| Maps and Charts of the
Fifteenth Century |
Mariners during the 15th century relied on charts called "portolans" to assist them on
their voyages. Portolan comes from the Italian
word portolani, which were medieval pilot books.
The portolans contained maps of coastlines, locations
of harbors, river mouths, and manmade features
visible from the sea. They were a compilation
of centuries of seafarer observations. As sailors'
skills improved and the use of the compass was more widespread, portolans improved in accuracy.
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Portuguese chartmakers
added the meridian line, a point useful for latitude sailing
as well as for navigating solely by compass.
A geographic feature could now be located
through the use of its distance in degree
of latitude from a ship's point of departure.
The use of latitude and longitude was understood since the time of Ptolemy in the second century A.D. He assigned coordinates
to place names. The use of latitude and
longitude posed difficulties while sailing
on the high seas. |
Portuguese
explorers | Portuguese
Ships | Navigation
Methods | 15th-century
maps & charts |