The fourth builder of Constantinople was Alexander the Great, who is also said to have cut the strait of Sebtah (Ceuta), which unites the White Sea (Mediterranean) with the ocean. Some say the Black Sea extends from Azák (Azof), to the straits of Islámbúl (the canal of Constantinople), the sea of Rúm (Greece), from thence to the straits of Gelíbólí (Gallipoli, _i.e._ the Hellespont), the key of the two seas, where are the two castles built by Sultán Mohammed the Conqueror, and that all below this forms the White Sea. Having often made an excursion in a boat, when the sea was smooth and the sky clear, from the Cape of the Seven Towers (_Yedí kullah búrunú_), near Islámbúl, to the point of Kází Koï (called Kalámish), near Uskudár (Scutari), I have observed in the water a red line, of about a hand’s breadth, drawn from one of these points to the other. The sea to the north of the line is the Black Sea; but to the south of it, towards Kizil Adá, and the other (Princes’) islands, is called, on account of its azure (_níl_) hue, the White Sea; and the intermixture of the two colours forms, by the command of God, as wonders never fail, a red seam (_ráddeh_), which divides the two seas from each other. This line is always visible, except when strong southerly winds blow from the islands of Mermereh (Marmora), when it disappears, from the roughness of the sea. There is also a difference in the taste of the waters on each side of this line; that towards the Black Sea being less salt and bitter than that towards the White Sea: to the south of the castles (of the Dardanelles), it is still more bitter, but less so than in the ocean. No sea has more delicious fish than the Black Sea, and those caught in the Strait of Islámbúl are excellent. As that strait unites the waters of the Black and White Seas, it is called, by some writers, the confluence of two seas (_mereju’l bahreïn_). The fifth builder of Constantinople was a king of Ungurús (Hungary), named Púzantín (Byzantinus), son of Yánkó Ibn Mádiyán, in whose time the city was nearly destroyed by a great earthquake, nothing having escaped except a castle built by Solomon, and a temple on the site of Ayá Sófiyyah. From Púzantín, Islámbúl was formerly called Púzenteh (Byzantium). The sixth builder was one of the Roman emperors; the same as built the cities of Kóniyah, Níkdeh and Kaïsariyyah (Cæsarea). He rebuilt Islámbúl, which, for seventy years, had been a heap of ruins, a nest of serpents, lizards, and owls, 2288 years before its conquest by Sultán Mohammed.