This system is probably the one the Turks found in use when they entered the city. Water still runs in the aqueducts of Valens and Justinian, and until the present generation Stamboul had no other water-supply than that first collected by Hadrian and Constantine. The Sultans restored and improved it, but I have no doubt that the conduits of many a Turkish fountain were laid by a Roman emperor. Of Byzantine fountains remaining to this day, I am not sure that any can positively be identified as such. Many of the fountains of Stamboul, however, must occupy the place of Byzantine fountains, whose materials may have been used in their construction. And it would not have been strange if the new masters of the city adapted to their own use models which they saw about them. The great quadruple fountain of Kîrk Cheshmeh—Forty Fountains—is a case in point. The Turks connect with it the name of Sultan Süleïman I, who is said to have left forty fountains in the city. But its original level was considerably below the existing street, and one of the four niches is ornamented with a Byzantine relief of peacocks, while other Byzantine fragments are built into the structure. The arches of two of the niches, moreover, are round, which was not characteristic of Süleïman’s period. So we are not without reasons for thinking that the fountain may have been a Byzantine one restored by Süleïman—who also restored the aqueduct that feeds it. The same is likely of others of his forty fountains. No others of them bear Byzantine sculptures. In fact, the only other street fountain on which I have seen any such decoration—unless the goose of Kazlî be Byzantine—is that of the small Koumrülü Mesjid, between Fatih and the Adrianople Gate. But the large Horhor Cheshmeh near Ak Seraï, and another farther up the hill toward the old Forum Amastrianon, have a distinct Byzantine air. At the same time, their general form is that of the Turkish wall fountain—an arched niche, containing a faucet above a stone or marble trough. This form, in its simplest state, without any ornament or even a “mirror stone,” is found in what may be the oldest Turkish fountain in Constantinople. It lies within the enclosure of the castle of Roumeli Hissar. The niche is deeper than in later fountains, and the bricks used in its construction are the large flat ones which the Turks borrowed from their predecessors. If truth compels me further to record that the arch is not the pointed one preferred by the Turks until the eighteenth century, I am able to add that neither are the arches of the castle itself. [Illustration: The Byzantine fountain of Kîrk Cheshmeh]