João de Lisboa


João de Lisboa was a Portuguese explorer. He is known to have sailed together with Tristão da Cunha, and to have explored Río de La Plata and possibly the San Matias Gulf, around 1511-12.
The Brazilian historian Francisco Adolfo de Varnhagen erroneously stated that he was in Ferdinand Magellan circumnavigation voyage.
He is the author of a Treatise on the Nautical Needle, dated 1514, which is extant in a later copy included in an undated Portuguese nautical atlas.
He died in 1525 while traveling in the Indian Ocean.

Treatise of Seamanship

It is composed by the Brief Treatise on Seamanship and a "Treatise on the Nautical Needle found by João de Lisboa in the year 1514". Thereafter, an atlas of 20 charts follows.
The 20 charts present:
The book can be found in Torre do Tombo National Archive, with an additional information that the maps are made of parchment.
The maps of the Tratado clearly date from after 1514. For instance, it shows the Magellan Strait or Japan. On the other hand, the position of certain Portuguese flags is not consistent with historical events; in particular in one of the charts, Portuguese castles are drawn in Inca territory, something that was never reported in any official document. Based on the presence of Japan, Armando Cortesão dated the atlas as "circa 1560", while other authors date it to "circa 1550".