aided mariners of both countries was the
caravel, a small ship with three short masts.
A caravel’s lateen (triangular) sails enabled it
to navigate against the wind, which helped
Portuguese mariners to explore the African
coast with the certainty that contrary winds
would not prevent them from returning
home. Caravels were cheaper to build and
more maneuverable than the nao, a larger
ship whose less adaptable square-rigged
sails made it useful mostly for sailing with
the wind. Columbus’s flagship, the Santa
Maria,was a nao; the Niñaand the Pinta
were caravels.
Portugal’s capital, Lisbon, was also home
to some of the best mapmakers in Europe.
Columbus and his brother Bartolomé worked
in a Lisbon cartographer’s office when they
were young men. Mariners navigated along
coastlines using charts called portolans
(from the Italian portolani,meaning “sailing
directions”), which were drawn to scale and
showed the location of ports, harbors, river
mouths, and other landmarks visible from
the sea. These charts improved as the accu-
mulating observations of mariners were
included. Portolans, however, did not depict
latitude and longitude.
In 1884 an international convention fixed
the location of the meridian—a north-south
line depicting a standard baseline of zero
longitude—at Greenwich, England. Before
then, cartographers were free to draw the
meridian wherever they liked. First-century
A.D. Greek astronomer/geographer Ptolemy
estimated it to be near the Canary Islands. In
1492 its location depended on the national-
ity of the mapmaker. Most Portuguese car-
tographers drew its line through Prince
Henry the Navigator’s headquarters at Sagres
in southwestern Portugal. Even though its
location would not be precisely standardized
on all maps for nearly another 400 years,
comparing the meridian and other lines to
The World in 1492 B 17