures, upon the solitary plain, is singularly impressive. "There they sit together, yet apart, in the midst of the plain, serene and vigilant, still keeping their untired watch over the lapse of ages and the eclipse of Egypt." One of these statues acquired a wide reputation among the Greeks and Romans, under the name of the "Vocal Memnon." When the rays of the rising sun fell upon the colossus, it emitted low musical tones, which the Egyptians believed to be the greeting of the statue to the mother-sun. [Footnote: It is probable that the musical notes were produced by the action of the sun upon the surface of the rock while wet with dew. The phenomenon was observed only while the upper part of the colossus, which was broken off by an earthquake, remained upon the ground. When the statue was restored, the music ceased.]