Whence came the idea of lighting the coastline with flaring beacons? It is impossible to say. They have been handed down to modern civilization through the mists of time. The first authentic lighthouse was Sigeum, on the Hellespont, which undoubtedly antedates the famous Pharos of Alexandria. The latter was a massive square tower, 400 feet high, and was known as one of the Seven Wonders of the World. It was built about 331 B.C. The warning light was emitted from a huge wood fire, which was kept burning at the summit continuously during the night; the illumination is stated to have been visible for a distance of forty miles, but modern knowledge disputes this range. The precise design of this wonderful tower is unknown, but it must have been a huge structure, inasmuch as it is computed to have cost the equivalent in modern money of over £200,000, or $1,000,000. For sixteen hundred years it guided the navigators among the waters from which it reared its smoking crest, and then it disappeared. How, no one knows, although it is surmised that it was razed by an earthquake; but, although it was swept from sight, its memory has been preserved, and the French, Italian, and Spanish nations use its name in connection with the lighthouse, which in France is called _phare_; in the other two countries mentioned, _faro_. The Romans in their conquest of Gaul and Britain brought the lighthouse with them, and several remains of their efforts in this direction are to be found in England, notably the pharos at Dover. In all probability, however, the lighthouse in its most primitive form is at least as old as the earliest books of the Bible. Undoubtedly it sprang from the practice of guiding the incoming boatman to his home by means of a blazing bonfire set up in a conspicuous position near by. Such a guide is a perfectly obvious device, which even to-day is practised by certain savage tribes. When the Phœnicians traded in tin with the ancient Britons of Cornwall, their boats continually traversed the rough waters washing the western coasts of Spain, where, for the safer passage of their sailors, doubtless, they erected beacons upon prominent headlands. The oldest lighthouse in the world to-day, which in some quarters is held to be of Phœnician origin, is that at Corunna, a few miles north of Cape Finisterre. Other authorities maintain that it was built during the reign of the Roman Emperor Trajan. In 1634 it was reconstructed, and is still in existence.