Though the most ancient, the honour was not reserved to it of bequeathing its name to its successors. This honour was bestowed on the celebrated tower erected on the island of Pharos, off the harbour of Alexandria, which served as a model for some of the noblest lighthouses built in later ages. Thus, it was the type followed by the Emperor Claudius in the pharos raised at Ostia, near the mouth of the Tiber, which appears to have been the completest of any on the Italian coast. This pharos was situated upon a breakwater, or artificial island, which occupied the mid channel between the two massive piers that formed the harbour, and its ruins were extant as late as the fifteenth century, when they were visited by Pope Pius II. Scarcely inferior in architectural excellence was the pharos which conducted the homeward-bound into the prosperous harbour of Puteoli; or that which Augustus erected at Ravenna; or that which from the mole of Messina poured its useful splendour over the seething waters of Charybdis; or that which embellished the island of Capreæ, the favourite retreat of Tiberius, and was destroyed by an earthquake shortly before the emperor's death. [Sidenote: Ancient lighthouses.] We read of a famous lighthouse at the mouth of the river Chrysorrhoas, which flows into the Thracian Bosporus (that is, the Strait of Constantinople). On the crest of the hill washed by this river may be seen, says an old writer, the Timean Tower, a tower of extraordinary height, from whose summit the spectator may survey a wide expanse of sea. It has been built for the safety of the navigator, and fires are kindled upon it for his guidance; a precaution all the more necessary because the shores of this strait are without ports, and no anchor can reach the bottom. But the barbarians in the neighbourhood light other fires upon elevated points of the coast, in order to deceive the mariner, and profit by his shipwreck. [Sidenote: The Alexandrian pharos.] The pharos, or lighthouse, at Alexandria, to which we have referred, was built by an architect named Sostrates, in the reign, it is said, of Ptolemæus Philadelphus. The island on which it stood lay in front of the wealthy city of Alexandria, so as to protect both its harbours, the Greater Harbour and the Haven of Happy Return, from the northern gales, and the inrush of the Mediterranean. It forms a ledge of dazzlingly white calcareous rock, the northern slope of which is fringed with islets, which, in the fourth and fifth centuries of our era, were inhabited by Christian hermits. A deep inlet on that side was called the Pirates' Creek, because, in very early times, it had been the resort of the Carian and Samian sea-rovers.