INTRODUCTION

WOLFGANG LEFEVRE

The engineers and architects of the Renaissance are renowned not only for the universality of their genius and the audacity of their creations but also for their drawings. Leonardo da Vinci’s famous drawings of technical devices, although unparalleled in many respects, are just one instance of a practice of drawing in the realm of early modern engineering that came into being at the end of the Middle Ages and eventually addressed a broad audience through the Theatres of Machines in the last third of the sixteenth century. The new types and methods of graphic representation developed and used by Renaissance engineers have long attracted the attention of historians of art, architecture, science, and technology. Apart from their often fascinating aesthetic qualities, these drawings have been particularly appreciated as historical documents that testify to the development of technology, the spread of perspective, the psychological roots of technological creativity, and the beginnings of modern scientific attitudes.

As an unintentional consequence of this appreciation, however, little attention has focused on the significance that these drawings had, not for present historians, psychologists, and philosophers, but for the historical actors themselves, that is, for the mechanicians, engineers, and architects of the age. Why did they produce drawings? For whom and for what purposes? What were the prerequisites for this drawing practice, what were the contexts, and what were the consequences? In short, how did drawing shape the practice and the notions of early modern engineers? Those were the questions from which the idea of this volume arose.

Among the many shared views of this volume’s authors (who also differ with respect to several aspects of its topic), there is the conviction that these questions can be successfully approached only by studies that dispense with large generalizations as regards the cultural, technological, intellectual, and aesthetical significance of early modern engineering drawings—generalizations that hampered rather than promoted an adequate recognition of them in the past. They believe firmly that what is needed instead is studies that actually go into the specific details and properties of these drawings—studies that, in addition, focus thoroughly on different aspects of such properties, regardless of whether or not the pursuit of these different aspects leads to a new large synthesis.

The authors’ emphasis thus lay on analysis, fine-grained studies, and close attention to details, and all of them refrained from premature synthesis. The extent to which their studies nevertheless form a connected and consistent whole was surprising even for them. However, the authors being experts in this field of historical investigation, the chapters’ connectedness and coherence may be more obvious to them than to a broader readership. This introduction therefore cannot dispense with giving some indications of the context for these studies. The following outline of the histori-

Cal setting of these drawings as well as of their crucial aspects constitutes neither shared starting points nor jointly achieved results of the authors, but the attempt of the editor to provide a sketchy topography in which each chapter’s choice of issues and perspectives can be located.

TECHNICAL DRAWINGS: SYMPTOM AND INTEGRAL PART OF THE TECHNOLOGICAL TRANSFORMATIONS IN THE EARLY MODERN AGE

In the culture of the West, technical drawings, that is, drawings traced by technicians for professional purposes or those derived from them, appeared only at the end of the Middle Ages and flourished for the first time during the Renaissance. The emergence and development of such a drawing practice is in itself a remarkable fact that indicates profound changes in the social labor process of the West during this age. Traditional production did not employ technical drawings. This holds for agriculture, then and for a long time to come the most important domain of social labor in terms of both the amount of people employed and the wealth produced. For farming, breeding, and growing according to the standards given at the time, and even for manufacturing intricate tools like ploughs, no technical drawings were needed. Surveying, which may come to mind in this context, was not yet a normal part of the agricultural practice. As regards the realm of ordinary crafts, the second important domain of social labor, one encounters by and large the same picture. Almost all of the crafts performed their professional tasks without drawings. An important exception was, naturally, the decorative arts, which passed on established figurative and ornamental patterns through exempla, that is, pattern books (MusterbUcher). But among the drawings of these exempla, only a few could properly be called technical drawings. It was not developments within these established fields of production to which technical drawings owed their birth. Rather, they owed their emergence and development to new sectors of production that transgressed the limits of the traditional labor processes still prevailing, in terms of both the depth of division of labor and the technical procedures applied. And the employment of such drawings is indicative of just these transgressions.

Technical drawings appeared first at the construction sites of Gothic cathedrals. The oldest extant architectural plans date from the thirteenth century. Warfare was the next sector where technical drawings were utilized. Beginning with a few instances in the second half of the fourteenth century and blooming in the fifteenth, drawings of all sorts of assault devices, and increasingly of guns and gun-mountings, heralded the era of early modern machine drawings. Since the middle of the fifteenth century, they were complemented and gradually even outnumbered by drawings of civil devices such as mills of all kinds, cranes and other hoisting devices, and different kinds of pumps and further water-lifting machines for mining and irrigation. Along with this, though apparently following somewhat secluded paths, technical drawings of ships testify to a developmental stage of the ship-building craft where traditional crafts methods, though still indispensable, no longer sufficed.

The emergence and spread of technical drawings thus was part and parcel of new developments in certain exceptional fields in the realm of production that could be called the high-tech sectors of the age. Moreover, these drawings were connected with those very features of all or some of these fields of advanced production by which they distinguished themselves from the traditional ways of production in agriculture and ordinary crafts. The following five features deserve particular attention in this respect, although not all of them occur in each of the sectors of advanced technology.

First, technical drawings were connected with new forms of division of labor characteristic of some of the new high-tech production sectors—forms that developed first at the construction sites of Gothic cathedrals and later, outside architecture, above all along with shipbuilding and mining on a large scale. In these sectors, the flat hierarchy of the typical craft workshop was replaced by complex structures of cooperation, responsibilities, and command. The chief engineer or architect, himself subordinated to clerical or secular commissioners or boards of commissioners, had to instruct and coordinate masters and subcontractors from different crafts who, for their part, directed their teams. The task of coordination often comprised the harmonization of work carried out at different times and different places. Such intricate forms of cooperation among the different parties involved in a project of advanced technology necessitated not only new forms of communication but also new means of communication. Technical drawings are perhaps the most striking of those new means.

Second, technical drawings were connected with new forms of knowledge propagation brought about by the new production sectors of advanced technology. In these sectors, experience with and knowledge gained through new technologies could not be exchanged and circulated effectively by means of the undeveloped and slow communication mechanisms of the medieval crafts. Rather, for these purposes, too, new means of communication were needed, technical drawings included.

Third, and in close relation to this, technical drawings were connected with new forms of learning and instruction that developed along with the new high-tech production. The traditional form in which craftsmen passed on knowledge and skills to the next generation, that is, the system of apprenticeship and journeymen’s traveling that rests essentially on learning by doing, proved to be insufficient to acquire all of the capabilities required by the advanced technologies. First forms of schooling technical knowledge developed. In fact, the art of producing and reading technical drawings constituted a central part of the curriculum of the first technical schools, as is indicated in the very name of the first of these schools, namely the Accademia del disegno in Florence founded in 1563.

Fourth, technical drawings also were closely related to fundamental changes in the body of practical knowledge induced by the advanced production sectors. This body no longer comprised only the traditional experiences and skills of practitioners, but combined them with elements of knowledge that originated in sciences. The expanding employment of geometrical constructions and theorems in several practical contexts is particularly characteristic of this development. The broad range of competence required by the new technologies is best represented by a social figure who came into being with the new fields of advanced production, namely the engineer, who was in charge not only of designing and planning ambitious projects but also of their actual realization through the coordinated cooperation of different kinds of crafts. For these engineers, experience in several crafts was no less important than competence in design and planning, which, for its part, included learned knowledge as well as drawing capabilities.

Fifth, technical drawings were connected with the establishment of technology as a matter of public interest. Pictorial representations of machines and devices of all sorts were a chief means by which the protagonists of the new advanced production sectors managed to attract the attention of the educated public for technological issues. With this, technology became, for the first time in the culture of the West, appreciated as a valuable sphere of culture. The technological transformations of the early modern period entailed a cultural transformation in which drawings played a significant role.

TECHNICAL DRAWINGS IN EARLY MODERN ENGINEERING

The practical role of technical drawings in early modern fields of advanced production was not fixed once and for all. Naturally, for which tasks technical drawings could be employed depended partly on the needs of the engineering process in its concrete social embedment and partly on the capacity of drawings to meet such needs. However, both those needs and that capacity underwent changes—changes that often were intertwined. By using drawings and, above all, by developing particular pictorial languages, engineers discovered the possibilities given by the medium of drawings and broadened the spectrum of tasks for which drawings proved to be useful. Thus, an investigation of the actual functions of engineering drawings requires attention to many different aspects.

Mediating Parties

The most obvious function of technical drawings was a social one, that is, their function as a means of communication between different individuals or, more to the point, different kinds of individuals. They served as a means of communication between practitioners, either those of equal rank or those in a hierarchical relation; between contracting parties, commissioners, and responsible practitioners, as well as the latter and subcontracting practitioners; and between practitioners and a broader public interested in new technology. Mere contemplation of the different constellations of interacting parties makes immediately obvious that “communication” is much too vague a term to characterize the variety of roles technical drawings played in such interactions. In one case, they may have conveyed proposals; in another, they may have documented an agreement; in yet others, they may have fixed decisions, given instructions, served as a basis for consultations and negotiations, exchanged experiences, imposed and secured control, advertised inventions, services, and projects, taught a community of readers, illustrated arguments, and so on. Each of these different cases of social interaction in which technical drawings are employed comprises not only a specific constellation of differing interests but also a specific constellation of differing experiences, competence, and knowledge. Thus, technical drawings could only function successfully as a means of communication and mediation if they allowed for the different and differently informed views of the parties involved. Drawings that served understanding between practitioners of equal rank jointly engaged in a certain project highlighted, or for that matter omitted, other aspects and details of a technical object than drawings that tried to convey an idea of the object to a commissioner. Each case required a different emphasis on completeness, precision, and neatness, and different distinctness as regards information about, for instance, the function of the device in question or its construction.

Studying technical drawings thus can reveal an entire world of social relations between different groups of individuals in which technological projects were embedded. And, conversely failing to take the concrete mediating role of a certain technical drawing into account may seriously impair the understanding of it. Giving testimony as much to the social form of early modern high-tech production as to the technology employed, the technical drawings of the age must be read with social-historical expertise as well as with technological competence. However, the ways in which the extant drawings were passed on often destroyed their original relations to other materials and thus important hints on which a reconstruction of this social context could have rested. As some of this volume’s chapters show, it often is impossible to determine the original purpose and the circumstances of a technical drawing. In some cases, however, an analysis of the drawing style may prove helpful.

Between Pictures and Plans

The variety of ways in which technical drawings were employed as means of communication in the social world around the most advanced technologies of the age involuntarily draws attention to the astonishingly flexible capability of drawings as a medium. How did this medium succeed in serving so many different communication tasks, each of which had different conditions, demands, and purposes? A partial answer to this question may be found in the fact that, on closer inspection, the medium of drawings proves to comprise a whole of graphic languages—that of pictures, of diagrams, of plans, and so on. From a semiotic perspective, each of these different graphic languages follows particular rules and grammars. Accordingly, each of them demands particular expertise for rendering objects in the framework of its rules and also for reading and understanding such renderings. Architectural plans of some complexity, for instance, are only partly understandable to nonexperts. Obviously, different graphical languages presuppose different knowledge and are therefore involved in the discriminations that govern the social distribution of knowledge in a culture. Furthermore, each of these graphic languages has its specific advantages and disadvantages. The graphic language that rules the construction of orthographic plans, for instance, may be unequaled as regards precise information about angles, distances, proportions, and so on. But it cannot compete with the language of perspective rendering when the purpose is to convey an impression of the object as a solid body situated in a surrounding space. Thus there is not only a social aspect of the employment of a specific graphic language but also a material one, that is, the aspect of the possibilities and limits of rendering characteristic of each of these languages. These differences between the material capacities of the various graphic languages by their very nature suggest which specific language is suitable in a certain case. However, the practitioner must additionally consider which of these languages is best understood by the audience in question. Compromises between these two concerns may be unavoidable, and such compromises are, indeed, a characteristic feature of the technical drawings of this age.

Architects and engineers of the early modern period did not only make use of multiple different graphical languages—and often in a virtuose manner—in a certain sense, they also must be regarded as the inventors of these languages. True, from the literary estate of Classic Antiquity, they inherited some clues to the graphic languages employed by their ancient predecessors; and equally true, they could build on some drawing conventions and geometrical techniques used by medieval architects and technicians. They did not have to start from scratch. Yet, as regards the different projection techniques developed in Antiquity—orthographic projection, perspective, geographic projection—each of them was reinvented rather than rediscovered in the Renaissance, and subsequently further developed and refined in an absolutely autonomous manner. Furthermore, against the background of the spread of perspective rendering in the fine arts, the schematic style characteristic of representing machines in the Middle Ages was replaced by a specific style of rendering machines on a single sheet, which was furthermore supplemented by the elaboration of an arsenal of artificial views such as cutaways, exploded views, and so on.

Surveying the styles and techniques of picturing developed from the modest beginnings in the late Middle Ages up to the famous drawings of Leonardo and to the splendid Theatres of Machines at the end of the sixteenth century, one encounters an admirably rich world of pictorial languages that was engendered along with the advanced technologies of the age. The range of these languages—from sketches, to perspective views from a deliberately chosen fictitious viewpoint, and to thoroughly constructed projections—testifies to the wealth of graphic abilities the community of engineers and architects commanded. At the same time it mirrors the broad spectrum of competences that had become characteristic of this community—ranging from practical skill and artisanal experience to learned knowledge.

Shaping Engineering

Among the many striking features of early modern engineering drawings, there is one that deserves particular attention. In contrast to architecture, scaled orthographic plans—ground plans, elevations, sections—were the exception rather than the rule in the realm of machine engineering. In this realm, pictorial representations in a quasiperspective style prevailed. This finding suggests that, in this age, drawings were not as indispensable a means for designing and manufacturing machines as plans and blueprints are today. In the inceptive stage of the designing process, sketches may have been employed by Renaissance engineers in by and large the same manner as by contemporary engineers—I will come back to this in a moment. But, as far as the extant engineer drawings of the age show, the subsequent manufacturing process was not guided by exact plans as it is today. Even the few known instances of employment of orthographic plans in the manufacturing process suggest that these plans served as a means of orientation rather than as a blueprint. The Renaissance engineers could apparently confine themselves to telling the craftsmen in charge of execution some decisive details and leaving the concrete shaping of the machine parts to them. However, this reliance on craftsmen was not reliance on personal experience and tacit knowledge alone. Rather, they were relying on craftsmen who were well equipped with a rich arsenal of geometrical aids developed over centuries—several drawing instruments, templates of all sorts, practitioners’ techniques of creating nontrivial geometrical shapes and developing one geometric figure from another. If one takes this arsenal of practical geometrical aids into account, the machine drawings of Renaissance engineers may appear less inappropriate for the manufacturing process than at first glance. Taken together with the geometrical means at the construction site, early modern machine drawings become recognizable as means of the real construction process.

The employment of drawings in design processes deserves further attention. In these processes, drawings are not simply visualizations of ideas. Rather they function as material means that shape ideas. Their role is that of models that simultaneously provide a fictitious and a real opportunity to test possible arrangements of machine parts, try out new combinations and alternative shapes of these parts, and so on. As material creations in space, drawings are subjected to the laws of space and thus represent real conditions as regards possible spatial relations of rendered objects. (The famous drawings by M. C. Escher, which seemingly transgress these laws, confirm this impressively.) The advantages of such flat models on paper over solid ones made of wood or clay are obvious. They can be created and changed almost instantly. Presupposing some drawing skill on the part of the engineer, their restraint to two dimensions can be compensated for almost completely. They are incomparably flexible and allow unfettered experimentation. They furthermore allow unparalleled concentration on issues of interest thanks to the possibility of omitting all interfering or distracting parts of the device in question and reducing it to its essentials. However, the limits of these models on paper are obvious as well. Being two-dimensional creations, their representational potency ends when the focus is no longer on shapes of machine parts, their spatial relations, and the kinematic significance of such relations—when physical dimensions come to the fore, encompassing the mass and force of the designed object. Nevertheless, within their limits, drawings became an indispensable means of the design process and in this way shaped the very element of the engineering practice on which its fame as an outstandingly innovative activity essentially rests.

THE VOLUME’S FOCUS AND ARRANGEMENT

As stated above, this volume focuses on the functions and significance technical drawings actually had for the professional practice of early modern engineers and architects. It will not address other interesting aspects such as the aesthetic quality of these drawings, the manifold levels of meanings that these drawings had beyond the context of engineering, their place in the visual culture of the Renaissance, and so on. But, as may be obvious after this short introductory outline, despite this concentration on the engineering context, the subject matter is so rich in aspects, dimensions, and structures that one single book cannot aspire to cover it all. Furthermore, as also stated at the beginning, the authors of this volume do not try to present a synthetic view of early modern engineering drawings in the practical context of engineering. Instead they confine themselves to detailed investigations of such drawings under a variety of viewpoints that pertain to this context. If they nevertheless claim to offer more than just a collection of articles that deal with some aspects of this theme, this confidence rests on the conviction that they have concentrated their efforts on such aspects of the topic that are essential for an adequate understanding of technical drawings as means of early modern engineering. The five parts into which the book is divided represent these aspects.

Without anticipating the short introductions that precede each of these parts, their respective focus can be indicated as follows. Part I, entitled Why Pictures o;f Machines? and containing chapter 1 by Marcus Popplow, is about basic categories for ordering the huge and extraordinarily diverse store of extant technical drawings of the age with respect to their origin, purposes, functions, and contexts, thereby providing a first survey of this material. Part II, with the title Pictorial Languages and Social Characters, which contains chapters 2 and 3 by David McGee and Rainer Leng, respectively, is occupied with the development of the specific style of early modern machine rendering and the question of whether and how this style can be considered a response to the different social functions of these drawings. Part III, Seeing and Knowing, with chapter 4 by Pamela O. Long and chapter 5 by Mary Hen-ninger-Voss, addresses knowledge linked with technical drawings, be it the knowledge presupposed and/or conveyed by them, or knowledge that is presupposed but cannot be conveyed. Part IV, Producing Shapes, with chapters 6 through 8 by Filippo Camerota, Wolfgang Lefevre, and Jeanne Peiffer, respectively, focuses on the development of drawing techniques that required, either from the beginning or in the course of their evolution, familiarity with learned knowledge such as geometry or geometric optics. Part V, finally, Practice Meets Theory, with chapter 9 by Michael S. Mahoney, is dedicated to technical drawings at the interface between practical and theoretical mechanics.

To a certain extent, particularly as regards the fifteenth century, the arrangement of the volume also reflects main stages in the historical development of early modern engineering drawings. After chapter 1, which provides an analytical survey of the technical drawings of this age, chapters 2 and 3 discuss the emergence and the first stage of the specific early modern type of machine rendering in fifteenth-century Italy (Taccola) and Germany (BUchsenmeistertraktate), respectively. Whereas chapter 7 contains an outline of the development of architectural plans up to the first decades of the sixteenth century, chapter 4 presents the mature stage that machine drawings achieved with Giorgio Martini and Leonardo da Vinci in the second half of the fifteenth century, a maturity that was not surpassed by the succeeding development of early modern engineering drawing. This further development is not traced coherently in this volume, with the conspicuous consequence that the famous Theatres of Machines from the last decades of the sixteenth and the beginning of the seventeenth centuries are not discussed as a special issue. This omission resulted mainly from the volume’s focus on the functions and significance technical drawings had in the engineering practice. Although partly deriving from those of immediate practical context, and although constituting in no way a separate or particular genus of engineering drawings, the drawings of the Theatres served the propagation rather than the real practice of engineering. The same holds for the rightly renowned woodcuts in Georgius Agricola’s De re metallica from 1556. The fact that this treatise and those Theatres, the majority of which is accessible through exemplary modern editions, have enjoyed thorough scholarly attention in the last decades made the decision easier to refrain from addressing them in favor of much less investigated issues such as decision making by means of plans (chapter 5), drawing techniques of a learned character (chapters 6 through 8), and the relation between engineering drawings and theoretical mechanics (chapter 9).

ACKNOWLEDGMENTS

The idea of this volume arose after a small conference on engineering drawings of the Renaissance, which was organized by the editor together with David McGee and Marcus Popplow and held at the Max Planck Institute for the History of Science, Berlin, in summer 2001. The authors who eventually joined in this book project circulated drafts of their chapters several times and met in winter 2002, again at the MPI in Berlin, for a thorough discussion of each contribution as well as of the focus and arrangement of the volume as a whole. My first thanks go to them. Seriously engaged in the volume’s topic and cooperating in an unusual spirit of good fellowship, they never failed in promptly and patiently reacting to all of the greater and smaller demands such a book entails. Our joint work was an exciting and rewarding experience!

Warm thanks also go to James Bennett, Raz Chen, Judith V. Field, Bert S. Hall, Volker Hoffmann, Alex G. Keller, Antoinette Roesler-Friedenthal, and Thomas B. Settle, who contributed to the 2001 conference and discussed earlier versions of a number of the volume’s chapters both critically and constructively.

The planning, organization, and realization of such an extensive and costly production process was only possible with the backing of the Max Planck Institute for the History of Science, Berlin. Jurgen Renn, who runs Department I of the institute, where preclassical mechanics constitutes the subject of one of the current long-term projects, provided the requisite support for the enterprise and accompanied it through its course with unceasing sympathy and encouragement. Many thanks!

Furthermore I would like to thank Jed Z. Buchwald for the decision to include the book in his Transformations series. Dealing with a topic that relates to the history of both science and technology, the volume could not have found better company.

Like machines, to actually come into being, books need to be not only designed (written) but also manufactured. My thanks go therefore to Angelika Irmscher, Heinz Reddner, and Susan Richter, who assisted in the editorial work and helped to bring the manuscript with all the figures to its final camera-ready form. Finally, I want to thank Sara Meirowitz, responsible for the science, technology, and society books at the MIT Press, who discreetly and reliably provided every support needed.