Giovanni de’Dondi and Guido da Vigevano: Notes Toward a Typology of Medieval Technological Writings B E R T S . HALL zyxw Institute for the History and Philosophy of Science and Technology Center for Medieval Studies University of Toronto Toronto, Canada M5SiAi I now some 40 years since the study of technology in medieval Europe emerged as a serious scholarly occupation, and during that time we have learned a great deal about the importance of technology in the changing patterns of medieval life.’ Along the way we have uncovered a substantial amount of information about both general patterns of technological development in the period and also about the documentary remains that reflect -with greater or lesser degrees of accuracy-the knowledge of medieval people about matters technical. Many desiderata remain to be fulfilled in this enterprise at present, among them a satisfactory scheme of categories within which various documents can be placed for further study, i.e. a typology of medieval technological writings. Unfortunately, the field is rather untidy and a great deal of work will have to be done before a full framework can be created. I would like to make a preliminary contribution to this task, however, by trying to distinguish two major types of technological writing in the middle ages. In keeping with the theme of this conference, two works written during Machaut’s lifetime have been selected to serve as model examples of their types: Giovanni de’Dondi’s Tractatus astrarii and Guido da Vigevano’s Texaurus Regis Francie acquisicionis Terre Sancte de ultra mare. This paper describes both works, makes some remarks about their authors, and seeks to place each within a tradition of similar writings. Naturally, we cannot expect such a procedure to give us a comprehensive view of technological writings during the midT is zy zyxwvut [1281 NEW YORK ACADEMY OF SCIENCES dle ages, but for purposes of a preliminary categorization, two examples will suffice. SCHOLARS AND CRAFTSMEN Early in his career, the student of medieval technology must confront the slightly embarrassing fact that medieval people left remarkably few didactic writings on technology, despite their considerable range of technological accomplishments. We have become aware of these accomplishments largely by relying on sources that accidentally give us information about technology : casual references in chronicles; works of literature or philosophy; artistic representations showing tools or machines in common use; or the surviving artifacts themselves, which can yield a rich harvest of information when properly analyzed. None of these was consciously intended to give the user or reader much insight into technology as such, and the historian must engage in a substantial effort of reconstruction when he uses them as sources. Technological treatises with self-conscious didactic intent are rare in the middle ages, or for that matter in cIassical antiquity. To the modern mind, this combination of technical achievement and extreme reticence is most difficult to understand, It is usually accounted for by some variation on the theme of scholars and craftsmen2 Scholar-craftsman arguments take as their starting point a number of gaps between the mental world of the learned and that of the skilled manual worker. Craftsmen are, for most of the period under discussion, illiterate, and thus unlikely to compose great tomes on their arts. Craftsmen learn their skills as apprentices, in their masters’ workshops, by word-ofmouth and by example. They have little or no need for written material to instruct them or assist them in their daily work. Scholars, on the other hand are equally the prisoners of their educations, which were generally rhetorical, not practical, and through which they absorbed attitudes of disdain for the world of physical work. Even if they could have overcome their biases, the argument continues, it is questionable whether they were equipped by their educations to make intelligent comments on the messy and complex operations that the craftsmen performed. The purpose of philosophy was to understand the cosmos, not to bake bread or make pots. Stated in this way, the argument is, of course, a caricature of the attitudes and abilities of both scholars and craftsmen, but the general line of argument has some merit nevertheless. We do have but a few treatises on technology, and fewer still can be shown to be from the pens of craftsmen. We do have examples of technological comments that reveal the ignorance zyxwvut zyxwvutsrq HALL : GIOVANNI DE’DONDI AND GUIDO DA VIGEVANO [1291 of the commentator, and other examples of text which have become deeply corrupted because the scribes who copied them knew nothing of the subjects they d i s c ~ s s e d .Whatever ~ misgivings one may have about the scholar-craftsman argument, it must, I think, be accepted as a general description of conditions and limits that shaped medieval technological writings. The problem is to modify the argument so that it can incorporate the documents we do have, and as we shall see, the fourteenth-century works allow us to do just that. G I O V A N N I DE‘DONDI Let us look first at the work of Giovanni de’Dondi (1318-1389).~He was a physician and the son of a physician, Jacopo de’Dondi; he taught medicine at the University of Padua from 1350 or 1352 and later at the Uni.versity of Pavia. He played minor roles in the political life of his day and was rather famous for his learning. From 1348 to 1364 he built in his spare time and apparently with his own hands a very complex astronomical clock which became one of the marvels of his age (FIGUREI). At any rate, we would call Giovanni’s creation a clock, but he used the word “astrarium” to describe it. (The closest analogy in modem English would be ”planetarium.”) By means of seven large dials it displayed the motions of the sun and the moon as well as those of the five planets then known; in addition the machine had a 24-hour dial, indications of the dates of the fixed and moveable feasts, the nodes (points of intersection of the solar and lunar orbits), and the times of sunrise and sunset in Padua. The complex gearing necessary to achieve these motions was driven by a vergeand-balance wheel escapement powered by a hanging weight. Made of brass and bronze, the completed instrument contained 297 parts, stood 5 2 inches (1.32 m) high and was about 30 inches (76 cm) in diameter. The astrariuin survived until 1529 or 1530, after which all traces of it disappear from the historical record. Modern reconstructions may be seen at the Smithsonian Institution in Washington, D.C. and at the Museo NazionaIe della Scienze e della Tecnica in Milan. The reason we have been able to make reconstructions in this century of a machine that disappeared more than 400 years ago is that Giovanni left behind a detailed descriptive treatise on his work, Tractatus asfrarii, also known in some copies as Opus planetarium; the text survives in xi manuscripts, only one of which can be shown to date from Giovanni‘s lifetime. Giovanni describes his motives for wanting to build such a device in the preface: his wish to bring some measure of common appreciation to zy zy zy zy NEW YORK ACADEMY OF SCIENCES zyxwvutsrq zyxwvutsrq FIGURE 1. Model of the astrarium of Giovanni de’Dondi, showing several dials plus the hour indicator, gearing and weight drive. With permission of the Smithsonian Institution, Washington, D.C. zyxwvutsrq HALL : GIOVANNI DE’DONDI AND GUIDO DA VIGEVANO [1311 zyxwvuts zyx zyxw the noble, but difficult, art of astronomy and his wish to demonstrate a correct, i.e. pristine and unmodified, Aristotelian-Ptolemaic version of theories of planetary motion. He relates his initial inspiration to his reading of the Theorica planetarum of Campanus of Novara, a work of the thirteenth century, and Campanus’s description of an equatorium. (The equatorium was an unmotorized computational instrument roughly comparable to the astrolabe for solving problems in planetary astronomy; Theorica planetarum was one of the most significant Latin works on the subject.) The rest of the Tractatus is devoted to detailed descriptions of constructional matters relating to the astrarium itself, concentrating on gear trains, their calculation and arrangement. The work is illustrated by numerous diagrams, again mainly of gear trains (FIGURE2). These are difficult to interpret by themselves without recourse to the text; clearly they were meant to assist a reader to understand some of the difficult points of construction. Both Giovanni’s machine and the treatise in which he describes it can be related to a very old tradition of complex geared devices and writings about them. Indeed, before about A.D. 1400 instrument treatises make up the single most numerous category of technical treatises. We have vague accounts of elaborate planetaria that Archimedes is supposed to have constructed, and there is physical evidence in the form of the so-called “Antikythera Machine” that somewhat simpler geared astronomical computation machines were in fact built in the first century B . c . ~Though we have no written tradition that describes anything so complex as the ”Antikythera Machines,“ we do have a body of descriptive treatises under the names of Philon of Byzantium (fl. late third century B.c.) and Heron of Alexandra (first century of our era) on such topics as surveying instruments, clepsydrae (water clocks), pneumatic devices (mainly toys), automata, and catapults. Significantly, both Philon and Heron are associated with the famous ”Museum of Alexandra,” that unique ”research institute” of antiquity. Neither the tradition of writing such treatises nor the skills to make sophisticated instruments survived in Europe past the collapse of Roman power, but both are visible in Islam from at least the eighth century onwards. We know of elaborate water-clocks with associated automata, we find both Heron and Philon in Arabic versions at an early date, and we have a line of indigenous Arabic treatises stretching from the Banii MusB in the ninth century to al-Jazari and Ridwan in the early thirteenth.s The tradition reappears in the West in the eleventh century with translations from Arabic works on astronomical instruments, and there- NEW YORK ACADEMY OF SCIENCES zyxwvuts zyxwvutsrq FIGURE2.Schematic drawing of the astrarium’s movement from the oldest extant manuscript, Cod. D. 39 of the Biblioteca Capitolare Vescovile, Padua. With permission. zyxwv zyxw HALL:GIOVANNI DE’DONDI AND GUIDO DA VIGEVANO [I331 after we find a fairly continuous development of such works. The name of Richard of Wallingford, whose Tractatus horologii astronomici (c. 1330) gives us the earliest extant description of a weight-driven clock, should be mentioned; the paper by J. D. North later in this volume provides some additional detail.7 There is ,therefore, a solid and reasonably continuous tradition of clockwork instruments and descriptive treatises running back from Giovanni de’Dondi to before the time of Christ. Making some allowances for individual variations and modes of expression, these instrument treatises share many common characteristics. They all seem to have been written by men who had practical experience with the devices they discuss; there does not seem to be a dilettante in the lot. They are all intensely descriptive, heavily oriented toward the exposition of details of design and construction. Their ostensible purpose is to permit a reader to build the machine in question, but they almost always leave the impression that the reader had better know something in advance about the subject under discussion, for they make no concessions to his possible ignorance of major matters. Giovanni, for example, explicitly makes this point when he glosses over the all-important matter of the escapement mechanism, noting only that his is like that in common use. He further advises anyone who does not understand such simple matters not to press on to the greater difficulties that lie ahead. Since we are in fact greatly interested in the early development of escapements, we find Giovanni’s attitude lamentable; alas, Richard of Wallingford seems hardly more informative about the escapement of his horologiurn. The presumptive conclusion from such episodes as these is that we are dealing with a literature by specialists and for specialists. Something similar is manifest in the treatment accorded illustrations in these works. We rarely get a picture of what a machine actually looked like; we have only diagrams of the details, and these serve almost exclusively to elucidate difficult aspects of the text. Again, the specialist would know what the overall machine should look like, but he might need visual help with difficult details. Finally, and again with individual exceptions, the instrument treatises are in one respect rather unimaginative. That is to say, the locus of imagination, of creativity, is in the machines and their design, not in the texts that describe them. There are no leaps of thought, no sense of trial-and-error, no attempts to describe possible variations on the established theme. The preferred style is flat, somewhat laconic, almost disembodied, and purely descriptive. Now these qualities may seem entirely admirable in a technological [I341 zyxwvut zyx zyx NEW YORK ACADEMY OF SCIENCES work, and indeed, they are, but they are not the only qualities such writings can show, as we shall see when we consider Guido da Vigevano. First, however, let us glance backwards at the scholar-craftsman argument mentioned earlier. What does the existence of a well-established tradition of instrument treatises mean for the general thesis? It would seem that in the specialized business of designing and describing complex instruments, the gap between scholars and craftsmen was narrower than elsewhere in technology. Obviously the ability to read and work with numbers was a sine qua non of complex instrument design and construction. Hence a craftsman working with such devices is more likely to have been literate enough to compose a treatise, as for example al-Jazari was. Scholars, on the other hand, would seem to have been on safe grounds in showing an interest in the science of astronomy and devices closely related to it. Recall that both Giovanni and his father Jacopo were physicians and thus professionally related to astronomers and astrologers. The relentlessly descriptive and uncompromising quality of most such texts suggests that the authors thought to address only like-minded men; there is no question of reaching for the untutored. The intellectual labor of designing complex instruments, and especially the mathematical demands of such activity, made it into a type of High Technology (to borrow Derek Price's term from another context) which was more attractive to scholars than the ruder business of mills, or mines, or siegecraft. Lastly, and almost paradoxically, though such instruments were extraordinarily complex and demanding, they were within the intellectual grasp of men properly trained in (let us say) Ptolemaic astronomy in a way that the still greater subtlety of, for example, metallurgical chemistry or the fluid dynamics of water-wheels could never have been. In other words, instrument design fitted within the compass of ancient and medieval natural philosophy in a way that no other branch of technology did. For all these reasons we may accept the manifest existence of the tradition of instrument treatises without discarding the scholar-craftsman argument. zy GUIDO D A VIGEVANO Let us turn now to Guido da Vigevano,' who, like Giovanni de'Dondi, was a physician. His career had taken him to France where in the 1330s he found himself court physician to Jeanne of Burgundy, Queen to Philip VI, the first of the Valois line. The new king had twice pledged himself to the reconquest of the Holy Land, vows which we know were empty HALL:GIOVANNI DE'DONDI AND GUIDO DA VIGEVANO zyxw 11351 zy gestures, but which were taken with great seriousness at the French court, at least for a time. Guido seized on the opportunity presented by the crusading fervor to present in ca. 1335 a treatise to his monarch on new and better means for combating the infidel. He called it "Treasury of the King of France for the recovery of the Holy Land beyond the sea, and of the health of his body, and of the prolongation of his life, together with a safeguard against poisons." True to his calling, Guido devoted the first half of his work to medical advice about protecting one's health while in zyxwvutsrqp FIGURE3 . Guido da Vigevano's paddle-wheel boat with crankshaft drive. The paddlewheels are indicated by the cross-shaped extensions at each end of the crankshafts. With permission of the Bibliothkque Nationale, Paris. W I zyxwvuts NEW YORK ACADEMY OF SCIENCES the field. More than mere professional pride may have been a t work here, for disease had been at least as effective as Muslim arms in stopping earlier crusades. Moreover, deliberate poisoning of the politically powerful was somewhat more common in the fourteenth century than is customary in polite society today, and Guido‘s own remedy against aconite poisoning, which involved a soup made of slugs that fed on aconite leaves, was a matter of special pride to the physician.9 In the latter half of his manuscript Guido devotes his attention to siege engines with which to assault the paynim’s strongholds. His proposals contain a number of technological novelties, among them: zyx zyxw Machines made up of pre-fabricated elements, all portable and with some measure of interchangeable or multi-purpose parts. (2) Paddle-wheel boats propelled by crankshafts (FIGURE3). (3) A fighting-wagon or “tank” propelled by crankshafts and gears, and with a steerable front axle (FIGURE4). (4) A similar ”tank” propelled by a windmill mounted on its top (FIGURE 5). (5) Extensive structural use of iron. (I) There is little evidence that anything Guido proposed was ever attempted in practice. Structural iron, pre-fabricated parts, paddle-wheel boats, and tanks all lay in the future. But if Guido was merely an armchair engineer, he was remarkably well informed about the practices of his day. Many of the technical words he employs are unique to his treatise in their Latin forms, but they are clearly and closely related to Italian words we find in vernacular texts from a later date. Obviously Guido had been listening and observing in workshops for some time before he put pen to parchment. Even his most outlandish suggestion, the windmill-powered armored vehicle, shows that he understood well the craft basis from which his proposal grew, i.e. the business of the millwright. He was also apparently capable of independent invention, for his crankshafts are the first of their type anywhere, and they do not reappear for nearly a century (and then only as the carpenter’s brace-and-bit). We cannot be certain that French carpenters of the 1 3 3 0 s did not have the brace-and-bit, but even if Guido borrowed from such a source, his adaptation of the crankshaft to propulsive purposes is itself a significant act of inventive intelligence. If we seek some tradition to which Guido might be related, we have difficulties that did not arise in respect to the instrument treatises. There is no strong or well-defined body of works to which the Texaurus seems closely related. There are, to be sure, noteworthy books on military affairs zyxwvu zyx HALL: GIOVANNI DE'DONDI AND GUIDO DA VIGEVANO zyxw FIGURE4. Guido's crankshaft-powered fighting wagon or "tank'. The drawing is deliberately distorted to display the mechanism. With permission of the Bibliothkque Nationale, Paris. zyxw NEW YORK ACADEMY OF SCIENCES zyxwvutsrqp FIGURE5. Guido’s similar fighting wagon equipped with windmill propulsion drive. With permission of the Bibliotheque Nationale, Paris. zyxwvutsrq zyxwvuts HALL : GIOVANNI DE'DONDI AND GUIDO DA VIGEVANO zyx 1.391 from antiquity : one thinks immediately of Vegetius, whose work survives throughout the middle ages. On the Byzantine side we have the Tactica of Emperor Leo VI (886-911). Both of these are concerned with military machines only peripherally, however. The Alexandrian writers, Philon and Heron, concern themselves with catapults, but their treatment of such weapons is firmly within the limits of the instrument treatise tradition. Apollodorus of Damascus, a contemporary of Hadrian, wrote on siegecraft, and his work was expanded upon in the eleventh century by a Byzantine author known as Heron the Younger. I am unaware, however, that either Apollodorus or Heron were known in fourteenth-century France, either in direct copies or through Latin imitators. Only that strange anonymous work of the late fourth century, De rebus bellicis, which proposes a number of imaginative, if impractical, military devices to help save a dying empire could have been a potential source of inspiration to Guido.lo It has also been recently suggested that two authors closer to Guido's own day might have influenced him: Aegidius Columna, author of De regimine principium (c. 1 2 8 5 ) and Marino Sanudo (Torsellus the Elder) who wrote his Liber secretorurn fidelium crucis super Terrae Sanctae recuperatione et conservatione between 1306 and 1313. Both works contain remarks on siege engines and fortifications, but even the author of this suggestion admits that neither work contains the kind of detailed technological information that Guido presents." Guido's relationship to tradition is therefore somewhat ambiguous, but his novel traits stand out quite clearly. He is not describing machines that he or anyone else has actually constructed; rather he is putting forth a set of proposals in specific, detailed fashion about machines that could be made in the service of a valued goal. These proposals are practical or realistic only to the degree that they are rooted in the living technology of Guido's own day; otherwise they are imaginative fantasies, contemplations of the barely possible, and, like most armchair musings, a mixture of the admirable (interchangeable components) and the ridiculous (windmill-powered tanks). This is not the place to enter into a discussion of the roIe of technological fantasies in Western thought, but it is significant that with Guido the locus of imagination begins to shift from the world of objects, such as astronomical clocks, to the realm of text. In the following century, composition of imaginative technological treatises would be carried to unprecedented lengths. Guido also heralds a new style of technological writing in his use of words and pictures. His drawings, unlike those in the instrument treatises, [1401 zyxwvuts z NEW YORK ACADEMY OF SCIENCES are not diagrams, but naturalistic illustrations (or as close an approximation as was possible in the trecento to developed Renaissance naturalism), and they figure prominently in the organization of the manuscript (see FIGURES3-5). We can learn from Guido’s figures what his machines looked like, often, alas, at the expense of some of their interesting technical details. In the fifteenth century, pictures would rise to a central position in many technological treatises, subordinating and in some cases suppressing verbal descriptions. Guido’s words were, of course, Latin, but based as I have indicated on the vernacular of the workshop; again, in the fifteenth century vernaculars would replace Latin in technological writings, possibly as a consequence of greater literacy among craftsmen in their native tongues. Finally, unlike Giovanni and the instrument writers, Guido intended his work for an audience that did not consist of technical specialists, the king and his court. The fifteenth-century treatises on technology likewise reach for an audience that was broader than just those professionally skilled in the crafts discussed. To be sure, we do not find works aimed at a very general audience until printed technological treatises appear in the sixteenth century, but the line of development toward a more public form of discourse about technology can be traced forward from Guido’s time without any break. In short, Guido da Vigevano‘s Texaurus Regis Francie,is less a representative of an older tradition of technological writings than a harbinger of new forms of such works that appear in force only in the fifteenth century.12 That Guido was known to the later writers is manifest by his patent influence on Roberto Valturio’s De re rnilifari, one of the most widely read of the new treatises and the first to reach print. Looking at him as a precursor, we can use Guido to suggest a second modification of the scholar-craftsman argument mentioned at the outset. The medieval reticence on matters technological came to an abrupt end after 1400 when a much larger number of new treatises in a new style began to appear. This development had its own dynamic and rationale, which we cannot discuss here, but we should note that these new works were written and illustrated by men from both sides of the sociological divide, by scholars and physicians, such as Giovanni da Fontana and Conrad Kyeser (the latter being extremely influential in Germany), by craftsmen such as the anonymous artillery man who composed Feuerwerkbuch (the first didactic manual for gunners), by men such as the Sienese notary Mariano Taccola, and by artist-engineers such as Francesco di Giorgio Martini and, the greatest of them all, Leonard0 da Vinci. These new writings were concerned with zyxwv zyxwvutsrq zyxw HALL : GIOVANNI DE'DONDI AND GUIDO DA VIGEVANO [wI some of the old subjects, instruments and siege engines, but they include much else besides : civil engineering, architectural matters, machine design, pumps, hydraulics, mills-the list is practically endless. Although these new treatises do not mark the end of social and intellectual distinctions between scholars and craftsmen, they do represent a more open and discursive phase in the history of our sources. The apparent existence of this open audience, combined with the fact that such works were at times patronized and collected by the wealthy and high-born as elaborate encyclopedias of technology, suggests a fundamental realignment of attitudes about technical matters. The exact outlines of these changes are still not clear to us, but the fourteenth century seems to have been a transitional period of considerable importance in bringing them about. zy zyx CONCLUSION To conclude by summarizing: I have tried to introduce some of the major types and features of medieval writings about technology by holding up two works from the fourteenth century as examples. Giovanni de'Dondi's Tractatus astrarii represents an older, more stable form of technological treatise concerned with the design and construction of relatively precise and complex instruments. This is a very well-represented species, and I have tried to account for the frequency with which such works appear (in apparent contradiction to the scholar-craftsman argument) by pointing to the intellectual roots such activities had in natural philosophy, astronomy, and mathematics. I have tried to suggest that Giovanni's work represents the medieval version of High Technology and that this was a suitable subject for scholars to write upon. Guido da Vigevano's Texaurus Regis Francie, by contrast, represents a less cultivated form of expression concerned with less exalted subjects. Guido's treatment of his material takes the form of imaginative proposals directed at an unspecialized audience. I have indicated that his work is possibly less significant in itself than in its role as forerunner of a great flood of fifteenth-century treatises on all manner of technological subjects. These imaginative and discursive works which Guido heralds are, I have argued, a new type of technological writing and they suggest new intellectual attitudes and possibly a new social arrangement with respect to technology. We do not yet have a good grasp on all these changes, but it does seem that the fourteenth century, Machaut's century, is a turning point along the road that leads to Leonard0 da Vinci, the printed works on technology of the sixteenth and seventeenth W I NEW YORK ACADEMY OF SCIENCES zyxw zyxwvutsr zyxwvutsrq zyxwv zyxw zyxwvuts zy centuries, and ultimately to the birth of modern technology in the eighteenth century. NOTES AND REFERENCES White, Lynn, Jr. Medieval Technology and Social Change. Oxford: Oxford University Press, 1962. 2. White, Lynn, Jr. ”Medieval Engineering and the Sociology of Knowledge.” Pacific Historical Review, 44 (1975). pp. 1-21. This article presents a more balanced discussion. 3 . See C. S. Smith and J. G. Hawthorne, ”Mappae clavicula: a Little Key to the World of Medieval Techniques.” Transactions of the American Philosophical Society, N.S. vol. 64, pt. 4 (i974), pp. 14-20 for an example. 4. Bedini, S. A. and F. R. Maddison. ”Mechanical Universe: The Astrarium of Giovanni de’Dondi.” Transactions of the American Philosophical Society, N.S.Vol. 56, ~ t5 ., (1966). 5 . Price, D. J. de S. “On the Origin of Clockwork, Perpetual Motion Devices and the Compass.” Bulletin 218: Contributions f r o m the Museum of History and Technology. Washington, D.C., Smithsonian Institution (i959), pp. 82-112. Also Price, D. J. de S. ”Gears from the Greeks: the Antikythera Mechanism-a Calendar Computer from ca. 80 B.C.” Transactions of the American Philosophical Society, N.S. Vol. 64 (1974). p. 7. 6. Price,5 pp. 96-102. Also T h e Book o f Knowledge of Ingenious Mechanical Devices by Ibn al-Razzaz al-lazari. Ed. and Trans. D. R. Hill, Dordrecht and Boston: D. Reidel Publishing Company, 1974. 7. North, J. D., ed. and trans. Richard of Wallingford: An Edition of His Writings. 3 Vols. Oxford: Clarendon Press, 1976. 8. Hall, A. R. “Guido’s Texaurus, 1335.’’ In On Pre-Modern Technology and Science. Eds. B. S . Hall and D. C. West. Malibu, Ca.: Undena Publications, 1976, pp. 11-52. 9. White, Lynn, Jr. ”Medical Astrologers and Late Medieval Technology.” Vintor, 6 (19751, P. 300. ID. Thompson, E. A. A Roman Reformer and Inventor. Oxford: Clarendon Press, 19-52. 11. Hall, A. R.,8 p. 12. 12. Hall, B. S. ”Der meister sol auch kennen schreiben und lesen: Writings about Technology, ca. 1400-ca. 1600 and Their Cultural Implications.” In Early Technologies. Ed., D. Schmandt-Besserat, Malibu, Ca.: Undena Publications, 1978. 1. zyxwvu zy DURING GUILLAUME DE MACHAUT’S 77-year life span, manuscript illumination in France underwent many important changes both in style and in subject matter. When Machaut entered the Luxembourg family’s service, the height of fashion in court circles was the mannered, precious, punctilious style of Jean Pucelle, and so it remained until the end of the century. However, during the reigns of Phillip VI and John I1 a different, more vigorous and realistic style appeared, which blossomed under Charles V. Several artists and groups of artists sharing the same aesthetic creed were urged by common necessity to visually translate philosophical concepts and practical subjects into manuscript decorations. Several manuscripts of Machaut‘s works exemplify this important turning point in French illumination. MPC zyxwvu