Spanish navigation manuals and the English art of navigation
For most of the sixteenth century the books that taught England to navigate were Spanish: Enciso, Pedro de Medina and Martín Cortés in translation, behind them a Casa de Contratación that examined pilots and kept a master chart. The assessment used here is a British naval historian's — Cortés in Richard Eden's version was, on his reading, the most influential book after the Bible in English. The same paper insists the underlying invention was Portuguese and Spanish together.
Why this wins its question: English accounts of Elizabethan seamanship tell the story as a native awakening, and Spanish accounts of the same material tend to be reclamations written in Spanish and read by nobody outside Spain. The strongest available witness is neither: a British naval historian, writing for an international meeting, who states that the Casa de Contratación was examining pilots as strictly formulated routine half a century before England had a navigator, that the first English sailing directions and the standard English textbook were translations from Spanish, and that Eden's Martín Cortés was the most influential book after the Bible in the language. His paper is quoted here page by page — including its insistence that the invention was Portuguese as much as Spanish, and the objections three other scholars entered on the spot.
Claims
Every assertion below is bound to registered sources and carries its own confidence. Weight them; do not treat the page as uniformly authoritative.
The assessment used throughout this object is David Waters's paper "The Iberian Bases of the English Art of Navigation in the Sixteenth Century", printed at Coimbra in 1970 with the discussion that followed it. Waters was Deputy Director of the National Maritime Museum at Greenwich and the standard authority on English navigation of the period; the case for Iberian priority is therefore made here by an English naval historian rather than by a Spanish one.
Waters places oceanic navigation at the origin of the scientific method itself. Seeking the cause of the new "intellectual technique" of the fifteenth century, he finds one pre-eminent: "the need of seamen to be able to determine the position of their ship in the ocean", for which "solutions were first developed by Portuguese and Spanish scholars and applied by Portuguese and Spanish seamen". They were not complete, he adds, but sufficient to break European man out of the narrow compass of his known world.
The priority is joint, and Waters states the Portuguese half first and at length: the science of nautical astronomy was initiated under Prince Henry and had begun to be applied by 1460, the first recorded astronomical observation at sea being one of 1454 near the Gambia River. Any reading of this object that takes the achievement as Spanish alone is contradicted by its own source.
The Iberian institutional core was a Spanish office built on a Portuguese model. The Casa de Contratación was "established in Seville in 1503, on the lines of the older Casa da India in Lisbon"; in 1508 Ferdinand set up within it a hydrographic office and a school of navigation, where the latest discoveries were incorporated in a great master chart, the padrón real, supervised by a Piloto-Major. Within a few years the manufacture of instruments, their testing, and the examination of pilots to assess their competence as navigators "was a matter of strictly formulated routine".
Waters credits the Casa with an instrumental invention of the first order. It was behind the preparations for Magellan's expedition of 1519, and for it "an instrument of variation was especially devised for measuring magnetic variation of the compass at sea" — the invention of which he calls "of fundamental importance to hydrography and oceanic voyaging".
The Salamanca connection is explicit in the tables. The first known solar declination table for seamen, covering the four-year solar cycle, was probably the work of José Vizinho using tables prepared by the Hispano-Jewish astronomer Abraham Zacuto, part of his Almanack Perpetuum compiled from 1473 to 1478 at Salamanca and first printed at Leiria in 1496. Zacuto also prepared quadrennial solar declination tables for Vasco da Gama's voyage.
The printed transmission begins with a Spanish book. The first published Spanish navigation manual was written by "the scholar and lawyer Fernandez de Enciso and came out in Seville in 1519", republished in 1530 and 1546; it included the first derrota or Spanish sailing directions for overseas ever printed, and in John Frampton's translation, published in London in 1578, those became the first printed English sailing directions for overseas.
Pedro de Medina's Arte de Navegar of 1545 was, in Waters's words, "a masterpiece of exposition as it was of printing", with brilliant diagrams, clear tables and lucid text; translated into English and published in London in 1581 and again in 1595, it "became a standard English text book". Waters is careful that its pattern had been set by the Portuguese scholar Francisco Faleiro, writing in Castilian, whose Tratado del Esphera was published at Seville in 1535.
Knowledge moved by people as well as by print. Sebastian Cabot had been Pilot-Major of the Casa de Contratación for thirty years when the English Privy Council invited him over in 1548 to teach the English the art of navigation, at a time when "few, if any, Englishmen knew the art or had instruments, charts and books of navigation, none of which was obtainable in England"; he organised a navigation training ship, the bark Aucher, and soon had fifty or sixty English mariners trained as navigators.
The pivotal book was a translation commissioned by a working English pilot. Stephen Borough, Chief Pilot of the Muscovy Company, visited the Casa de Contratación in Seville in 1558 and came back admiring the training system that "for the last half-century had been turning out navigators competent to conduct ships over all the oceans of the world"; at his behest Richard Eden translated Martín Cortés's Breve compendio de la sphera y de la arte de navegar of 1551 as The Arte of Navigation, printed in London in 1561.
Waters's estimate of that book is the strongest claim in this object and is quoted rather than paraphrased: incorporating material from Enciso, Fernández and Medina and from the Portuguese pioneer works, it "can truly be said to have been the work which navigated English seamen to their meteoric rise to fame"; and "It was, in my view, probably the most formative, the most influential book after the Bible in the English language. More than any other it shaped the destiny of the English nation and of the English-speaking peoples which have sprung from their loins." The wording "in my view" is his own hedge and is kept here.
Dependence outlasted the Armada. Cortés's Arte of Navigation "was still being published in 1630"; as late as 1610 Edward Wright lifted in translation the whole of Zamorano's chapter on the plane chart, from his navigational manual of 1581, for the second edition of his Certaine Errors in Navigation; and of Bourne's Regiment of the Sea of 1574, the first English-written book on the art of navigation, Waters writes that "virtually all its material was of Lusitanian origin".
Some of the transfer was theft rather than translation, and Waters says so in the same paragraph. Drake, on his voyage round the world of 1577-80, "seized a Portuguese pilot, Nuno da Silva, for the passage to Brazil and down the east coast of America", and in the Pacific "seized the charts and rutters of two Spanish pilots bound for Manila", whom he released before he crossed the Pacific as they refused to navigate him.
Waters refuses the triumphalist version of his own thesis. He does not subscribe "to the view that it was ever easy, least of all for the pioneers, to invent ways and means to find the latitude and the time at sea in order", quoting Cortés on how difficult it is "to guyde a shyppe engoulfed, where only water and heaven may be seene"; and his conclusion credits "the Iberian invention in the middle of the fifteenth century, of the science of nautical astronomy" and "the technical skills developed in the resultant art of navigation by Portuguese and Spanish scholars and seamen" jointly.
The counterpoints entered by other scholars are printed with the paper and belong here. A. Cortesão restated the Portuguese case and corrected the conclusion to read "the English and the peoples of the whole world"; W. Washburn objected that speaking of the problem of longitude as solved is inaccurate without reference to the purpose served and the degree of accuracy achieved; and Ernst Crone noted that Medina was translated into Dutch in 1545 as well as into English, that later editions of Zamorano and of Bourne rest on Portuguese versions, and that the practical method of finding latitude by a double observation of the Sun was invented later by the Dutch mathematician Cornelis Douwes and used by navigators of all seafaring nations from 1750 to 1850.
What this object does not establish should be stated. It rests on a single scholarly paper of 1970, read in full but not set against later scholarship, none of which was reachable when this entry was written; and it is an argument about influence, not a bibliographical census. Editions, print runs and the actual reading of these manuals aboard English ships are not evidenced here.