Upon the third day thou didst command
that the waters should be gathered in
the seventh part of the earth: six parts
hast thou dried up, and kept them, to the
intent that of these some being planted of
God and tilled might serve thee. (2 Esdras
6:42)Consequently, most of the globe must be
land. This misapprehension led Christopher
Columbus to optimistically calculate that the
Earth was much smaller than it is and that
the westwarddistance from Europe to Asia
was relatively short.
The landmasses that geographers mistak-
enly believed to cover six-sevenths of the
Earth were divided by rivers and “the ocean
sea,” asingle ocean. The modern concept of
continents did not exist. The three major
landmasses of the known world consisted of
Africa, Asia, and Europe, as well as a profu-
sion of islands. The westernmost of these
islands in the North Atlantic Ocean—the
Canaries, the Azores, and Madeira—were
known to European mariners. Portugal was
still colonizing the Canary Islands in 1492,
developing them into the important supply
post they would become for transatlanticThe World in 1492 B 19
far east or west their ships
had traveled by multiplying
their rate of speed by the pas-
sage of time. A floating log
attached to a knotted rope
would be thrown from the
stern or rear of the ship. The
navigator would time the
unspooling of the rope with a
sandglass and count the
number of knots in the rope
(this was the origin of using
the word knots to describe
thespeed of ships). After fac-
toring in changes of direction
with the help of a compass,
an estimate could be made of
howfar the ship had traveled
in a day.
Navigating with these sys-
tems was never completely
accurate. They were, however,
the best methods technology
had to offer navigators such
as Columbus in 1492.This astrolabe, an instrument used to determine
latitude, dates to the early 17th century.
(National Archives of Canada)