Carolo Eendero - Traite du Compas de Proportions - 1695

Powder, Geometry, and Fire: A Secret Manual for the Artillerymen of the Seventeenth Century
An interesting technical treatise published in Bruges in 1695 by Leonard Vande Walle, dedicated to the use of the compass of proportion and the updated techniques of modern artillery, a military discipline that combined applied geometry and ballistic science. It is one of the rare printed testimonies on the transmission of technical knowledge in French-speaking Northern Europe at the dawn of the 18th century.
Market value
Extremely rare on the market. No copies have been detected in the major international antiquarian databases. Its combination of rarity, historical significance, and editorial area makes it of the highest interest to collectors and institutions specializing in the history of science and military engineering.
Given the extreme rarity of the volume — with no copies listed in international databases (ICCU, STCN, USTC), no recent auction appearances, and high collector interest in pre-Enlightenment technical-military treatises — the estimated market value for this specimen can be roughly between 6,500 and 9,000 euros, with higher figures if it features a contemporaneous binding in good condition, all original plates, and a significant bibliographic provenance.

Physical description and condition
Full leather binding. Spine with signs of wear. Numerous plates outside the text, folded. Internally pages slightly browned, overall good condition. Pp. (2); 20 unnumbered; 199; 6 unnumbered; (2).

Full title and author
New Treatise on the Use of the Proportional Compass and Practice of Modern Bombardment.
In Bruges: at Leonard van de Walle 1695.
Carolo Eendero.

Context and Significance
The treatise represents one of the earliest and most comprehensive French-language expositions on the practical use of the compass of proportion, a tool developed during the Renaissance to facilitate geometric and military calculations. The text also includes precise notions of ballistics, fortification construction, and artillery, fitting within the tradition of military technical-scientific literature of the period, akin to the writings of Tartaglia and Galileo. The work testifies to the circulation of mathematical knowledge among the academies and arsenals of post-Renaissance Europe.

Author's biography
Carolo de Eendero was a noble from Bruges, in the Flemish region.
In 1695, he published in Bruges his treatise titled 'Traité nouveau de l’usage du compas de proportion, et pratique de la bombarderie moderne,' published by Leonard van de Walle. The volume is divided into two parts:
The first treatise discusses the compass of proportion; the second presents a dissertation on ballistics, particularly the firing force of cannons, studied until the 19th century within the scope of French artillery.

Scientific and military significance
This is one of the earliest French-speaking illustrated texts concerning the practical application of the proportional compass and modern artillery techniques. Its impact extended to the artillery of the French army, between the 18th and 19th centuries, thanks to the ballistic principles outlined in the treatise. Leonard Vande Walle, a typographer and bookseller active in Bruges, was known for publishing technical and religious texts in the late Seventeenth century. This treatise is probably the result of collaboration with an anonymous military author, an expert in military engineering.

Printing history and circulation
Printed in Bruges in 1695, the volume is extremely rare and scarcely represented in public collections. It does not appear in standard catalogs such as Brunet, Graesse, or STCN. Vande Walle's typography had a brief duration but was distinguished by editorial quality and attention to specialized themes. The work falls within a scarce Flemish scientific-technical typographic production from the late 17th to early 18th century.

BIBLIOGRAPHY AND REFERENCES
No censored copies in ICCU, STCN, or USTC. Not in Brunet or Graesse. Indirect citations in local Flemish bibliographies and in repertories on the history of ballistics (see secondary bibliography of Duplessis, Les instruments mathématiques aux XVIIe-XVIIIe siècles, 1893).