“F. d. V: P.”

Mémoire sur Cayenne.

Cayenne, French Guyana, 1783.

Manuscript on paper, folio (ca. 31 x 20 cm), [44] pp., written in brown ink, with heavy authorial reworking throughout; several pages with substantial struck passages and rewritten paragraphs; occasional sectional headings (e.g. on “front des bastions …”), and lists of artillery “pièces” with totals.

Sewn.

An important detailed military-engineering report on the topography, hydrography, approaches, and fortifications of Cayenne, with proposals for reform and artillery dispositions; written in French in a clear eighteenth-century cursive hand, extensively revised in the course of composition (numerous cancellations, interlinear corrections, marginal notes, and bracketed insertions), and signed at the conclusion with the initials “F. d. V: P.”; dated internally 22 janvier 1783.

A substantial, technically sophisticated mémoire on Cayenne composed at the end of the American War of Independence, integrating (i) coastal and riverine observation (mudbanks, tidal effects, channels, and the instability of coastal features), (ii) a strategic reading of terrain and approaches, and (iii) a professional critique of the enceinte and outworks according to Vauban-derived doctrine (bastions, courtines, glacis, chemin couvert, lunettes, retranchements, embrasures, enfilade and plunging fire, communications, and the hydraulic management of ditches). The author’s method is diagnostic and prescriptive: he repeatedly measures Cayenne’s defensive system against the requirements of an “attaque régulière,” and argues that piecemeal works are ineffective without an integrated scheme of mutual support, protected communications, and properly disposed artillery.

Particularly noteworthy are: (1) the memorandum’s consistent emphasis on hydrography and tides as operational variables (rather than mere descriptive geography); (2) the combination of local environmental constraints—soft ground, shifting banks, channels and river mouths—with formal fortress geometry; (3) repeated attention to the Savane, Montabo, and other dominant ground, and the consequences for fields of fire; and (4) a structured programme of improvements, including revised positions, stronger exterior works, and a quantified artillery scheme culminating in a summed total of pieces (one section totals 26 pièces).

The manuscript is also significant as evidence for a continuing “mémoire” tradition on the defence of Cayenne in the late eighteenth century, attested in French military archives. The Service historique de la Défense preserves a separate “Mémoire sur Cayenne” of 1785, described as 38 pages and accompanied by a Bellin engraved map dated 1763, indicating the existence of comparable professional reports circulating within military record series. The ANOM catalogue likewise records a later “Mémoire sur Cayenne” “relatif à la défense de la colonie” attributed to Jean René Guérin de Foncin (capitaine du corps royal du Génie), demonstrating institutional continuity of the genre and the association of Cayenne defence reporting with Corps du Génie personnel.[1]

Historically, the mémoire belongs to the late Ancien Régime phase of defensive reassessment in Guyane, during the period of Governor Bessner (early 1780s), when metropolitan and colonial authorities were attentive to coastal vulnerabilities and the reorganisation of colonial infrastructure. While attribution remains unresolved here (the signature is abbreviated), the technical lexicon and analytical posture identify the author as a trained military engineer writing in an official-advisory capacity, rather than as a traveller, administrator, or planter.

This is, in short, a rare, unpublished engineering assessment of Cayenne’s defensive system at a pivotal moment, valuable both for the history of French colonial fortification and for environmental/topographical military history in the Guiana region.

Condition: generally very good and legible, light soiling and occasional spots; paper sound.