Sailing School: Navigating Science and Skill, 1550-1800. Margaret E. Schotte. 2019.

Sailing School: Navigating Science and Skill, 1550-1800. Margaret E. Schotte. 2019.

Schotte, Margaret E. 
Sailing School: Navigating Science and Skill, 1550-1800
John Hopkins University Press. 
ISBN 9781421429533. 
295 pages. 


Margaret Schotte’s well-researched and richly-illustrated book is a study of how print materials and traditional hands-on-practice, along with instru­ments, were used to train navigators.  How did navigators learn their skills?  How did they become competent navigators, indeed “highly skilled technicians?”  How was new detailed information (which she terms theoretical science) “developed, codified, and transmitted?”  The book describes how “a traditional craft was transformed into an applied science” from the 16th through the 18th centuries. 


This trans-national study covers training schools and published materials, with examples from Spain, France, the Netherlands, and England.  Print materials are the central focus.  Perhaps the book’s greatest contributions are its identification and examination of published European textual materials (charts, nautical manuals, astronomical tables and mathematical tables), and how these printed materials (produced by the availability of the printing press after the 15th century) impacted navigational training and education.  The book also examines how classroom learning and training on a ship’s deck (theory and practice) were put into use by those responsible for training navigators. 


The book considers navigational education in Seville, Spain (c. 1552), Amsterdam, The Netherlands (c. 1600), Dieppe, France (1675), London, England (c. 1683) and, again, Amsterdam, (c. 1710). 


Lieutenant Edward Riou is featured in one chapter to show how his training was put to a test in the Southern Indian Ocean.  A concluding chapter, titled “Sailing by the Book”, summarizes the ebb and flow of training by theory and practice, and the importance of printed materials.  Fully one-third of the book comprises a glossary of terms, notes, and an index.


I will provide a glimpse into some of the examples cited by the author regarding the evolution of navigational learning by theory and practice. 


At Seville, the Spanish crown sponsored a school, Casa de la Contratacion, the “House of Trade”.  All aspirants to be a master navigator were examined by Spain’s first piloto mayor, Amerigo Vespucci (1454-1512).  Students applied to be instructed in a classroom, and then sat for an exam.  They learned cosmography (a mixture of geology, astronomy, and geography) based upon manuals by Martin Cortés (a humanist), and by Pedro de Medina (a crown navigational consultant), books that were the standard for many years.  Training focused on forming a mental picture of the earth.  Concepts such as the pole, equator, azimuth, celestial spheres, the heavens, seas, winds, the sun, magnetic compass, the moon and tides were features of this classroom schooling.  Astronomical tables for the sun and the stars allowed calculation of latitude.  Tables led to calculation of the rotation of the Pole Star applied to navigation.  The use of rhumb lines (loxodromes) in navigation were studied.  They are lines that cross meridians at the same angle to indicate the path a ship was to follow on a constant compass bearing.


At Amsterdam, the Dutch East India Company required navigators to sail beyond the sight of land (Large Navigation), a situation similar to that in Portugal and Spain in the later 15th and 16th centuries.  Dutch voyages tripled in their length; safety in navigation remained paramount.  This required literate sailors who were trained in mathematics.  Navigators were needed to shift attention from land to the sky since, as Schotte writes, 

the sun and stars increasingly served as both clock and compass.  Navigating had always required an excellent memory – for local coastlines, shoals and reefs, shifting coastal currents and fluctuations of high tides, and the types of tacit skills that had been passed down person-to-person for centuries – but the process now increasingly demanded a head for numbers.


A vessel’s captain was in charge of the ship, but he was guided by navigators.  The accurate calculation of latitude and longitude was essential.  The difficulties in determining longitude led to the development of different methods for finding it, none of which were satisfactory or were simple enough for easy computation.  A possible resource to assist navigators was the sea chart, in which navigators recorded a vessel’s progress on the high seas.  However, charts required elaborate tables that tested both theory and practice to an unsettling degree.  Gerard Mercator’s map with gradated pro­jection (1569) accounted for decreasing distances at the poles.  Maps, however, required use of detailed tables which lessened their practical use at sea.  In Amsterdam, Ezechiel de Decker published in 1631, The Practice of Large Navigation, with logarithmic and trigonometric tables.  The early 17th century witnessed the publication of an increasing number of nautical manuals, as well as the introduction of formal classroom instruction interspersed with practical hands-on training.  There was a demand for more technical publications, and for books for the keeping of logs, journals, mathematical and astronomical tables.


The author takes readers to the bookshop of Cornelius Claesz in Amsterdam, the Netherland’s most important marine and navigational bookseller, and identifies resources newly-available in the early 17th century.  While Spanish publications focused on astronomy and cosmography, Dutch authors focused on calculation of tides, given the North Sea’s shallow coastline and strong tides—much less of an issue for Iberian navigators.  The author provides an explanation and examples of how the “rule of thumb” (and memorized rhymes) were used as devices to recall the “Golden Number”, the current year’s place in the nineteen-year lunar cycle, and to allow the calculation of the epact (the difference between lunar and solar calendars) that helped determine the tides for a particular port.


Dieppe was the centre for 16th century cartography.  Schotte focuses on French Abbot Guillaume Denys (c.1624-c.1689), who, she identifies, “was at heart a mathematician, convinced of the power of numbers and rules and confident that they could improve a sailor’s day-to-day practice at sea”.  Denys headed the Royal Navigational School for a half century, training hundreds of mariners.  He had a connection to Navy Minister Jean-Baptiste Colbert (1619-1683), who also served Louis XIV as finance minister for over twenty years.  Denys introduced trigonometry and logarithms into navigational training.  Among his publications was L’Art de Naviger par les Nombres… (1683).  It introduced trigonometry into French navigational education, and allowed the solving of an equation with two unknowns.  It took the view that

navigation is nothing more than a right triangle.  The boat’s point of origin, its point of arrival, the direction of travel, and the distance covered could readily be configured into a triangle, often with a right angle to simplify computation.  If a mariner knew any two components of this ‘sailing triangle’, trigonometry would help him figure out the other two in terms of latitude and longitude. 


Moreover, the lines of the triangle could be either straight or curved. 


Navigational training in England in the 1680s was not only based on astronomy (understanding a ship’s place in relation to the stars) but was infused with mathematics, similar to the France of Abbot Denys or 17th century Dutch training.  As England’s colonial activities intensified in the American colonies, the Caribbean and India, so did the need for long-distance navigational training.  A growing number of publications helped address this need.  Mathematics began to take precedence over astronomy at the Royal Mathematical School as well as at the Admiralty, often led by men with multiple ties to the Navy Board, the Royal Observatory, and the Royal Society.  The diarist Samuel Pepys (1633-1703) is one example.  He served as a naval administrator, and as an active board member of the Royal Mathematical School.  One of his contributions was to advocate the use of instruments (applied techniques) as being equal to, or more important, than mathematical theory. 


In England and elsewhere, there was much discussion and disagreement about the best way to learn: instruments, geometric calculations, or numerical tables?  Some said physical instruments were the key to practical hands-on training, allowing theory and practice to reinforce each other in navigational training.  Some instructors were hired to teach in ships, an example of theory reinforcing practice (or vice-versa). 


I suspect that for many Cook enthusiasts, the most interesting part of the book deals with Lieutenant Edward Riou’s voyage in Guardian on her way to Australia.  Riou (1762-1801) had previously sailed as a midshipman in Discovery during Captain Cook’s Third Voyage.1  Guardian carried 120 men, 25 of whom were convicts, as well as provisions, for the penal colony at Botany Bay.  On 24 December, 1789, she struck the submerged part of an iceberg 400 leagues (1,200 nautical miles) south of the Cape of Good Hope, in the vicinity of the two Prince Edward Islands (Prince Edward and Marion [du Frense] Islands) that he and Cook had sailed past in late 1776, on their way to the Crozet and Kerguelen Islands.  Guardian’s predica­ment is reminiscent of Endeavour’s striking of the Great Barrier Reef in June 1770.  Riou’s situation included manning (and repairing) pumps, fothering the vessel, as well as his active direction and encouragement to the ship’s company. 


Throughout the ordeal, Riou did not abandon his theoretical tasks of making observations, recording weather and rough seas, making scientific observations, and fretting that the rough weather would lead to inaccurate calculation of longitude.  Due to Guardian’s low vessel rating, she did not carry a chronometer.  Assuming that Guardian would be lost, her three-dozen passengers departed in the small boats from the disabled vessel.  Riou and some of the ship’s company stayed with Guardian.  Riou managed to keep Guardian afloat, and, after two months, was in sight of Table Bay on 21 February, 1790.  Riou carefully plotted the remaining distance to land, avoiding the treacherous False Bay.  One of the cutters had reached Table Bay a few days earlier, its crew having been rescued by a passing French ship, leading to the premature announcement that Guardian was lost.  Riou was promoted to captain and proclaimed a national hero.  Guardian, however, was no longer serviceable.


Why did Riou and Guardian survive?  Riou studied the standard textbooks at the Royal Mathematical School.  As an officer he employed both new as well as traditional navigational techniques.  The author explains that Riou was a persuasive commander, especially prevailing upon the company to man the pumps for many days, “despite failing equipment and flagging spirits”.  He developed alternative means to steer the vessel after the iceberg destroyed the rudder.  Most importantly, Schotte adds, Riou had “a deep familiarity with the art of navigating”.  At age 26, he was adept at “making both accurate observations and reasonable dead-reckoning estimates under difficult circum­stances”.  He and his men manipulated ropes to bring Guardian around when she veered off course, not easy considering the variations in weather and the conditions of the ocean.  Riou wrote that his entire thoughts were on “navigating and fothering”.  Schotte feels that “Ultimately, Riou drew upon the practical and theoretical knowledge he had accrued over the preceding fourteen years – coupled with more than a little luck – to save sixty men’s lives”.  The episode was recaptured on the stage (and by ballad) for years thereafter. 


Riou’s log books show a balance between theory and practice, the skills and techniques that made up his navigational training and its use on the high seas.  Schotte provides examples from them, with both calculations and sketches, as well as a manuscript workbook from the time when he was a young navigator.  The author concludes, “To a large extent, Riou treated each day’s activities as a scientific enterprise”.  Her analysis of Riou’s Guardian episode is very well-done.


Captain James Cook appears in Schotte’s book only through general references, mostly in relationship to Riou’s sailing.  It is disappointing that Cook, one of the greatest navigators of the late 18th century (and for all time), was not given serious consideration in this study. 


Schotte’s book is a valuable academic study.  Sailing School is well-written with copious documentation.  The author has clearly identified much Spanish, French, Dutch, and English navigational material published from the 16th through the 18th centuries.  Many of these are depicted in the book’s frequent illustrations, mostly in greyscale with a few in colour.   Schotte describes the various processes by which navigators learned how to sail.  She asserts that the availability of printed materials “changed the larger arc of a sailor’s career”.  Books were valuable in training, and useful references on the high seas, which is why Schotte stresses that print materials “transformed” the lives of seamen throughout Europe.


I found the glossary useful, but sometimes I also needed to look elsewhere to understand technical terms.  As a source to understand how navigators were trained by theory and practice and the role that published materials played in producing competent navigators, this book is a useful reference.  I think it will be most helpful for a somewhat limited audience, especially readers with a knowledgeable maritime background.


James C. Hamilton




  1. Cook’s Log.  2011.  Vol. 34, no. 2.  Page 47.    

Originally published in Cook's Log, page 15, volume 43, number 1 (2020).

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