Détail sur la navigation aux côtes de Saint-Domingue et dans ses débouquemens. - Détail particulier pour la carte de la Gonave, ajoutée en 1788 au Pilote de l'Isle de Saint-Domingue

First edition of the Détail sur la navigation aux côtes de Saint-Domingue et dans ses débouquemens by the Comte de Chastenet-Puységur, printed in Paris by the Imprimerie royale in 1787. Title-page with a vignette of the royal arms of France, ornamental headpieces and decorated initials. The author's name, omitted from the title-page, appears on page [iii]. 2 unnumbered leaves, 81 pp. (Sabin 12235; Polak 1655, citing Maurice Chamonal's catalogue, no. 31).

Bound with the first edition of François Cyprien Antoine Lieudé de Sepmanville's Détail particulier pour la carte de la Gonave, ajoutée en 1788 au Pilote de l'Isle de Saint-Domingue, written while he was a first-class naval cadet and printed in Paris by the Imprimerie royale in 1788 (10 pp.; cf. Polak 6033; not in Sabin). Intended to accompany a newly surveyed chart of La Gonâve, this short work is frequently found bound after Puységur's Débouquemens. The John Carter Brown Library preserves a volume containing the same two works in a contemporary binding. Marginal sunning to the leaves of the second work.

Contemporary full mottled tan calf, the covers gilt-stamped at centre with the royal arms of France, surmounted by a closed crown and surrounded by the collars of the royal orders. Spine with five raised bands, decorated alternately with gilt anchors and fleurs-de-lis, burgundy shagreen lettering-piece, gilt fillets and ornaments, red edges. Joints split and reattached at head and foot, small loss to one corner of the lettering-piece, headcaps worn away and corners rubbed.

The royal arms, combined with naval anchors and fleurs-de-lis on the spine, suggest a binding intended for the official distribution of these sailing directions. 

Puységur's Détail was conceived as the textual companion to the Pilote de l'isle de Saint-Domingue et des débouquemens de cette isle, a hydrographic atlas published by royal order following the surveying voyage of the corvette Le Vautour in 1784 and 1785. The undertaking answered a pressing navigational need: to chart accurately the coasts and passages surrounding a colony whose commerce occupied a major place in the French Atlantic economy.

The débouquemens, the channels through which ships left the waters of Saint-Domingue for the Atlantic, were particularly hazardous. Strewn with small islands, shoals and reefs, they controlled the homeward routes towards France and the approaches to Môle Saint-Nicolas, a strategically important harbour at the north-western extremity of the island. The safety of an ocean crossing could therefore depend upon the accurate identification of a few narrow passages, where a navigational error might endanger both vessel and cargo.

A naval officer who had served during the American War of Independence, Antoine-Hyacinthe-Anne de Chastenet-Puységur (1752–1809) had also taken part in trials of marine chronometers, notably alongside Jean-Charles de Borda. Arriving at Cap-Français on 8 June 1784, he devoted fourteen months to surveying the coasts of Saint-Domingue and its surrounding passages. His work combined astronomical observations with longitude determinations obtained through marine chronometers, instruments whose development was then transforming the precision of hydrographic surveying.

In his Détail, Puységur presents the results of this campaign, describing anchorages, recording observed positions and reporting on the performance of the chronometers employed. The work thus supplies the practical instructions required to use the charts of the Pilote. The French National Archives preserve an extract from the Vautour's log for 1784–1785, while the Bibliothèque nationale de France holds a manuscript chart of the passages around Saint-Domingue, drawn and signed by Puységur in 1785 from his astronomical and chronometric observations.

Lieudé de Sepmanville's accompanying work represents a further stage in the same hydrographic undertaking. The island of La Gonâve, situated in the gulf that now bears its name, presented particular dangers to navigation. Following the loss of several royal and merchant vessels on the surrounding reefs, the Governor-General of Saint-Domingue, the Marquis de La Luzerne, commissioned the young officer in 1787 to survey the island. Lieudé himself records the circumstances of his appointment, stating that La Luzerne "jeta les yeux sur moi en 1787". His chart was added to the Pilote in 1788, together with the ten pages of explanatory text here bound with Puységur's sailing directions.

The successive publication of these two works illustrates the cumulative character of hydrographic surveying. A general reconnaissance of the coasts and channels was followed by a more detailed investigation of particular hazards revealed by navigational experience. Their association in the present volume, paralleled by other contemporary copies, preserves this close relationship.

On the eve of the French Revolution, these surveys reflect the scientific ambitions of the Royal Navy, which increasingly sought to replace knowledge transmitted through experience with positions established by observation and measurement. The accuracy of nautical charts was not merely a matter of geographical progress: upon it depended the safety of crews, the movement of ships and the commercial interests of the monarchy.

By the late eighteenth century, great maritime expeditions were no longer concerned merely with discovering the world: they increasingly sought to measure it. Beneath the arms of Louis XVI, these two works recall how the pursuit of precision had become one of the great ambitions of the French Royal Navy.