it registered _three tons_ to the foot! The most noted lighthouse in the world was undoubtedly the Pharos of Alexandria, named from the island on which it stood. The French, Italians, and Spaniards to-day use the term almost in its original purity: thus, French for lighthouse, _phare_; Italian and Spanish, _faro_. It was commenced by the first Ptolemy, and finished about 280 B.C., the workmanship, according to all accounts, being superb. This tower of white stone was 400 feet high. It is stated by Josephus that the light, which was always kept burning on its top at night, was visible over forty miles. It is believed to have been destroyed by an earthquake, though the date of its destruction is unknown. The Romans were the first to erect anything approaching a Pharos, or lighthouse, on our coasts. Beacon fires may have been occasionally used before; the conquerors made the matter an organised affair. On either side the Channel, at Boulogne and Dover, structures of no mean altitude were raised for this purpose. That at Boulogne is supposed to have been erected by Caligula; all vestiges of it have passed away. It was originally called _Turris Ardens_, afterwards corrupted to the _Tour d’Ordre_. From a description left by Claude Châtillon, engineer to Henry IV., it appears that it was built about a stone’s throw from the edge of the cliff, above and overlooking the high tower and the castle. Its form was octagonal, with a base 192 feet in circumference. It was built of grey stone with thin red bricks between. That at Dover still exists. It occupies the highest point of the lofty rock on which the famous castle is built. This Pharos was also octagonal in outward form, being square within. It is 33 feet in diameter, and formerly about 72 feet high. On the summit three holes on the three exterior sides indicate their purposes, both for look-out and for exhibiting a light seawards. Long after, and indeed almost down to our days, fire-beacons were far more common on exposed parts of our coasts than lighthouses. “The first idea of a lighthouse,” said Faraday, “is the candle in the cottage window, guiding the husband across the water or the pathless moor.” Lambarde says of the lights shown along the coast that, “Before the time of Edward III., they were made of great stacks of wood; but about the eleventh yeere of his raigne it was ordained that in our shyre (Kent) they should be high standards with their pitchpots.” Such were long used. Lighthouses in these days differ greatly in material and mode of construction. Stone, brick, cast and wrought iron, and even wood, are used, according to the necessities of the case, or the lacks of the special locality where they are placed. In the case of some iron lighthouses they are literally screwed into the rock or hard ground. Seventy of this class of structures now exist in the United States. [Illustration: THE TOWER OF CORDOUAN.]