quatorial circumference at almost exactly the
true figure; his error was less than 124 English miles in excess. The
circumference in the latitude of Lisbon he made 26 x 250 x 3 = 19,500
miles.[461] Two thirds of this figure, or 13,000 miles, he allowed for
the length of the Oecumene, from Lisbon eastward to Quinsay (i. e.
Hang-chow), leaving 6,500 for the westward voyage from Lisbon to
Quinsay. Thus Toscanelli elongated Asia by nearly the whole width of the
Pacific ocean. His Quinsay would come about 130 deg. W., a few hundred miles
west of the mouth of the Columbia river. Zaiton (i. e. Chang-chow), the
easternmost city in Toscanelli's China, would come not far from the tip
end of Lower California. Thus the eastern coast of Cipango, about a
thousand miles east from Zaiton, would fall in the Gulf of Mexico
somewhere near the ninety-third meridian, and that island, being over a
thousand miles in length north and south, would fill up the space
between the parallel of New Orleans and that of the city of Guatemala.
The westward voyage from the Canaries to Cipango, according to
Toscanelli, would be rather more than 3,250 miles, but at a third of the
distance out he placed the imaginary island of "Antilia," with which he
seems to have supposed Portuguese sailors to be familiar.[462] "So
through the unknown parts of the route," said the venerable astronomer,
"the stretches of sea to be traversed are not great,"--not much more
than 2,000 English miles, not so long as the voyage from Lisbon to the
Guinea coast.

[Sidenote: Columbus's opinion of the size of the globe, the length of
the Oecumene, and the width of the Atlantic ocean.]

[Sidenote: The fourth book of Esdras.]

While Columbus attached great importance to these calculations and
carried Toscanelli's map with him upon his first voyage, he improved
somewhat upon the estimates of distance, and thus made his case still
more hopeful. Columbus was not enough of an astronomer to adopt
Toscanelli's improved measurement of the size of the earth. He accepted
Ptolemy's figure of 20,400 geographical miles for the equatorial
girth,[463] which would make the circumference in the latitude of the
Canaries about 18,000; and Columbus, on the strength of sundry passages
from ancient authors which he found in Alliacus (cribbed from Roger
Bacon), concluded that six sevenths of this circumference must be
occupied by the Oecumene, including Cipango, so that in order to reach
that wonderful