Du Breuil, Jean [Silvère de Bitainvieu]


Art universel des fortifications...

Imprint Paris, J. I Du Breuil, 1665

Military architecture

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Transcribed version of the text


     The author who wrote under the pseudonym Silvère de Bitanvieu was Jean Du Breuil (1602-1670), the son of Claude Du Breuil, a Parisian bookseller. After exercising his father’s profession, he entered the Company of Jesus. He became interested in architecture during the several years he spent in Rome.
L’art universel des fortifications françaises, hollandoises, espagnoles, italiennes et composées published in 1665 in the family workshop is, after La perspective practique (1642), his second book. The R P Jesuit chose to pose as a soldier with a good working knowledge of fortifications. This explains the choice of his pseudonym Silvère de Bitanvieu, an anagram of “iean du brevil iésvite” and the dedication of the book to Georges de Guiscard, in command of the Sedan border. He is addressing the sons of the nobility, to whom he wants to introduce military architecture, but he does not want to be taken as a teacher of theory alone, like his predecessors the Jesuit fathers, authors of treatises on military arts, such as Pierre Bourdin Le Dessein ou la perspective militaire..., 1655) and Georges Fournier (Traité des fortifications, ou Architecture militaire, 1648) for example.
Silvère de Bitanvieu wishes to provide the young noblemen who study at Jesuit academies with a clear and simple manual on fortification, claiming that he is a “man of experience and very much taken up with practical elements”. Nevertheless it is especially mathematics and their application to fortifications and the art of the siege which interest him. The plan of his work in six treatises shows the preoccupation of a teacher concerned with familiarizing nobles, destined to have a military career, with the art of fortification, allowing them to serve the king “as by right the nobility is obliged, more than all others” (preface). Conforming to classic reasoning in mathematics manuals aimed at nobles whose knowledge in this area is often rudimentary, he starts with definitions, followed by the twenty “General Maxims” which make for a good fortification. Not until the second treatise (traité II) does he approach the universal art of fortification which can be useful in all cases. He reduces it to four methods of fortification associated with four countries (France, Holland, Spain and Italy). Then the author gives a geometry and drafting lesson for drawing plans of regular fortifications with a ruler and a compass, which is he says in the preface, “very handy for the nobles who are quick to want to learn and put into practice, as I have often recognized”, whereas this affirmation is contradicted all through the book in repeated exhortations to the young nobles to work hard. In different forms he develops the recommendation found in the caption of Le Pautre’s engraving introducing this treatise :
            “The Ruler and the Compass, in the hand of a Warrior
            When he knows how to imitate this Illustrious Mistress
            With more accuracy have him
            Slice the Palm and the Laurel, on the champ de Mars”.
The necessary steps are the repetition of exercises in geometry, more than drafting, which, in fact, consists in “drawing lines”, associated with knowledge of the teaching of his predecessors, Jean Errard in first place for having been the first to make fortification an art. Then the reader can understand the four methods which, according to the author, summarize fortification, thanks to his simplified account and the calculation tables. The latter were not yey customary in works aimed at young nobles, which led the author to develop his thought in length in order to encourage them to read and use his text. Next he invites the reader to examine the plans, as the engineer knows how to do it, by indicating the method for “the elevation of plans according to simple perspective”. It is not the true perspective “at first difficult and not easy to practice” advocated by Descartes, but the one he described in his 1642 book La perspective pratique described in traité IV. At the end of this initiation into fortification, he gives the principal elements in attacking and defending strongholds, going back to the principles expressed previously in the specialized treatises. He does not give city plans, wishing to avoid “making the book bigger”. He refers to the plates by Christophe Tassin, the king’s geographer.
Therefore the book is a good manual for young gentlemen. Jean Du Breuil is aware that he must provide simple and precise information for, he writes, “this science is fine and loved by the nobility, who however do not become very much involved with Euclid”. So he gives details on the force of muskets or on the penetration of cannon balls but he does not want to encumber his readers’ heads with sine tables “which may be left to the mathematicians”. This book confirms the growing place taken by the teaching of mathematics applied to fortification in the training of nobles. It also confirms the recognition, during the 1660s, of the engineers with whom the author identifies himself when he claims to give the point of view of the professional who generalizes (universal art). The success of this book and of L’art de fortifier, de défendre et d’attaquer des places..., 1677, by R. P. Milliet de Chales contributed to systematize fortification, which would provoke bitter criticism from Vauban, refusing in the name of good sense and his wide experience this presentation of the “ways to”, in writing a propos of the rules, “One cannot be satisfied to apply them on indisputable principles regarding fortification if they are found to be contrary in practice and in the field”.
A second enlarged edition was published two years later in 1667, still at the family workshop. It was reprinted in 1668. A new edition, posthumous, appeared in 1674.

Michèle Virol (Université de Rouen) – 2011

Critical bibliography

F. de Dainville, "L’enseignement des mathématiques dans les collèges jésuites de France au XVIe et XVIIIe siècle (II)", Revue d’histoire des sciences, 1954, 7, 2, pp. 109-123.

K. Jordan, Bibliographie zur Geschichte des Festungsbaues von den Anfängen bis 1914, Marburg, Deutschen Gesellschaft für Festungsforschung e. V., 2003.

J. Langins, Conserving the Enlightenment, Boston, MIT Press, 2004.

M. D. Pollak, Military Architecture Cartography and the Representation of the Early Modern European City : A Checklist of Treatises on Fortification in the Newberry Library, Chicago, Newberry Library, 1991, p. 32.

H. Vérin, La gloire des ingénieurs, Paris, Albin Michel, 1993.