[47] Just as the first mosque in Cairo, that of ’Amr, was built entirely on columns taken from earlier buildings, Muḳaddasî describes one of the Raḳḳah mosques as [Illustration: Arabic script]; it would be satisfactory to imagine that he referred to the columned arcades of the mosque round the square minaret, but the phrase cannot reasonably be twisted into that or any other meaning. The square minaret is the ancient Syrian tower type; Thiersch has recently published an exhaustive study of it in his _Pharos_. [48] I saw traces of two such arcades on the E., N. and W. sides of the court, and, judging from the vestiges that remain, the arcades must have been three deep to the south. The bricks of the vanished arcades have been dug out and carried away for building purposes. The outer walls are so much ruined that I could not determine the position of the gates with certainty. [49] Professor van Berchem has published the inscription in his _Arabische Inschriften_, a chapter appended to the work of Professor Sarre and Dr. Herzfeld entitled _Reise in Euphrat-und Tigris-Gebiet_. But the publication has appeared too late for me to do more than refer to it. [50] M. Viollet has published a short description of these ruins (_Publications de l’Académie des Inscrip. et Belles-Lettres_, 1909, Vol. XII. part 2). He believes the palace to have been erected by Hârûn er Rashîd. [51] I expect that this is Sachau’s Bergland Tulaba--see Kiepert’s map. [52] Bk. XXIII. ch. iii. 8. [53] It was visited and planned by Sarre and Herzfeld in 1907; Sarre, _Reise in Mesopotamien_, in the _Zeitschrift der Gesch. für Erdkunde zu Berlin_, 1909, No. 7, p. 429. Sarre pronounces the greater part of the ruins to date from the time of Justinian. [54] Ibn Ḥauḳal is, I think, the first to speak of it. Idrîsî says that it had busy markets and that much traffic went through it. They wrote respectively in the tenth and twelfth centuries. [55] _Zur antiken Topographie der Palmyrene_, p. 39. [56] The reference is not, however, certain: Moritz, _op. cit._ p. 35. [57] Sachau travelled up the left bank of the Khâbûr, and should therefore have crossed the course of the canal, but he makes no mention of it. [58] I should conjecture that on the Euphrates as on the Tigris the disappearance of the settled population dates from the terrible disaster of the Mongol invasion. [59] I looked carefully for any trace of a big canal opposite Ṣâliḥîyeh and saw none. [60] _Anabasis_, Bk. I. ch. 5, 9. [61] With the doubtful contribution made by Ammianus Marcellinus to the question, I have dealt in the Appendix to this chapter. [62] _Amm. Mar._, Bk. XXIV. ch. i. 6. [63] Ed. de Goeje, p. 233. [64] Ed. Reinaud, p. 286. [65] Quoted by Ritter, Vol. XI. p. 717.