Nor, continues Montfaucon, are we more disposed to credit the story told by Martinus Crusius, in his _Turco-Græciæ_, book viii.—on the authority of the Arabs—that Alexander the Great fixed on the summit of the tower a mirror so skilfully made that it revealed the approach of hostile fleets at a distance of one hundred leagues, and that after the Macedonian hero’s death it was broken by a Greek, named Sodores, while the guardians of the lighthouse slept. But, unfortunately for this romantic fiction, the pharos was not built until after the time of Alexander the Great. [Illustration] [Illustration] CHAPTER III. THE “TOUR D’ORDRE” OF BOULOGNE. Boulogne is the ancient _Bononia_ or _Gesoriacum_, “a naval place,” says Ptolemæus, “of the Morini,” and distant from the British coast, according to Pliny, about fifty _millia passuum_. Pliny probably measured from Boulogne to _Rutupiæ_ (or Richborough), where the Romans had a fortified port, and which was their usual landing-place from Gallia. His measurement, however, exaggerates the actual distance between these places. It was from Boulogne the Emperor Claudius embarked on his expedition to Britain; and it was at Boulogne the Emperor Caligula bade his soldiers collect the shells as spoils of ocean, and decreed himself a triumph for victories he had only won in imagination. As a more durable monument of his achievements, he erected, according to Suetonius, a lofty tower; the extraordinary structure which, under the name of the _Tour d’Ordre_, for centuries extorted the admiration of men. Built as a memorial of imperial vain-gloriousness, when was it first converted into a work of public utility? When did the triumphal tower become a lighthouse? To these questions we can offer no authoritative reply. But it seems probable that in A.D. 191 a light was blazing from its summit; for a bronze medal of Commodus—on which he is entitled Britannicus, in memory of his lieutenant’s victories over the Britons—represents the pharos and its fire, and the departure of a Roman fleet. Planted at the usual point of embarkation for Britain, the tower of Boulogne was carefully preserved so long as the Roman sway endured. In 811 it was repaired, according to Eginhard, by the great Western emperor, Charles, who was then preparing an expedition against the Norman pirates. As late as the seventeenth century it seems to have been employed as a lighthouse; and thence, according to a popular but certainly erroneous etymology, its ancient name of _Turris ardens_ became, by corruption, _Tour d’Ordre_. It also served as a fortress, for which it was well adapted by its admirable position and extraordinary massiveness.