## Libro de algebra en arithmetica y geometria.

Antwerp: heirs of Arnold Birckman, 1567.

Exceptionally fine copy, bound in citron morocco for Jacques-Auguste de Thou (1553-1617), of this rare and celebrated treatise on algebra. “Considered the greatest of Portuguese mathematicians, Nuñez reveals in his discoveries, theories, and publications that he was a first-rate geographer, physicist, cosmologist, geometer and algebraist” (DSB). Only three other copies have appeared at auction in the last 50 years. J.A. de Thou assembled one of the greatest libraries of his time. Thou’s library later became the property of Jean-Jacques Charron, marquis de Ménars (1643-1718) before being sold off in 1789.

❧Frank Streeter 392; Macclesfield 1548; Honeyman 2354; Peeters-Fontainas 845 (this copy).

“Both as Royal Cosmographer under King John III (the Pius) of Portugal and as professor of mathematics at the University of Coimbra, Nuñes gave instruction in the art of navigation to those associated with Portugal’s merchant and naval fleets. His *Libro de algebra* provided the mathematical underpinnings of that instruction — and much more — adopting Pacioli’s abbreviated notational style and treating the solution not only of linear and quadratic equations but also that of a cubic equation of the type *x ^{3} + cx = d* following the spectacular mid-sixteenth-century work of the Italians Niccolo Tartaglia and Girolamo Cardano” (Katz & Parshall,

*Taming the Unknown*, p. 205).

The book is in three parts. The brief first part deals with equations of the first and second degree, drawing directly from the work of Luca Pacioli and the

*maestri d’abbaco*. The longer second part deals with the theory of ratio and proportion, and explains the handling of roots and polynomials. The third and longest part deals with equations of the third degree, following Tartaglia and Cardano, and contains a large collection of arithmetical and geometrical problems and their solutions.

For a detailed account of the contents of the work, see Antoni Malet, Changing notions of proportionality in pre-modern mathematics, pp. 193-6 (academia.edu/2237488/Changing_Notions_of_Proportionality_in_Pre-Modern_Mathematics).

8vo (167 x 104 mm), ff. [xvi], 339 (recte 341), woodcut printer’s device on title, woodcut diagrams in text. Early 17th century French citron morocco, all edges gilt, spine tooled in compartments with de Thou’s final monogram, covers with three-line roll border and in the centre the combined arms of de Thou and his second wife Gasparde de La Chastre. Very fine and clean. An outstanding copy in first-rate condition of this rare and important book. Custom vellum slip case.

Item #3645

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Price:
$35,000.00
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