Introduction

The database DMD is part of the research project The Relation of Practical Experience and Conceptual Structures in the Emergence of Science: Mental Models in the History of Mechanics, a project pursued by Department I of the Max Planck Institute for the History of Science (MPIWG), Berlin, headed by Jürgen Renn. In its context, a large number of original sources concerning the history of mechanics have been made available on the Internet as a digital research library, the Archimedes Project. In this broader context the database DMD is especially devoted to studying the practical knowledge of early modern engineers.

The aim of the database DMD is the provision of new ways of investigating early modern machine drawings. These documents are important not only for historians of technology but also for historians of science and art and more generally for scholars of Renaissance studies. DMD provides these opportunities in a twofold way: first, it provides convenient access to a representative selection of early modern machine drawings and, second, it presents each drawing in a frame of categories, which allow the selection to be searched under a broad spectrum of questions and viewpoints.

With respect to time, our selection includes machine drawings from the late Middle Ages up to 1650, that is, from the earliest picture manuscripts of engineering drawings to the end of the first boom of Theatres of Machines. With respect to the definition of machine drawings underlying our selection, we confined the selection to those machine drawings that were traced by engineers (or by their order) and that were actually used by them in pursuit of their professional aims. Furthermore, drawings that can be derived from those engineering drawings are also included.

There are two basic requisites for electronic databases. First, they require categorization: The fields of a database’s record constitute categories or aspects into which information on the item in question can be distributed. Second, they require searchable signs: Only letters and numbers are admitted in a field. Thus there are two main challenges for an image database. First, the challenge of categorizing information: There is no established categorization of aspects of engineering drawings. This kind of categorization must first be developed. Second, the challenge of verbalizing pictorial information: There is neither an established verbalization of pictorial elements in general, nor an established terminology for technical devices and their parts. As to categorizing, besides fields for the most general information, DMD has three main groups of special categories. The first group concerns the question: Where does the drawing originate from? This group contains categories of a drawing’s bibliographical whereabouts. The second group concerns the question: What is depicted? This group contains categories of the depicted object’s technological whereabouts. The third group concerns the issue of a drawing’s pictorial language and social context. This group contains categories of a drawing’s semiotic and sociological aspects.

The main view of a record provides general information on the respective drawing. By clicking on the image, the drawing can be enlarged and submitted to a number of operations.By clicking on the text fragment below the picture, a new window with the complete text pertaining to the drawing — transcription and translation — pops up. Besides the activated tab entitled “Overview,” one finds three more tabs: “Source,” “Device,” and “Image,” which lead to a record’s supplementary views comprising the three special groups of categories mentioned above.

The supplementary view “Source,” contains the usual bibliographical categories. A database with the literature used is linked to the entries in the field “Secondary literature.”

The supplementary view “Device,” provides technological categories for capturing the depicted device. First, categories that allow the device at hand to be placed in broader technological contexts—which type of machine it represents, where it is employed, and how it is powered. Second, fields in which the depicted parts of the device are listed. Third, a field where gearing combinations are listed, if there are any available.

Successfully searching these fields requires that all entries follow a standardized terminology. Here we encounter the problem of verbalization. Of the many serious terminological problems that occurred in the course of this verbalization, two may be addressed explicitly. First, the technological terminology used may not be familiar to many of the database’s users. Therefore, a pictorial glossary is provided and linked to the entries in the fields for machine parts and gearing combinations. The second problem is anachronism. We decided to use the language of modern-day engineers. This is certainly a problematic decision. However, we didn’t see any reasonable alternative to this. As to the historical actors’ terminology, it can be traced to some extent in the texts pertaining to the drawings.

For reconstructing the multi-dimensional meaning and context of engineering drawings, their actual or intended use is key. However, since it is often impossible to determine this use, further clues to meaning and context must be considered. The supplementary view “Image” provides a further group of categories that attempt to capture information pointing either directly or indirectly to such clues.

Directly: Information on the provenance of a drawing, its presumable addressee, and its presumable purpose. The establishment of the use of an early modern engineering drawing is of highest significance for a competent and comprehensive understanding. Engineering drawings represent much more than just a particular technical device. As a means of communicating, contracting, controlling, instructing, illustrating, etc., they represent the social relations between the different players as well as a subtle interplay between different experiences, kinds and levels of knowledge, and different expectations on the part of the engineer and of his addressee. In many cases, due to lack of information, we had to enter a laconic “unknown” in these fields. The cases for which an entry has been made should be considered as a challengeable assumption.

Indirectly: Information on the pictorial language chosen and, furthermore, narrative elements of the drawing, if present. The pictorial language in particular can give clues to the possible use of he drawing at hand. A sketch made for private purposes, for instance, usually employs other graphic techniques than a drawing that instructs a craftsman in charge of construction. This work drawing, in turn, will probably differ from a drawing made for a commissioner or for the broad public.

Regarding the description of the images’ “physical qualities,” we distinguished so far only very roughly between “drawing,” “woodcut,” and “engraving.” In the near future, we will add further categories that will do more justice to the broad variety of graphic techniques. Furthermore, information on the original size of the sheets displayed will be added.

DMD will be brought online successively in several steps. Its first issue comprises roughly 1850 drawings. However, it does not include any drawings by Leonardo da Vinci. A selection of his machine drawings will follow in a later issue, machine drawings of other early modern engineers will be consecutively added to the database as well.

This is just a short introduction of the main features of DMD. For questions, suggestions, corrections, and so on, please use the e-mail address under “Contact.” If you would like to be informed of the substantial updates of DMD, please let us know.

Berlin, September 2006
Wolfgang Lefèvre   Marcus Popplow