Constantine, the first Christian among the emperors of Rome, conveyed to Byzantium, as a decoration for his new city of Constantinople, an obelisk of the period of Thothmes III., which now graces the Atmeidan, or Hippodrome: it stood originally at Heliopolis, and was one of the Needles of Pharaoh. He likewise, in all probability, sent to Arles the obelisk which is now standing in that city. It was found, in later times, grown over with bushes, and partly buried in a garden at the port of La Roquette. Charles the Second and Catherine de Medicis ordered its disinterment, and it was erected at Arles, as a memorial of Louis the Great, in the year 1676. Constantine directed the removal of another obelisk from Heliopolis, and this he also intended for Constantinople; but dying previously to its arrival at Alexandria, it was conveyed to Rome by his son Constantius. This latter is the beautiful obelisk set up in the Piazza of St. John Lateran at Rome: it is the tallest obelisk known; and although it has lost three feet of its base, measures at present 105 feet 7 inches. It bears the signets of Thothmes III. and Thothmes IV., and is the obelisk previously mentioned as having occupied thirty-six years in the preparation. The temple of Serapis at Alexandria formerly possessed two fine obelisks, but both have now disappeared; they, probably, may also have found their way to Rome. The ruins of this temple were called the citadel; and all that remains of both is Pompey’s Pillar, which was erected in one of the principal courts of the temple. [Illustration: Pompey’s Pillar at Alexandria.] Pompey’s Pillar is a magnificent column, placed on a hillock just outside the walls of the old town. It is cut out of red syenic granite; is beautifully polished, and is said to be the largest monolithic pillar in the world; its total height, according to Captain Smyth, being 99 feet 4¾ inches; or, in round numbers, 100 feet, including the pedestal; its girth, near the base, being nearly 28 feet. It is surmounted with a Corinthian capital, of a differently coloured granite from that of the shaft, and of inferior workmanship, and stands on a short stump of a broken obelisk about four feet high, inverted, and built into the pedestal; the surface of the obelisk being covered with hieroglyphs. The column was ascended by the French in 1798, and by Captain Smyth in the spring of 1822. Captain Smyth wished to ascertain its qualification for astronomical purposes; but found it too unsteady for delicate observations; and, moreover, that it had an inclination to the south-west, in the direction opposite to that of the prevailing north-east wind. It has an inscription on the pedestal, which cost much time and perseverance to make out,[13] and was at length deciphered as follows:— “Consecrated to the adorable Emperor Augustus Diocletian, the tutelar divinity of Alexandria, by Pontius, prefect of Egypt.”