The Ptolemaic Geography of Africa

Abstract

AT the meeting on Monday of the Royal Geographical Society, Dr. H. Schlichter read a paper on “Ptolemy's Geography of Eastern Equatorial Africa.” Ptolemy, as a geographer, has received very different treatment at different times at the hands of his critics. At one time it was the fashion to sneer at the industrious Alexandrian geographer as entirely untrustworthy, as a mere imaginative arm-chair geographer, without critical discrimination. That Ptolemy was an arm-chair geographer no one denies, but in geography, at least, it should be remembered that the looker-on often sees most of the game. Basing his system on that of his predecessor, Marinas of Tyre, Ptolemy seems diligently to have collected the itineraries of all travellers that came within his reach, and his position at the great port of Alexandria was highly favourable for work of that kind. Of course his methods were faulty, his fundamental data erroneous, and the observations with which he had to deal often of the vaguest kind. Still, when all due allowance is made for these drawbacks, there is no denying that Ptolemy's map of North-Eastern Africa bears a wonderful resemblance to reality—just the resemblance that might be expected in the infancy of cartography, before the invention of instruments of precision, and ere travellers had learned to make good use of their eyes. Recent discoveries in Central Africa have attracted increased attention to the geography of Ptolemy, and make one wonder how he came so near the truth. It has been recently attempted by Dr. Meyer (who in this case is merely the mouthpiece of Mr. E. G. Ravenstein) to show that Ptolemy's knowledge of East Africa did not extend beyond Abyssinia; that his Nile is simply the Abyssinian River, and his lakes the lakes of that country, projected downwards, to suit later knowledge, into the heart of Africa. However that may be, Dr. Schlichter, in his paper, gives the result of an ingenious method adopted by him to test Ptolemy's accuracy, and to prove that he must have somehow obtained information about the lakes which we now know give origin to the Nile, and about the snow-clad mountains that cluster round them, and which are all that remain to us of the once famous Mountains of the Moon that extended like a barrier across the continent. After discussing Ptolemy's cartographical methods, and making allowances for his error as to the length of the degree (600 instead of 500 stadia), Dr. Schlichter's modus operandi is as follows:—