Portuguese nautical science

Portuguese nautical science evolved from the successive expeditions and experience of the Portuguese pilots. It led to a fairly rapid evolution, creating an elite of astronomers, navigators, mathematicians and cartographers. Among them stood Pedro Nunes with studies on how to determine latitude by the stars, and João de Castro, who made important observations of magnetic declination over the entire route around Africa.

Ships

Until the 15th century, the Portuguese were limited to cabotage navigation using barques and barinels (ancient cargo vessels used in the Mediterranean). These boats were small and fragile, with only one mast with a fixed quadrangular sail and did not have the capabilities to overcome the navigational difficulties associated with southward oceanic exploration, as the strong winds, shoals and strong ocean currents easily overwhelmed their abilities. They are associated with the earliest discoveries, such as the Madeira Islands, the Azores, the Canaries, and to the early exploration of the northwest African coast as far south as Arguim in the current Mauritania.

The ship that truly launched the first phase of the Portuguese discoveries along the African coast was the caravel, a development based on existing fishing boats. They were agile and easier to navigate, with a tonnage of 50 to 160 tons and 1 to 3 masts, with lateen triangular sails allowing luffing. The caravel's limited capacity for cargo and crew were its main drawbacks, but these did not hinder its success. Among the famous caravels are Berrio, which was the first ship of Vasco da Gama's first armada to reach Portugal after the voyage, and Anunciação (Nossa Senhora da Anunciação), which sailed with Cabral in 1500.

With the start of long oceanic sailing, larger ships were also developed. "Nau" was the Portuguese archaic synonym for any large ship, primarily merchant ships. Due to the piracy that plagued the coasts, they began to be used in the navy and were provided with cannon ports, which led to the classification of "naus" according to the power of the ship's artillery. They were also adapted to the increasing maritime trade: from 200 tons capacity in the 15th century to 500 tons later, they become impressive in the 16th century, having usually two decks, fighting castles fore and aft, and two to four masts with overlapping sails. In voyages to India in the sixteenth century, carracks were also used. These were large merchant ships with a high edge (freeboard) and three masts with square sails, which often reached 2000 tons.

Celestial navigation

In the thirteenth century celestial navigation was already known, guided by the sun position. For celestial navigation the Portuguese, like other Europeans, used Arab navigation tools, like the astrolabe and quadrant, which they made easier and simpler. They also created the cross-staff, or cane of Jacob, for measuring at sea the height of the sun and other stars. The Southern Cross become a reference upon arrival in the Southern hemisphere by João de Santarém and Pedro Escobar in 1471, starting the use of this constellation in celestial navigation. But the results varied throughout the year, which required corrections.

To this the Portuguese used the astronomical tables (Ephemeris), precious tools for oceanic navigation, which experienced a remarkable diffusion in the fifteenth century. These tables revolutionized navigation, allowing mariners to calculate their latitude. Vasco da Gama and Pedro Álvares Cabral used the tables of the Almanach Perpetuum by astronomer Abraham Zacuto, which were published in Leiria in 1496, along with his improved astrolabe.

Sailing techniques

North Atlantic
gyre

North Atlantic
gyre

North Atlantic
gyre

Indian
Ocean
gyre

North
Pacific
gyre

South
Pacific
gyre

South Atlantic
        gyre

World map of the five major ocean gyres

Besides coastal exploration, Portuguese also made trips off in the ocean to gather meteorological and oceanographic information (in these trips were discovered the archipelagos of Madeira and the Azores, and the Sargasso Sea). The knowledge of wind patterns and currents – the trade winds and the oceanic gyres in the Atlantic, and the determination of latitude led to the discovery of the best ocean route back from Africa: crossing the Central Atlantic to the latitude of the Azores, using the permanent favorable winds and currents that spin clockwise in the Northern Hemisphere because of atmospheric circulation and the Coriolis effect, facilitating the way to Lisbon and thus enabling the Portuguese to venture increasingly farther from shore, the maneuver that became known as "Volta do mar". In 1565, application of this principle in the Pacific Ocean led to the Spanish discovery of the Manila Galleon trade route between Mexico and the Philippines.

Cartography

It is thought that Jehuda Cresques, son of the Catalan cartographer Abraham Cresques has been one of the notable cartographers at the service of Prince Henry. However, the oldest signed Portuguese sea chart is a Portolan made by Pedro Reinel in 1485 representing Western Europe and parts of Africa, reflecting the explorations made by Diogo Cão. Reinel was also author of the first nautical chart known with an indication of latitudes in 1504 and the first representation of a Wind rose.

With his son, cartographer Jorge Reinel and Lopo Homem, they participated in the making of the atlas known as "Lopo Homem-Reinés Atlas" or "Miller Atlas", in 1519. They were considered the best cartographers of their time, with Emperor Charles V wanting them to work for him. In 1517 King Manuel I of Portugal handed Lopo Homem a charter giving him the privilege to certify and amend all compass needles in vessels.

In the third phase of the former Portuguese nautical cartography, characterized by the abandonment of the influence of Ptolemy's representation of the East and more accuracy in the representation of lands and continents, stands out Fernão Vaz Dourado (Goa ~ 1520 – ~ 1580), giving him a reputation as one of the best cartographers of the time. Many of his charts are large scale.

See also

• Iberian ship development, 1400–1600
• Iberian nautical sciences, 1400–1600
• Iberian cartography, 1400–1600
• List_of_Portuguese_inventions_and_discoveries#Nautical_science

References

• Albuquerque, Fernando (1983). Ciência e Experiência nos Descobrimentos Portugueses. Biblioteca Breve. Lisboa: Instituto de Cultura e Língua Portuguesa.
• CORTESÃO, Armando. History of Portuguese Cartography. Coimbra: Junta de Investigações do Ultramar, 1969-1971 (2 v.)
• CORTESÃO, Armando. Contribution of the portuguese to Scientific Navigation and Cartography. Coimbra: Junta de Investigações Científicas do Ultramar, 1974. 30p.
• CORTESÃO, Armando; MOTA, Avelino Teixeira da. Portugaliae Monumenta Cartographica. Lisboa: Imprensa Nacional-Casa da Moeda, 1987. 6 v. + 1 v. (mapas).

• v
• t
• e

Portuguese Empire

North Africa

15th century 1415–1640 Ceuta 1458–1550 Alcácer Ceguer (El Qsar es Seghir) 1471–1550 Arzila (Asilah) 1471–1662 Tangier 1485–1550 Mazagan (El Jadida) 1487–16th century Ouadane 1488–1541 Safim (Safi) 1489 Graciosa 16th century 1505–1541 Santa Cruz do Cabo de Gué (Agadir) 1506–1525 Mogador (Essaouira) 1506–1525 Aguz (Souira Guedima) 1506–1769 Mazagan (El Jadida) 1513–1541 Azamor (Azemmour) 1515–1541 São João da Mamora (Mehdya) 1577–1589 Arzila (Asilah)

Sub-Saharan Africa

15th century 1455–1633 Arguim 1462–1975 Cape Verde 1470–1975 São Tomé1 1471–1975 Príncipe1 1474–1778 Annobón 1478–1778 Fernando Poo (Bioko) 1482–1637 Elmina (São Jorge da Mina) 1482–1642 Portuguese Gold Coast 1498–1540 Mascarene Islands 16th century 1500–1630 Malindi 1501–1975 Portuguese Mozambique 1502–1659 Saint Helena 1503–1698 Zanzibar 1505–1512 Quíloa (Kilwa) 1506–1511 Socotra 1508–15472 Madagascar3 1557–1578 Accra 1575–1975 Portuguese Angola 1588–1974 Cacheu4 1593–1698 Mombassa (Mombasa) 17th century 1645–1888 Ziguinchor 1680–1961 São João Baptista de Ajudá, Benin 1687–1974 Bissau4 18th century 1728–1729 Mombassa (Mombasa) 1753–1975 Portuguese São Tomé and Príncipe 19th century 1879–1974 Portuguese Guinea 1885–1974 Portuguese Congo5 1 Part of São Tomé and Príncipe from 1753. 2 Or 1600. 3 A factory (Anosy Region) and small temporary coastal bases. 4 Part of Portuguese Guinea from 1879. 5 Part of Portuguese Angola from the 1920s.

Middle East [Persian Gulf]

16th century 1506–1615 Gamru (Bandar Abbas) 1507–1643 Sohar 1515–1622 Hormuz (Ormus) 1515–1648 Quriyat 1515–? Qalhat 1515–1650 Muscat 1515?–? Barka 1515–1633? Julfar (Ras al-Khaimah) 1521–1602 Bahrain (Muharraq • Manama) 1521–1529? Qatif 1521?–1551? Tarut Island 1550–1551 Qatif 1588–1648 Matrah 17th century 1620–? Khor Fakkan 1621?–? As Sib 1621–1622 Qeshm 1623–? Khasab 1623–? Libedia 1624–? Kalba 1624–? Madha 1624–1648 Dibba Al-Hisn 1624?–? Bandar-e Kong

South Asia

15th century 1498–1545 Laccadive Islands (Lakshadweep) 16th century Portuguese India  • 1500–1663 Cochim (Kochi)  • 1501–1663 Cannanore (Kannur)  • 1502–1658  1659–1661 Quilon (Coulão / Kollam)  • 1502–1661 Pallipuram (Cochin de Cima)  • 1507–1657 Negapatam (Nagapatnam)  • 1510–1961 Goa  • 1512–1525  1750 Calicut (Kozhikode)  • 1518–1619 Portuguese Paliacate outpost (Pulicat)  • 1521–1740 Chaul   (Portuguese India)  • 1523–1662 Mylapore  • 1528–1666 Chittagong (Porto Grande De Bengala)  • 1531–1571 Chaul  • 1531–1571 Chalé  • 1534–1601 Salsette Island  • 1534–1661 Bombay (Mumbai)  • 1535 Ponnani  • 1535–1739 Baçaím (Vasai-Virar)  • 1536–1662 Cranganore (Kodungallur)  • 1540–1612 Surat  • 1548–1658 Tuticorin (Thoothukudi)  • 1559–1961 Daman and Diu  • 1568–1659 Mangalore   (Portuguese India)  • 1579–1632 Hugli  • 1598–1610 Masulipatnam (Machilipatnam) 1518–1521 Maldives 1518–1658 Portuguese Ceylon (Sri Lanka) 1558–1573 Maldives 17th century Portuguese India  • 1687–1749 Mylapore 18th century Portuguese India  • 1779–1954 Dadra and Nagar Haveli

East Asia and Oceania

16th century 1511–1641 Portuguese Malacca [Malaysia] 1512–1621 Maluku [Indonesia]  • 1522–1575  Ternate  • 1576–1605  Ambon  • 1578–1650  Tidore 1512–1665 Makassar [Indonesia] 1515–1859 Larantuka [Indonesia] 1557–1999 Macau [China] 1580–1586 Nagasaki [Japan] 17th century 1642–1975 Portuguese Timor (East Timor)1 19th century Portuguese Macau  • 1864–1999 Coloane  • 1851–1999 Taipa  • 1890–1999 Ilha Verde 20th century Portuguese Macau  • 1938–1941 Lapa and Montanha (Hengqin) 1 1975 is the year of East Timor's Declaration of Independence and subsequent invasion by Indonesia. In 2002, East Timor's independence was fully recognized.

North America & North Atlantic
15th century [Atlantic islands] 1420 Madeira 1432 Azores 16th century [Canada] 1500–1579? Terra Nova (Newfoundland) 1500–1579? Labrador 1516–1579? Nova Scotia

South America & Caribbean

16th century 1500–1822 Brazil  • 1534–1549  Captaincy Colonies of Brazil  • 1549–1572  Brazil  • 1572–1578  Bahia  • 1572–1578  Rio de Janeiro  • 1578–1607  Brazil  • 1621–1815  Brazil 1536–1620 Barbados 17th century 1621–1751 Maranhão 1680–1777 Nova Colónia do Sacramento 18th century 1751–1772 Grão-Pará and Maranhão 1772–1775 Grão-Pará and Rio Negro 1772–1775 Maranhão and Piauí 19th century 1808–1822 Cisplatina (Uruguay) 1809–1817 Portuguese Guiana (Amapá) 1822 Upper Peru (Bolivia)

• Armorial of Portuguese colonies
• Evolution of the Portuguese Empire
• Portuguese colonial architecture
• Portuguese colonization of the Americas
• Portuguese Empire in the Indonesian Archipelago
• Portuguese India
• Theory of the Portuguese discovery of Australia