Of some of the interior parts of Africa Ptolemy possessed clear and
accurate information; regarding others, he presents us with a mass of
confused notions. He clearly points out the Niger, though he fixes its
source in a wrong latitude. In the cities of Tucabath and Tagana, which he
places on its banks, may perhaps be recognized Tombuctoo and Gana. The most
striking defect in his geography of the interior of Africa is, that he does
not allow sufficient extent to the great desert of Sahara, while the
southern parts are too much expanded. He places the sources of the Nile,
and the Mountains of the Moon in south latitude thirteen, instead of north
latitude six or seven; but the error of latitude is not so remarkable and
unaccountable as the very erroneous latitude which he assigns to Cape
Aromata, on a coast which was visited every year by merchants he must have
seen at Alexandria. The most difficult point to explain in Ptolemy's
central Africa is the river Gir, which he describes as equal in length to
the Niger, and running in the same direction, till it loses itself in the
same lake. What this river is, geographers have not agreed. It is mentioned
by Claudian, as resembling the Nile in the abundance of its waters.
Agethimedorus, a geographer of the third century, regards it and the Niger
as the same river.
What then was the amount of the knowledge of the ancients, as it existed
among the Romans, in the height of their power, respecting the form,
extent, and surface of the globe? If we view a map drawn up according to
their ideas, we are immediately struck with the form they assigned the
world, and perceive with what propriety they called the extent of the world
from east to west longitude or _length_, and the extent from north to
south latitude, or _breadth_.
Pages:
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457