5 The Context of the Art of War and the Role of Metallurgy
Tartaglia’s work immediately positioned itself in a market gap of intellectual thought that obviously urgently needed to be filled. If the Nova scientia is considered alone, this work did, in fact, capture the interest of not only mathematicians, but also military officials dedicated to the use of heavy artillery, who were avidly increasing their arsenal of practical applications of mathematical knowledge. Tartaglia’s text thus straddled the boundaries between two types of activity, one intellectual and the other practical, as well as two types of social sectors, i.e. academic and military. In order to fully understand this assertion, however, a deeper understanding of the art of war in Tartaglia’s time is required. In the literature concerning the birth and development of ballistics, it is generally affirmed that the science of ballistics was the natural theoretical development following the diffusion of firearms from the fifteenth century onwards. It is true that the deployment of firearms during sieges became an undeniable reality in the fifteenth century, but analyzing the details of technological development during that century reveals that there was no need for a science of ballistics such as that formulated by Tartaglia.1
Owing to the development of metallurgy, over the course of the fifteenth century specific types of heavy artillery began to be produced, which was used mainly during sieges on fortresses and fortified towns. Right from the beginning, two categories of artillery were produced: one which was able to fire relatively light cannon balls (between 12 and 25 kilograms), and one which was intended to destroy architectural structures of fortifications, and therefore capable of firing cannon balls weighing up to several hundred kilograms. Technological developments in the fifteenth century concentrated primarily on the heaviest artillery. Several reasons account for this development.
Throughout the fifteenth century, the process of fortification, for the most part, was still geared towards remodeling the architecture of the old, medieval-style fortress. Incisions were made in the old defense walls and reinforced with embankments, which were also used to mount defensive artillery. Nonetheless, the fundamental structure was rarely changed or adapted to the new strategies of attack. In fact, the fifteenth century can be characterized as a period in which the advantage clearly lay with strategies for attack rather than with defense. Not until the first half of the sixteenth century was the balance restored, when architecture was finally able to provide a response to the development of metallurgy. It was the development of a new art of fortification, in particular, the development of the bastion as a fundamental element of defense, that succeeded in putting attack and defense onto a more equal footing, at least as far as sieges on fortresses were concerned.2 In 1527 it was Albrecht Dürer3 who declared the end of old fortresses, even if they had been readapted. It was he who expressed an absolute necessity for new fortresses to be built from scratch, following a geometrical plan of construction conceived on the basis of the strategies of attack and defense made possible by the new firearms. Ultimately it was Italian military architecture that developed and perfected a new system of defense. Thus, the new art of fortification was not established until the first half of the sixteenth century, a full century after the first imposing developments in artillery had been made. However, the interim also saw considerable changes in the design, construction, power and use of artillery, and these changes must be considered in order to understand the Nova scientia.
In the fifteenth century, there was a demand for artillery of huge dimensions, as this was the only kind capable of destroying fortified lines. In fact, this form of artillery mainly used large balls made of stone, whose destructive power was exerted upon falling on the target. It was therefore necessary to have cannons capable of launching cannon balls of enormous dimensions as high into the air as possible. On one hand, the large “wall breakers” (Mauerbrecher) built by Teutonic experts, or the typical bombards that were widely used in Italy, launched projectiles at a high angle of elevation. On the other hand, the technology had not yet been developed to keep the artillery sufficiently fixed to the ground, and thus to avoid serious damage from the effects of the cannon’s recoil. From this point of view, the bombard had been particularly well thought out insofar as it practically lay on the ground. Furthermore, the process of loading the barrel of the cannon, the quality of the gunpowder and, above all, the quality of the cannon itself from the metallurgical perspective, made it impossible to fire shots that would follow almost rectilinear trajectories. The crackling generally associated with the flight of a cannon ball, for example, is a phenomenon that was observed only after the beginning of the eighteenth century. The velocity of projectiles fired from fifteenth-century artillery was much slower than is generally thought.
Returning now to the Nova scientia, it is clear that the theory of ballistics developed in that work had no relation whatsoever with the reality of the fifteenth-century bombardier. The latter would have had more use for a theoretical treatment of the last segment of the trajectory, i.e. the part conceived as natural motion.
The principal aim of modern ballistics is to set up a shot in advance in order to hit a target whose position is known. Yet during the fifteenth century, there had been no demand for ballistics from this perspective. Following the arrival of new rules for fortifications in the sixteenth century, above all for bastions, a typical strategy of attack was developed during sieges, which focused primarily on destroying one of the bastions of the fortress. This made it possible to gain an area along the curtain wall where defense became comparatively weaker, and where it was thus possible to move from siege to attack and ultimately occupation. Depending on its type of construction, the bastion could and had to be destroyed following a very precise strategy. For example, first of all, the lower and upper defenses of the bastion itself had to be destroyed.
This meant that entire batteries of cannons had to concentrate their fire on one or a few chosen points whose distance and height had to be calculated with precision. In this context, a science of ballistics was doubtlessly necessary and welcome (Fig. 5.1).
The situation had been quite different in the fifteenth century. Strategies focused on destroying as much as possible of the inside of the fortress. A precise shot was not fundamentally important, and the experience of the bombardier was more than sufficient to achieve the objectives.
In order to understand the context of the birth of ballistics, another important technological innovation must be considered, as well as its consequences. A new, much smaller type of projectile began to come into use from the end of the fifteenth century (more specifically from the time of the first of the Italian Wars), produced by melting the iron in such a way as to obtain cast iron, albeit not really comparable with present-day cast iron. Due to developments in metallurgy and to innovations that increased the efficiency of hydraulic apparatuses applied to run ventilation systems at the end of the fifteenth century, furnaces were produced that were capable of reaching much higher temperatures than ever before. A new kind of cannon ball began to be produced in these smaller furnaces, while cannons continued to be produced using wrought iron or, later, cast bronze.
Fig. 5.1: Drawing illustrating how, during the sixteenth century, artillery was used by targeting points in the front of the fortress whose distance was measured by means of a straight line. These replaced the buildings located inside the fortress as targets to be destroyed by means of high shots over the walls. From the German edition of Ramelli 1588 published in 1620.
This innovation resulted in a veritable revolution. Cast iron cannon balls of a relatively low caliber revealed a much higher capacity for penetration and destruction than those made of stone. The latter, if low in caliber, disintegrated and crumbled on impact with the target and, as has been mentioned, only had a potential for destruction if they were of very large dimensions and in free fall. The low caliber of the cast-iron cannon balls finally allowed for the possibility of using smaller and therefore lighter artillery that was easier to transport and cheaper to produce. It was this innovation that led to a significant increase in the velocity of projectiles, and which established heavy artillery once and for all as essential to the art of war, such that it spread to a hitherto unimaginable extent.
Over the following decades, the caliber and type of artillery were geared towards the setting of standards, each of which was valid within at least one single political entity. There was a change in the institutional role of the artillerymen, who until then had also often been the metal founders who accompanied soldiers during military campaigns. On the one hand, new foundries were established; and on the other, the figure of the bombardier became institutionalized in the military ranks. From there, the creation of special artillery schools where new soldiers could be trained was just a short step away. At this point, the perfect institutional vessel had been created for the newly emerging science of ballistics.
One of the best works explaining the developments of the art of war in the fifteenth century is still the fourth volume of Delbrück 2000, published for the first time in 1920. For a more in-depth treatment of the subject of the development of artillery, see in particular Egg et.al. 1971, Schmidtchen 1977 and Hall 1997.