4to, (206 x 156 mm). 122 ff. Later limp vellum, renewed flyleaves, spine lettered in ink, slightly soiled. Later ownership annotation ("D. Alekd. Padoani") on the title page and contemporary annotations in the margins throughout, lower corner of the first few leaves somewhat finger soiled, water stain in the lower outer corner of leaves 81 and 82, not affecting the text, otherwise in excellent condition.

‘Abraham Zacuto was one the most important geographers and cosmographers in the age of Columbus. His works were well known to Columbus, in Salamanca, and generally all over Europe’ Jews and the Americas. (JCB Jews and the Americas’).

Zacuto (1452-c.1515) served as Royal Astronomer to King John II of Portugal until his exile (following the expulsion of the Jews from Portugal) to Tunis, in the north of Africa. His astrolabe, astronomical tables and charts played a fundamental role in Portuguese and Spanish navigation to America and India, famously used by Vasco da Gama and Columbus, he is one of the men who help usher, in this case using science, Portuguese global expansion over the globe. After the expulsion of the Jews from Spain in 1492 he emigrated to Portugal accompanying his teacher the Rabbi Isaac Aboab. Zacuto´s reputation had preceded him and King Joao II of Portugal appointed him Royal Astronomer. Zacuto believed that it was possible to reach India by circumnavigating Africa, an idea that received Royal support. Joao II´s successor, King Manuel I made him the scientific adviser to the expedition that under the command of Vasco da Gama was organized to reach India by following Zacuto´s proposed route.

An interesting episode occurred during Columbus’ last voyage in February 1504, Colombus was threatened by hostile Indians in Jamaica and he resorted to Rabbi Abraham Zacuto´s Astronomical Tables to predict an impending lunar eclipse with which he succeeded in scaring them. Columbus was full of praise for the scientific works of Zacuto whom he had met in 1486. Zacuto gave him a manuscript copy of his astrological tables which Columbus always took with him on his voyages.

Zacuto also introduced Columbus to Don Isaac Abravanel, a Jewish notable with great influence at the Court, and he arranged for the navigator’s audience with the King and the Queen (v. http://www.zacuto.org/).

The first edition of Zacuto´s Almanach perpetuum was printed in Leiria 1496, a year before da Gama set off on his voyage. A single copy of that edition has appeared on the market in at least 100 years (for 1,600 GBP in the 1950’s, a huge amount), and one annotated copy of that edition by Columbus has been preserved in Seville.

Zacuto´s astronomical tables much improved the medieval Alfonsine Tables collected by order of the Castilian King Alfonso X the Wise in the 13th century.

As Geoffrey C. Gunn writes: Zacuto´s Almanach perpetuum ‘immediately helped to revolutionize ocean navigation. Prior to the Almanach, navigators seeking to determine their position in the high seas had to correct for "compass error" (the deviation of the magnetic north from the true north) by recourse to the quadrant and the Pole Star. But this proved less useful as they approached the equator and the Pole Star began to disappear into the horizon. Zacuto's Almanach supplied the first accurate table of solar declination, allowing navigators to use the sun instead.’ p. 98. Zacuto also instructed da Gama and his men in the use of an improved astrolabe which he had developed. This was an important adjunct to the tables and made the work of reading the measurements of the sun´s location anywhere more accurate. The navigators to Brazil and India also took Zacuto’s charts with them.

His disciple, Joseph (Vizinus) Vecinho, who was also Jewish, published his translation of Zacuto´s Hebrew text into Latin, under the title of Almanach perpetuum celestium motuum, of which two main variants exist of the preliminary l8 leaves, one in Latin and one in Spanish.

The importance for early navigation in the age of Discovery of this edition of Zacuto’s Astronomical Tables was ensured by the fact that it was printed in Venice, one of the main publishing centres in Europe, which guaranteed its wide dissemination. Vecinho's Spanish translation, transliterated into Hebrew characters and entitled Be'ur Luḥot Kevod Rav Avraham Zakkut was printed in Salonika in 1568. An Arabic translation of the Almanach is also extant in Milan (Ms. Ambrosiana 338). There were further editions printed Venice in 1502, 1525 and 1528.

When at the end of 1497 the Jews were also expelled from Portugal Zacuto moved to Tunis and later to Palestine and Damascus. Looking back from his exile with pride, Zacuto wrote: “I have been in the kingdom of Spain and in other Christian kingdoms when my books on Astronomy were published and people said [it is written by] R. Abraham Zacuto of Salamanca. I am entitled to be proud of it as our Sages said: “What is the wisdom that the Gentile nations appreciate?” and they meant the calculations of stars of Zodiac and of periods of time. I bear witness to heaven that they glorified [the people of] Israel for it”. In his historical narrative, Sefer ha-Yuhasin, (the Book of Lineage) he claimed: "My astronomical charts circulate throughout all the Christian and even Muslim lands.” (http://www.zacuto.org/#_ftnref17)

Zacuto success in fusing his mathematical and astronomical observations with practical aspects of oceanic navigation such as the preparation of sea charts and instruments vital for the most important navigators of the time undoubtedly makes him a major contributor to the creation of the world of today.

References:

Gunn, Geoffrey C., Overcoming Ptolemy: The Revelation of an Asian World Region (Lanham, Lexington Books, 2018)

Jews and the Americas: 165 Years of Collecting at the JCB Fall 2010 - Winter 2011 https://jcblibrary.org/exhibitions/jews-and-americas-165-years-collecting-jcb

J. Chabás and B.R. Goldstein, Astronomy in the Iberian peninsula: Abraham Zacut and the transition from manuscript to print (Transactions of the American Philosophical Society, New Series 90 (2), 2000).

Bibl. Hisp. No. 1060; Darmstadt LB: 33/7667; Panzer, VIII, p. 356 ; Brunet V, 1518.