The use of computerized graphics in the history of technologies
Computer graphics applications are powerful teaching and communications tools which we would find it hard to do without nowadays. In the history of technology, digital design plays an important part in the study of the machines and mechanical structures to be found in the manuscripts written by engineers of the past. The ability to produce strictly accurate designs of animated three-dimensional models within a “virtual space”, i.e. the computer monitor, is an indispensable visual aid that is of assistance at the analytical stage, when the historian’s efforts are concentrated on understanding the elements that make up the machine, and also at the stage of reconstruction when, with all the parts and dimensions identified, he attempts to assemble them to check whether or not they would work in practice.
Design is the main “language” of technology and an academic who wishes to study the history of the subject must know how this language evolved from ancient times up to the present day. Just as a document with socio-political or scientific value is translated from an ancient language into a modern one, a historian who studies technology translates technological figures drawn in accordance with rules of design that are now out of date into a modern graphic “grammar”. In this way, we can understand the historical images we can no longer decode at first sight because our eyes are now so accustomed to realistic representations of perspective.
Reconstructing a machine, even if only in the form of a virtual model, poses a number of problems, such as the dimensions and kinematics scanning of its moving parts, which lead us to speculate about the choices made by the original builder and evaluate the good points and the limitations of the technology he adopted. The operation is far from simple, and we risk jumping to conclusions or misunderstandings because we project our modern technological mentality onto the past; our modern outlook prevents us from viewing the machine with the background knowledge and customs current at the time when it was built.
No matter how explicit they may be, the drawings and descriptions of the machines contained in the manuscripts of medieval and Renaissance engineers were not considered “plans” in the modern sense of the term. The idea of a “plan”, that is the depiction, calculation and classification of all the parts and technical procedures necessary for the construction of a machine, cannot be applied to the Renaissance period.
Despite the fact that quantitative graphic tools such as scale modeling and dimensioning have been in use since the second half of the 16th century, technical drawing was then judged in the same way as art; the machine was seen as an artistic object which, thanks to the rigors of geometry and the rules of perspective, could be adequately portrayed; but the question of conveying information on how the machine worked had no place in the purpose of these drawings. Even if a great number of graphic devices were prescribed to achieve a clear picture that would bring out the particular technical qualities of the machine – views in plan and in elevation, drawings that revealed internal components, sectional or exploded views, simulations of kinematic sequences, shading to identify surfaces in contact with one another, schematic drawings of the lines of force, etc. – drawings of machines, even those by Leonardo, essentially pursued two ends: one with a kind of symbolic and ideological nature intended to establish the inventor’s place in society and promote his accomplishments in his search for a noble patron, and the other with a more theoretical purpose, that is, as a visual aid to the production and development of a technological idea.
When the time came to convert the information needed to build the machine from theory into practice, these details were not taken directly from the plans, but were first of all turned into a wooden scale model, which was used to check the feasibility of various approaches that, until then, had only been ideas on paper. Although drafted meticulously, these drawings could only be reflection of the actual machine and it was the workman’s job to interpret them with the aid of his own acquired technical knowledge and his own experience, in order to arrive at a machine that worked. That is why, today, it is impossible to bridge the gulf between the drawings made by the Renaissance engineers and the actual machines they represent.
We must always remember these limitations when we examine or build a virtual model of a machine of the pre-technological age (before the first Industrial Revolution). However, even if the Renaissance engineers’ drawings of machines were intended to remain on paper, a historian who has taken their inherent limitations into account must then try to see beyond the “portraits” of the machines found in the manuscripts in order to seek an understanding of how they really were in the past. From this point of view, if the virtual models are created in accordance with strict philological criteria integrating pictorial sources (drawings and prints) with written information (annotations about materials used, dimensions, impressions of how things worked) and actual materials (from archaeological finds), we believe that the gap between the drawing and the real, working machine can be to a great extent decreased. Although we recognize that there is an element of imagination in our reconstructions, it is possible to attempt a quantitative study of these machines that perceives the virtual models as both a means and a target of research.
Another relevant use of computer graphics is found in the so-called “technological fantasies”, that is to say, impossible machines such as those that move by means of perpetual motion or Leonardo’s flying machine. Applied in this way, “virtual reality” enables us to “bring to life” or “animate” kinematics ideas and constructions that until now have existed solely in the imagination or, at best, as static wooden models. This is especially true in the case of Leonardo da Vinci who, more than any other engineer, expounded his technological fantasies in the form of the splendid plans and drawings that have come down to us, which we can use to recreate the way his ideas developed and perceive his most daring hypotheses.
This is how the use of computer graphics in studying the history of technology has two parts to play: on the one hand, it is a powerful analytical instrument to assist and guide our understanding of the machines and on the other, it is a “translation tool” that enables the historian to communicate the results of his own researches in the language of images, a modern language that is easily comprehensible even to those who lack specialist knowledge.
Thanks to computer animation and photographic rendering, it is possible to create realistic video sequences that transport us into a “virtual historic environment” in which the machines or technical processes are presented in a realistic graphic format that allows the modern user to enter into contact with the ideas, materials and technical problems that were a feature of technology in the past. In conclusion, it is our duty to remember that the use of multimedia resources in popularizing technology is legitimate only when based on the original documents, to which the virtual model must always remain faithful; and such use is justified, always with reference to original sources, by the reasons that prompt us to develop some ideas rather than others.