NUNES, Pedro.- PETRII NONII | Salaciesis, DE ARTE | ATQVE RATIONE NAVIGANDI | LIBRI DUO. | EIVSDEM in theoricas Planetarum Georgij Purba- | chij annotationes, & in Problema mechanicum Aristo | telis de motu nauigij ex remis annotatio vna. | EIVSDEM de erratis Orontij Finœi Liber vnus. | EIVSDEM de Cropuscolis Lib. 1. Cum libello Allacen de causis Crepusculorim. [gravura xilográfica com as armas de Portugal].- Conimbricæ: In ædibus Antonij à Marij, Vniuersitatis Typographi. Anno 1573.- [10], 201 [i. é 200], [2], 56, [2 br., 2], 63 [i. é 64], [3, 1 br.] p.: il.; 28 cm.- E. Pedro Nunes (1502-1578), born in Alcácer do Sal, of Jewish family, studied at the University of Salamanca; he was the main cosmographer of the Kingdom and professor at the University of Coimbra, having benefited from the protection of the Court, namely from the infants D. Luís, D. Henrique and D. Duarte, who were his disciples. According to Henrique Leitão, “De arte atque rationi navigandi”, published here for the first time, it is considered “the author's most important book and, therefore, the most important book of Portuguese Science”. Joint edition of four important scientific texts, the first two with consecutive pagination and a single common title page. The two remaining texts with independent title pages and pagination, show the particularity that the dates of the foot press were manually amended, at the time, from 1571 to 1573. Both have the indication on the face of “Secunda editio”. Copy missing the 6th preliminary leaf that should contain the errata and, on the verso, a representation of the compass rose; with slight browning and occasional slight tide stains. Face of the second part (De erratis...) slightly shorter. Circular stamp (±25 mm) erased on the three title pages, resulting in slight abrasion; minor restoration on the last sheet. Interesting ownership manuscript on title page, signed by Caspar Hersbach Agrippinas (Cologne printer and publisher), dated 1619. Recent binding, full canvas in shades of parchment. Anselmo, 861. BN (16th century), 523. Library of King D. Manuel II, 308, 310 and 311.