caravel A small, maneuverable, three-mast sailing ship developed by the Portuguese in the fifteenth century that gave the Portuguese a distinct advantage in exploration and trade.
Ptolemy’s Geography Second century C.E. work that synthesized the classical knowledge of geography and introduced the concepts of longitude and latitude. Reintroduced to Europeans in 1410 by Arab scholars, its ideas allowed cartographers to create more accurate maps.
Technological developments in shipbuilding, navigation, and weaponry provided another impetus for European expansion. In the course of the fifteenth century, the Portuguese developed the caravel, a small, light, three-mast sailing ship. The caravel was maneuverable, sturdy, and could be sailed with a small crew. When fitted with cannon, it could dominate larger vessels.
Great strides in cartography and navigational aids were also made during this period. Around 1410 Arab scholars reintroduced Europeans to Ptolemy’s Geography. Written in the second century, the work synthesized the geographical knowledge of the classical world. It represented a major improvement over medieval cartography, showing the world as round and introducing the idea of latitude and longitude to plot position accurately. It also contained significant errors. Unaware of the Americas, Ptolemy showed the world as much smaller than it is, so that Asia appeared not very distant from Europe.
The magnetic compass enabled sailors to determine their direction and position at sea. The astrolabe, an instrument invented by the ancient Greeks and perfected by Muslim navigators, was used to determine the altitude of the sun and other celestial bodies. It permitted mariners to plot their latitude, that is, their precise position north or south of the equator.
Like the astrolabe, Europeans borrowed much of the technology for their voyages from the East. Gunpowder, the compass, and the sternpost rudder were Chinese inventions. The lateen sail, which allowed European ships to tack against the wind, was a product of the Indian Ocean trade world. Advances in cartography also drew on the rich tradition of Judeo-Arabic mathematical and astronomical learning in Iberia. In exploring new territories, European sailors thus called on techniques and knowledge developed over centuries in China, the Muslim world, and trading centers along the Indian Ocean.