Note 114 — Chapter III · 1474-1492.

Claudius Ptolemæus, an Egyptian astronomer and geographer, lived, in the second century at Alexandria. His System of Geography, (Γεωγραφική Ἀφήγησις,) contained in eight books, was a standard work for fourteen centuries. During the first part of the sixteenth century twenty-one editions of the geography, with editions and emendations, were published. According to Ptolemy, all the known part of the earth, from the first meridian, or the Canary Islands, eastwardly, on the parallel of Rhodes, measured seventy-two thousand stadia, or one hundred and eighty degrees, which he deemed to be the half of the circumference of the globe. But the extent he was acquainted with was really measured by one hundred and twenty degrees, which made the circumference one third less than it is.

Marinus of Tyre, a Greek geographer, lived about 150 A.D. This cosmographer supposed that the country of the Seres, or Sinae (China), the farthest part of India known to the ancients, was fifteen hours, by the course of the sun, or two hundred and twenty-five degrees east of the first meridian passing through the Fortunate (Canary) Islands. According to our present geographical measurements, the distance given by Marinus was not more than one hundred and thirty degrees, leaving two hundred and thirty the remaining distance from China eastwardly to the Canary Islands. Following the deductions of Marinus, there were only one hundred and thirty-five degrees of distance between China, going eastwardly, and the Fortunate Islands.