Ptolemy’s East Africa in Early Medieval Arab Geography
By M.A. Tolmacheva
Journal for the History of Arabic Science, Vol.9 (1991)
Introduction: The well recognized debt of Arab geographt to Claudius Ptolemy made a profound impression on the development of Arabic geographic science which goes far beyond mere translataions of his Geography. From as early as the ninth century and as late as the 15th century mst Arabic authors writing in the genres of descriptive and mathematical geography echoed Ptolemy as a source for systematic description of the habitable earth. The major areas in which Ptolemaic influence made an impact on Islamic scholars include geographic data: description of continents and seas, and the coordinates of settlements and of topographic features, geographic theory, and cartography.
This paper is a re-examination of the nature and extent of the Greek influence of Arab geography traditionally ascribed to Ptolemy, limited to those early medieval Arabic works which demonstrate a recognized familiarity with Ptolemy on all three levels. These include the writings of the famous early mathematician, astronomer and geographer Muhammad ibn Musa al-Khorezmi (d. c.232/846-847) and his less well known editor Suhrab (the first half of the tenth centruy AD) as well as the Kitab al-zij al-Sabi by the great astronomer al-Bittani (d.317/929). Their data will be explored below with a view toward certain special considerations regarding the histrorical geography of East Africa. In addition, some questions of general methodology of interpreting data derived from manuscript Arabic sources will be considered.