Cosmography and Geography in Early Indian Literature c8.s2.t1.4

c8.s2.t1.4

6. Claudias Ptolemaeus, the Greek mathematician, astronomer and geographer, flourished in Alexandria in Egypt during the reign of Antoninus Pius in the second century A.D. In his Geography which is divided into 8 Parts, he assumes the sphere of earth to be 180,000 stadia in circumference, a degree of the equator being 500 stadia instead of 600 which is its real length. He estimated the length of the inhabited part of the earth, as measured along the parallel of Rhodes which divided the then known world into two almost equal parts, at 72,000 stadia and its breadth at 40,000 stadia. He calculated his longitudes from the meridian in the West which was that passing through the Islands of the Blest (probably the Canary Islands), his most eastern meridian being that passing through the metropolis of Sinai, called Sinai or Thinai and placed in 180° 40' E. long. and 3° S. lat. The distance of this meridian from that of Alexandria was estimated at 119½ degrees and the distance of the first meridian from the same at 60½ degrees thus making 180 degrees together or one-half of the earth's circumference. Ptolemy estimated the breadth of the earth to be 40,000 stadia. His system not only suffers from the basic mistakes of calculation referred to above, but also from imperfect knowledge of the location of places in many parts of the world.