João Faras


Mestre João Faras, better known simply as Mestre João, was an astrologer, astronomer, physician and surgeon of King Manuel I of Portugal who accompanied Pedro Álvares Cabral in the discovery of Brazil in 1500, and wrote a famous letter identifying the Southern Cross constellation.

Background

The celebrated 1500 letter of Mestre João Faras was discovered in the Portuguese royal archives by the historian Francisco Adolfo de Varnhagen, and published for the first time in 1843.
Despite much search, the figure of Mestre João Faras remains elusive. In his 1500 letter, Mestre João identifies himself simply as a bacherel of arts and medicine and a personal physician and surgeon of the King Manuel I of Portugal.
Besides the 1500 letter, the only other concrete clue we have of Mestre João's existence is an manuscript translation of Pomponius Mela's De Situ Orbis from Latin into imperfect Castilian. He may also have gone by the name 'Johannes Emeneslau'.
On account of his poor command of Portuguese and penchant for Spanish, Mestre João Faras is generally believed to have been originally of the existing nationalities in what would be Spain later. He was almost certainly a Sephardi Jew. He probably fled Spain for Portugal after the 1492 Alhambra decrees, but ended up converting after 1496, to enter the service of King Manuel I of Portugal.
Recent researches have traced at least two original Spanish Jews who plausibly fit his profile: one, a certain Juan Faraz, a native of Seville, another, a "Mestre Joam", who settled in northern Portugal and took up the name João da Paz.

Voyage and mission

Mestre João Faras joined the 2nd Portuguese India Armada of thirteen ships, commanded by Pedro Álvares Cabral, which left Lisbon in March 1500, destined for Calicut, India. It is unknown on which ship he sailed, although it has been conjectured to be either the Anunciada commanded by Nuno Leitão da Cunha or the São Pedro commanded by Pêro de Ataíde.
The purpose of his joining the expedition seems to have been purely scientific, to assist the future development of navigational science. His predecessor Mestre José Vizinho was sent to Guinea back in 1485 to test measurements of solar altitudes. Mestre João Faras was probably sent by the king in a similar spirit, to test out new astronomical instruments and tables. It is known that Mestre João Faras brought along a new nautical astrolabe and what he characterized as some new-fangled Arab astronomical nautical staves for experimentation. He was almost certainly furnished with Abraham Zacuto's new tables as well.
Mestre João Faras was probably specifically charged to find a way of determining the position of the ship by the stars in the Southern Hemisphere, a difficulty which had not yet been overcome. Since the time of Prince Henry the Navigator, "compass error" could be corrected in the northern hemisphere by recourse to the position of northern Pole Star, thus allowing navigators to determine the correct position of the ship. But the Pole Star disappeared beyond the horizon as the equator was crossed, rendering this method useless in the southern hemisphere. It was hoped that an equivalent South Pole Star might be found.
An alternative method was to take recourse to the position of the sun at noon. This had been suggested since at least the 1470s, but was really only opened up with the publication of the Almanach perpetuum of Abraham Zacuto in 1496, with its tables of solar declination. As the sun could not be observed directly by the quadrant, Portuguese navigators brought on board ship the old land-based astrolabe. Unfortunately, astrolabe readings required stability which is not possible at sea, so new small hand-held nautical astrolabes were being experimentally introduced at this time.
This was still not perfected. In 1497, Vasco da Gama took Zacuto's tables and the astrolabe with him on the maiden trip to India, but was dissatisfied with results. Upon arrival at the Bay of St. Helena in November 1497, Gama disembarked to take readings on land because he did not trust the readings of the new nautical astrolabe at sea. Master João Faras makes much the same complaint about his on-board readings in his letter - claiming the rocking of the ship put his readings off by a whole four or five degrees.

In Brazil

On 22 April 1500, Cabral's armada sighted the land coast of Brazil, and anchored a couple of days later at Cabrália Bay, where they were met by local Tupiniquim Indians.
Master João Faras left the ships on April 27, and with the assistance of the pilots Afonso Lopes and Pedro Escobar, set up a large wooden astrolabe on the beach with the objective of taking the altitude of the sun at mid-day and determine their position. The latitude measure calculated by Faras on April 27, 1500 was 17° S.
Mestre João Faras assumed they had landed on an island. Indeed, he believed these islands were already discovered and depicted on earlier maps, but not known to be inhabited. In a curious passage of his letter, Mestre João advised the king to consult an old mapa mundi then in the possession of the Portuguese navigator Pêro Vaz da Cunha in Lisbon, which depicted these very islands.
Mestre João Faras's conclusion that they were on an island was probably shared by Pedro Álvares Cabral and certainly by the secretary Pêro Vaz de Caminha, who wrote up the official report..
On May 1, 1500, both Pêro Vaz de Caminha and Mestre João Faras wrote up their separate letters to King Manuel I of Portugal, signed from the location of Vera Cruz. Both letters were given to the captain of a ship to be sent back to Lisbon. The armada left Brazil in the direction of the Cape of Good Hope on May 3, 1500.
In his letter to the king, Mestre João Faras provided a rudimentary sketch of the stars of the southern hemisphere sky, in an attempt to identify the Southern Pole Star, although he apologized to the king for not having taken their precise height measurements. He identified the five-star constellation now known as the Southern Cross, but he then called "las Guardas", as they were always bright and visible above the horizon. But he recognized they were not the elusive pole star of the south. Instead, he tentatively pointed out two lower stars. He rounded off his letter in a pessimistic note, suggesting that it was probably better for ships to continue trying to navigate by the altitude of the sun, rather than hoping to find the Southern Pole Star with a quadrant.
Although historians generally credit Mestre João Faras as the "discoverer" of the Southern Cross constellation, some point out that he might have been preceded by the Venetian navigator Alvise Cadamosto, who, sailing at the mouth of the Gambia River in 1455, drew a similar constellation which he called the carro dell'ostro. However, Cadamosto's constellation has too many stars and is positioned incorrectly.
Nothing more is heard from or about Mestre João Faras after this letter.
According to one author, 'João da Paz' settled in Porto, Portugal. A search in the 1518 household roster of King Manuel I shows nobody by that name, suggesting he was probably already dead by that time.