Note 328 — Chapter III · THE CONTRIBUTION OF THE MOSLEMS

Al-Khwārizmī’s Kitāb ṣūrat al-arḍ and its origins are of interest to us in view of the fact that certain of the figures there given for latitude and longitude found their way into the Toledo Tables, which were translated into Latin and enjoyed wide use in the West during the twelfth century and later (see above, pp. 243–244). Various figures given in the Kitāb ṣūrat al-arḍ were quoted by later Mohammedan writers, among them the fourteenth-century geographer Abū-l-Fidā. These formed the basis of 393the discussion of Al-Khwārizmī’s work in Lelewel’s Géographie du moyen âge, vol. i, 1852, pp. 21–29; epilogue, 1857, pp. 47–60. A manuscript of the Ṣūrat al-arḍ, the only one in existence, was discovered by Wilhelm Spitta in Cairo in 1878 and described by him in an article entitled Die Geographie des Ptolemäus bei den Arabern, 1882. Spitta’s article was completely superseded by Nallino’s more critical study (Al-Ḫuwârizmî e il suo rifacimento, 1894). Nallino shows that Lelewel’s theory, that the Kitāb ṣūrat al-arḍ is a translation of a work called Oresmos by a seventh-century Greek geographer, will not hold water. He suggested that the work was not a direct translation from Ptolemy but was composed to elucidate and explain a map which itself was compiled directly from a Greek, not Greco-Syrian, version of the Geography. The fact that Al-Khwārizmī’s figures in many cases diverge slightly from those of Ptolemy may be explained by the supposition that they were reconstructed from data given on a map, rather than copied from the text of Ptolemy’s Geography. Later and more thorough investigations into the Kitāb ṣūrat al-arḍ by Hans von Mžik confirm Nallino’s opinion that the treatise was based upon a map but show that the map itself must have been compiled from a Syrian text. Al-Khwārizmī’s work embodies the results of Moslem geographical calculations which had tended to correct Ptolemy’s overestimate of the length of the Mediterranean Sea (von Mzik, Ptolemaeus, 1915, pp. 152–176; idem, Afrika, 1916).