Military

MILITARY

Early modern military engineering co-evolved with the siege tactics that characterized European warfare from the late fifteenth to the mid-eighteenth centuries. By 1530 the assimilation of heavy gunpowder weapons was matched by the development of fortifications that could withstand cannonball bombardment. Campaigns usually focused on the taking of a city, although an aggressor's single most potent tactic was often to starve the inhabitants. Early modern siege warfare, precisely because of its relatively static, game-like quality, offered a broad stage for the activities of the engineer. Opportunities abounded for engineers who could maximize the capabilities of machines and gunpowder, effectively organize the immense workforce of trench diggers, ease the enormous burden of siege train baggage on campaign, or design an "impregnable" fortress in peacetime. As military engineers sought to define a science at the core of their new profession, the sphere of military engineering opened up an avenue of advancement both for men and for ideas about how the world of resisting walls and projectiles—matter and motion—worked.

THE NEW WEAPONS

Gunpowder weapons were known to Europe by the 1320s. The earliest "cannons" were usually large barrel- or pot-like receptacles made of forged metal, mounted on a cumbersome cart and charged with irregular balls or projectiles. By 1500 most of the innovations that were to determine the form of muzzle-loaded cannons had been introduced. Cannons were cast of bronze (and, shortly thereafter, iron) to specific lengths and calibers. These ranged from the very smallest falconet, at a barrel length of six feet and a caliber of just over two inches, to long slender culverins, to heavy four-ton cannons. (Mortars and, later, howitzers were also cast.) They were then mounted on specialized carriages on pivots (trunnions) that were placed at standardized distances from the rear of the cannon. Indeed, the invention of standardized trunnions, with the increased ease of aim and accuracy they allowed, has been credited as the secret behind the terrifying reputation of Charles VIII's artillery when in 1494 the French monarch swept through Italy from the Alpine border to Naples.

Even given the impressive advances of the sixteenth-century cannon over its precursors, cannons still presented numerous difficulties that added to the inherent unpredictability of warfare. Each cannon was unique, owing to inconsistencies in metallurgy, boring, and other factors of its production. Cannons shot differently, depending on the gunpowder and how hot they became. They might crack in battle or, worse, explode prematurely if they were handled improperly. The heaviest bombards required dozens of draft animals to haul them; legions of men, employed to maneuver and plant cannons, attended the artillery train.

Innovations in the design of ordnance that might ameliorate these conditions were usually owed to gun makers. Members of the Alberghetti family, for example, requested numerous patents over the generations in which they headed the foundry at the Venetian arsenal. The single greatest improvement to the cannon was effected by the boring machine invented by Jean Maritz (1680–1743) in the mid-eighteenth century. The cannon barrel was rotated by a machine powered by horses, while a bit was advanced into the front of the piece. Before this time, cannons were each cast in a unique mold with an earthen core to make the hollow. The hollow tube was then smoothed on a vertical reaming machine. The boring machine allowed many cannons to be cast from the same mold, thereby helping to standardize shots among cannons. Moreover, because the bore could more precisely fit the size of the cannonball, it nearly halved the space between the inside wall of the barrel and the cannonball moving through it (windage). This greatly increased accuracy and power.

MILITARY ARCHITECTURE

While a number of gunfounders, or their sons, became military engineers, the profession was much more rooted to the tasks of the Renaissance city architect. Architects had traditionally acted as the designers of fortifications and military machinery. Filippo Brunelleschi (1377–1446) had to take time off from the construction of the Duomo in Florence in order to follow troops at war with the nearby city of Lucca. Architect, engineer, painter, and sculptor Francesco di Giorgio (1439–1501) is credited with the development of one of the most important innovations in defensive architecture, the angled bastion on which effective defensive fire could be mounted; Michelangelo (1475–1564) further developed its offensive capacity. Among the most active workshops in fortifications design were those of Antonio da San Gallo the Younger (1485–1546) and Michele Sanmicheli (1484–1559).

In the context of the decades-long Italian wars (1494–1559), in which huge armies and their siege trains battered Italy, the style of fortification that would dominate continental European warfare for the next two centuries emerged. Italian architects developed the main features of the trace Italienne, a polygonal circuit of walls with spade-like bastions built at each angle, by the early sixteenth century. The tall, crenellated walls of medieval fortifications had offered little resistance to cannon. Lower, thicker walls, reinforced by piling dirt against them (the "scarp," which was sometimes faced with masonry) better deflected and absorbed cannonballs and permitted the use of defensive cannon fire. Bastions provided a platform for cannons that allowed defenders to rake the curtain walls with fire (enfilade) and cover neighboring bastions. By the middle of the century, platforms in the curtain walls ("cavaliers") were added so that defenders could enfilade bastion walls, or fire into the bastion should it be taken by the enemy; a low flat wall outside the surrounding ditch, but fitted with parapets ("covered way"), enabled defenders to reconnoiter the activities of attackers and served as a staging area from which to conduct sorties.

In the course of the following 150 years, the depth of defensive works was developed enormously. Maurice of Nassau, prince of Orange (1567–1625), under the tutelage of the mathematician Simon Stevin (1548–1620), developed further outworks, particularly the ravelin, a fortified point that offered more angles for defensive fire outside the main walls. Fortification designs increasingly resembled star patterns, with a series of ditches, berms, and angled ravelins radiating from the polygonal perimeter of the city walls. The concern for depth of defensive works continued in the French corps of engineers and was brought to a baroque height by the followers of the great military engineer Sébastien le Prestre de Vauban (1633–1707).

Early modern fortifications systems were meant to act as a machine, each part interacting with another. By the onset of the seventeenth century, especially as the focus of European war was then centered on the struggles in the Netherlands, where broad flat land offered an empty canvas for the geometrical designs of engineers, the fortress was designed to take advantage of every possible angle from which any conceivable weapon could be employed. Built into the construction of a town wall and its outworks were plans for every foreseeable method of approach and point of breach by an enemy. Fortifications were tactics, but tactics that operated through a knowledge of mathematics, construction, and gunnery.

ON CAMPAIGNS

If, ideally, the role of the engineer in fortifications was to build into his design a retort to any plan of attack, the role of the engineer in the field was to alter the methods of attack in an unexpected and more efficacious way. It is for this reason that Vauban's most significant contribution to the warfare of his age was not his fortification design, but his novel system of trenches, dug in a zigzag or parallel way so that assailants could reach within range of rampart walls while remaining under cover, and his use of the ricochet fire of mortars to scatter defenders within their own walls. Techniques for driving forward a sap were in themselves a sort of exercise in earthwork construction: trench diggers moved forward, placing baskets filled with earth or rocks (gabions) before them and building up earthen walls along their sides, so that attacking troops could be moved toward the walls, or mines could be laid at the fortification's base. Ingenuity in this regard was considered so valuable that military men sometimes debated whether the shovel was not a more important instrument than the gun.

Management of guns and gunpowder devices was another of the main concerns of the military engineer. Engineers were usually attached to the artillery corps. Their skills in maneuvering machines that weighed anywhere from four hundred to eight thousand pounds were paramount. At the highest levels, engineers were artillery generals, although this rank was usually achieved by noble commanders trained in the engineers' arts and sciences so that, at least, they could command their forces and supervise the engineers under them.

THE SCIENCE OF MILITARY ENGINEERS

Military engineering was transformed into a new profession around the relatively new arts of gunpowder warfare, and many of its practitioners insisted that it was a practice founded on science. By the end of the sixteenth century, an extensive literature on the various practical and intellectual demands of artillery warfare had rolled off the presses. Mathematics and measure were central to the new science of military engineering. In part, this was so because of the mathematical practices traditionally used by architects in their surveying, reconnaissance, and design activities. Military engineers and those who served them were among the most prolific producers of mathematical instruments and practical mathematical knowledge in the early modern period.

Ratio and measure, in fact, appeared to govern most of the new technical tasks, from the recipes for gunpowder (saltpeter, sulfur, and charcoal), to the charge of the cannon (from one-half to two-thirds the weight of the ball), to the measure of range, to proportioning of fortifications. The book knowledge at new academies for the training of cadets, such as the Accademia Delia in Padua, centered around mathematics. Mathematicians began to intervene in the sphere of military engineering as teachers of foundational (and elementary) mathematical skills and as inventors of new mechanical and ballistic knowledge.

Nicolò Tartaglia (1500–1557) was the first mathematician to seek to regularize the unpredictable art of gunnery through mathematics. Galileo Galilei (1546–1642), a student and a sometime teacher of military engineers, also tackled questions that originated in gunnery, even if his solutions were universalized and reframed to address phenomena far outside it. Galileo's "geometrical and military compass" was inspired by the "problem of caliber" (by which one could figure out the proper ratios among weight of gunpowder charge, weight of ball, and bore size), but it could carry out a great number of computational tasks. His years-long study of projectile motion and materials strength culminated in the publication of his last work, Discourses on Two New Sciences (1638), and contained his breakthrough formulations of kinematic motion. Ironically, the mathematical study of projectiles had yielded the philosophical marvel of a terrestrial physics compatible with Copernicanism, but, as Galileo recognized, it was not a useful guide to cannon shot since tables based on his work could not account for air resistance and other technical factors. One of Galileo's disciples, Evangelista Torricelli (1608–1647), did produce tables and instruments for mortar fire. Theoretically derived values are relatively accurate for these short-barreled, upward-shooting artillery pieces.

The problems of air resistance were taken up by Isaac Newton (1642–1727). Using Newton's work, Benjamin Robins (1707–1751) thoroughly investigated musket fire, both theoretically and experimentally. Robins's ballistic pendulum allowed him to demonstrate the dramatic effect of air resistance on the trajectory of a musket bullet and show that muzzle velocity is the most important parameter of artillery performance. However, although his work was translated by Leonard Euler (1707–1783) into German, with commentary, and into French, even engineers who knew Robins's work continued to use range as the significant parameter for another generation.

INSTITUTIONALIZATION AND REFORM

In the eighteenth century, technical schools were established for the development of national corps of military engineers. The French led, with formal engineering schools established by the artillery in 1720. These schools offered both practical and theoretical training, the latter again fashioned around a curriculum of mathematics. Graduates from the engineering schools in France became some of the country's leading scientists and political (or, at least, bureaucratic) leaders.

Meanwhile, European warfare began to move away from ponderous siegecraft. Armies had grown larger and more disciplined, and open battle, including more extensive use of field cannon, increased the mobility of warfare. While lighter field cannons had been experimented with since the sixteenth century, the effectiveness of light cannon in battle was dramatically demonstrated through the success of the Prussian army under Frederick II the Great (ruled 1740–1786). Following the successes of Frederick against the Habsburgs, Prince Joseph Wenzel of Liechtenstein (1696–1772) commissioned a mathematics professor and captain in his artillery corps to redesign a system of guns that included cannons with shorter barrels and thinner walls on redesigned carriages. After the humiliating defeat of the French in the Seven Years' War (1756–1763), they looked to the experience of one of their engineers who had been in Austrian service, Jean Baptiste Vaquette de Gribeauval (1715–1789).

Gribeauval, eventually to become the first inspector-general of the artillery, instituted a number of reforms against the traditions of a much more developed system of military organization, artisanal production, and technical training than existed anywhere else in Europe. In the 1760s Gribeauval advocated similar technological reforms to those adopted in Austria. He also tried to establish the manufacture of gunlocks made with interchangeable parts and oversaw a revamping of the technical schools. The curriculum in engineering schools would teach algebraic analysis, Newtonian science, and the descriptive geometry of technical drawing. The values and mathematical emphasis of this education was foundational to the later establishment of the high écoles, models of technical education from the start and a source of French leaders to this day.

See also Architecture ; Charles VIII (France) ; Firearms ; Frederick II (Prussia) ; Galileo Galilei ; Leonardo da Vinci ; Mathematics ; Michelangelo Buonarroti ; Military ; Seven Years' War (1756–1763) ; Technology .

BIBLIOGRAPHY

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Hall, Bert S. Weapons and Warfare in Renaissance Europe. Baltimore, 1997.

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MacLennan, Ken. "Liechtenstein and Gribauval: 'Artillery Revolution' in Political and Cultural Context." War in History 10, no. 3 (2003): 249–264.

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Steele, Brett D. "Muskets and Pendulums: Benjamin Robins, Leonard Euler, and the Ballistics Revolution." Technology and Culture 35 (1994): 348–382.

Mary Henninger-Voss