VIANNA, Manoel José. [Manuscript portolan chart of the Atlantic Ocean including Western Europe, South America and West Africa]. Oporto, signed 'Manoel Joze Vianna a Fes no Porto', 1786.
Manuscript portolan chart of the Atlantic Ocean, extending from England to Argentina, from Newfoundland to the Cape of Good Hope, ink, wash and colours on vellum, maximum dimensions 860 x 680mm. The chart set within a red washed border, showing the detailed coastlines of eastern South America, western coast of Africa and western Europe north to Holland, sections of coast in yellow, green and red consecutively, principal regions in large script, coastal towns and capes in a small cursive hand, islands in various colours, dangerous rocky outcrops marked 'vegia' [i.e. 'vigia'], inshore shoals indicated, the chart decorated with flags in Brazil, Algeria and West Africa, Africa also decorated with a large view of the Portuguese Fort at La Mina, two half wind-roses, elaborate rococco floral motifs decorating South America and at head of the chart, detailed split graticule running down the Atlantic, equator and tropics ruled in with a full series of rhumb lines, the chart signed in a banner at the lower margin. (Two small areas, the Mediterranean and the western Atlantic, with water damage and loss, small section at upper neck similarly affected, a few light stains, one small hole and several abrasions to the margins, but otherwise fine.)
A VERY UNUSUAL, HIGHLY DECORATIVE, LATE 18TH-CENTURY PORTUGUESE MANUSCRIPT CHART in the style and presentation of a 17th-century Portolan. Although archaic in its concept, the chart is a statement of Portuguese interests in the world, particularly in Brazil. The draughtsmanship is skilled and accomplished, and the chart was probably drawn up for a prominent trader or noble family. Although the practice of drawing up sea charts on vellum had almost ceased by the 18th century as printed rutters and atlases took their place, there were a number of map-makers still working on vellum charts in this field in Spain and Portugal as late as the 1770s. The Library of Congress's Luso-Hispanic map collection includes several 18th-century Portolans on vellum, notably an Atlantic chart, similar to the present one, one of the early 18th century by Ferrera Manoel and another of the Atlantic dated 1633 by Roiz (cf. Nautical Charts on Vellum in the Library of Congress, 1977). All such charts are very rare, and this example by Vianna is particularly attractive.