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Page 21 of 110
CHAPTER III. ALEXANDRIA. - Cleopatra
Seeing the subject in this light, the Egyptian sovereigns, especially Alexander and the earlier Ptolemies, made every effort in their power to promote the commercial greatness of Alexandria. They built palaces, it is true, but they also built warehouses.
One of the most expensive and celebrated of all the edifices that they reared was the light-house which has been already alluded to. This light-house was a lofty tower, built of white marble. It was situated upon the island of Pharos, opposite to the city, and at some distance from it. There was a sort of isthmus of shoals and sand-bars connecting the island with the shore. Over these shallows a pier or causeway was built, which finally became a broad and inhabited neck. The principal part of the ancient city, however, was on the main land.
The curvature of the earth requires that a light-house on a coast should have a considerable elevation, otherwise its summit would not appear above the horizon, unless the mariner were very near. To attain this elevation, the architects usually take advantage of some hill or cliff, or rocky eminence near the shore. There was, however, no opportunity to do this at Pharos; for the island was, like the main land, level and low. The requisite elevation could only be attained, therefore, by the masonry of an edifice, and the blocks of marble necessary for the work had to be brought from a great distance. The Alexandrian light-house was reared in the time of Ptolemy Philadelphus, the second monarch in the line. No pains or expense were spared in its construction. The edifice, when completed, was considered one of the seven wonders of the world. It was indebted for its fame, however, in some degree, undoubtedly to the conspicuousness of its situation, rising, as it did, at the entrance of the greatest commercial emporium of its time, and standing there, like a pillar of cloud by day and of fire by night, to attract the welcome gaze of every wandering mariner whose ship came within its horizon, and to awaken his gratitude by tendering him its guidance and dispelling his fears.
The light at the top of the tower was produced by a fire, made of such combustibles as would emit the brightest flame. This fire burned slowly through the day, and then was kindled up anew when the sun went down, and was continually replenished through the night with fresh supplies of fuel. In modern times, a much more convenient and economical mode is adopted to produce the requisite illumination. A great blazing lamp burns brilliantly in the center of the lantern of the tower, and all that part of the radiation from the flame which would naturally have beamed upward, or downward, or laterally, or back toward the land, is so turned by a curious system of reflectors and polyzonal lenses, most ingeniously contrived and very exactly adjusted, as to be thrown forward in one broad and thin, but brilliant sheet of light, which shoots out where its radiance is needed, over the surface of the sea. Before these inventions were perfected, far the largest portion of the light emitted by the illumination of light-house towers streamed away wastefully in landward directions, or was lost among the stars. ![]()
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