Note 11 — INTRODUCTION.

In Columbus' letters to Queen Isabella in 1498, we catch, as it were, the last echo of the Arabic mélange of Moses and Greek geography, along with the results of Roger Bacon's corrections of Ptolemy. "The Old Hemisphere," he writes "which has for its centre the isle of Arim, is spherical, but the other (new) Hemisphere has the form of the lower half of a pear. Just one hundred leagues west of the Azores the earth rises at the Equator and the temperature grows keener. The summit is over against the mouth of the Orinoco."