Proceedings 27 February 1992 the Warburg Institute, Woburn Square, London
MECHANICAL GENIUS OF THE FIFTEENTH CENTURY: an illustrated paper by Dr.Alex Keller of Leicester University.
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In the course of the hundred years after Konrad Kyeser compiled his 'Bellifortis’, in 1405, at least as many such manuscripts of mechanical inventions were copied or composed. In the catalogue of 123 manuscripts [including all those of Leonardo da Vinci], which Bertrand Gille appended to his 'Les Ingenieurs de la Renaissance', 34 are described as of "the German school". Bert Hall, in the introduction to his edition of a later manuscript, the so-called Anonymous of the Hussite war, lists more than ninety German MSS of this type and he calls his list only a selection. Evidently he knows of three times as many as Gille. Gille was perhaps more comprehensive in his study of Italian collections, but even if that be so, we are left with scores of mechanical manuscripts in each country. Gille actually termed four of his German MSS 'primitive', but Hall seems to regard all these as later than Kyeser, so that his, book was the first.
He had a fourteenth century predecessor in Guido da Vigevano, of whose manuscript only three copies are extant and a thirteenth century predecessor in Villard de Honnecourt, not to mention a few earlier Arabic works of similar character. But this handful of precedents just shows up the contrast with the abundance of material from 1405 onwards.
Kyeser [b. Eichstatt, 1366] was joined by two younger contemporaries, both Italian, Mariano Taccola [b. Siena, 1382], and Giovanni Fontana [probably Venetian, b.circa 1390-he graduated M.D. in 1419]. Although their subject matter does overlap, the three were clearly independent of one another; most of the machines, which appear in their pages, appear in one author only. All three have been studied for many years. Once historians began to look into the origins of artillery in the nineteenth century, these manuscripts [conveniently represented in several of the great manuscript libraries] were examined for evidence. Much more recently, detailed study of the texts was inaugurated by the magnificent Quarg edition of Kyeser [1967]. Since then a number of scholars have worked on Taccola, most recently Galluzzi. Editions have been produced by Beck [1968],Scaglia [1971] and Knobloch [1984]. Fontana has been less well served; P.L.Rose intended an edition of his MS but has now given over the task. Such leading scholars, of medieval science and technology as Thorndike, Clagett, and Birkenmajer have researched his biography and bibliography, for alone of the three inventors he wrote on many other subjects. Perhaps one reason why he has been relatively neglected is because the text of his manuscript of inventions is partly cryptographic. The code has been broken, and a transcript of decoded text exists, although actually it does not add much to the Latin captions in ordinary script. The French scholar Omont, who published his solution, also noted that the same code was used for the Paris MS Lat.635,"Secretum de Thesauro Experimentorum et Imaginationis Hominum", but he did not analyse the context, just listed the contents. Evidently much work is still to be done on Fontana.
So far, despite all the attention devoted to individual texts, no synthesis has been attempted since Gille's, which was really rather premature. Apparently he hoped it would be possible for one individual to deal adequately with all the hundred odd manuscripts, at a time when none had appeared in a critical edition. Inevitably therefore he misconstrued many points. He does tend to equate 'primitive' with medieval, and look for signs of modernity in a more rational or more representational approach. Too often indeed we look at these manuscripts in search of evidence for the first appearance of some device, or in order to decide how much was genuinely practical or original. Clearly the relationship between these manuscripts and the state of the art in the various technologies of the time is a question worth asking. But it is not the whole story. To the historian the prime questions are, why then? , why there? Why after a seventy-year gap since Guido da Vigevano do three such authors appear almost together? What do they have in common? Why is there, from then on, that abundance of copying, re-working and collecting, through to the printed anthologies of machines of the late 16th-early 17th centuries? On the other hand, why were there no such MSS drawn up in the Netherlands, which was certainly the most developed area of Europe, economically and technically? In South Germany mining and metallurgical industries flourished, but these are not at all prominent in Kyeser's manuscript, nor in his successors'.
The most ingenious 'high tech.' of the time was the mechanical clock, which had been invented, in effect, in the previous century, although a number of innovations came in during the 15th century, making timepieces smaller and more domesticated. Hardly any of this appears in these manuscripts. Those of the later 15th century are just as uninterested in the printing press, then rapidly diffusing across Europe.
So we need to explain both the sudden efflorescence of this literature, and its dissonance with what might obviously be regarded as the significant technologies of the real world.
1} Is, the answer military? Kyeser's book is after all entitled, Bellifortis. Fontana's was labelled [although not by him] Bellicorum Instrumentorum Liber. In the original list of contents, Taccola's De Machinis, is headed De Rebus Militaribus', as Knobloch has pointed out. Yet many of the engines and instruments depicted are not weapons of war. Of course, even if not military originally, many devices could have their uses in time of war. Conduits to take water to mills, or for irrigation could also divert streams into moats, or even [in theory] deprive a town of its highway of trade by diverting its river. Since then as now, armies march on their stomachs, mills too could have a military function, especially if independent of wind or water. Hand mills that could be operated in a confined space were considered essential items of a fortress' establishment. But were there more wars in the 15th century than in the 14th? Probably not. Perhaps there was a greater anxiety over the impending menace of the Turks, after the disaster of NICO polis [1396], at which Kiser may have been present. Ingenious devices might make up for a perceived lack of manpower in such a confrontation. Certainly Taccola insists that his more dreadful fantasies are only for war against the infidel, and he deplores conflicts among Christians.
Artillery was now beginning to make a real difference to warfare. Does that help to explain? Kyeser does include several guns in Bellifortis, and conceives methods of firing whole batteries of guns together or in quick succession. Taccola and Fontana also include some guns, but not many-it could not be said either was excited by the new arm of war. Fontana's enthusiasm was rather for applying the reaction from the explosion of a charge of gunpowder to shoot a rocket or a jet-propelled trolley so as to measure ground or height, which could not be approached safely. Instead all the old pre-artillery techniques are still there, in all three authors: trebuchets, scaling ladders, siege towers, assault craft for crossing moats or streams, battering rams, mobile shelters to protect advancing infantry. So the new arsenal does not replace the old, but at most complements it...Can this literature then be a response to the spread of cannon?
2} Lynn White proposed that as medicine became more and more the prerogative of the university-trained physician, so these learned medics set more store by astrological diagnosis, prognosis and even cures. That would have obliged them to learn some astronomy and
some mathematics. A few would then have extended their interest to those devices that required mathematical training. Successful physicians attended on princes and nobles and accompanied them to war. Perhaps they were then inspired to apply the same intellectual skills to the development of weaponry. Two of the authors, Kyeser and Fontana, were doctors, and Kyeser shows every sign of being an enthusiast for astrology. However, as has been pointed out, none show any mechanical clocks, although these novel machines were so closely linked to the study of the sky.
3} Was this literature inspired by the study of Classical sources? The influence of Vegetius is manifest; probably also that of another inventor of the late Roman Empire, the Anonymous De Rebus Bellicis. Both believed that ski1ful strategy and mechanical ingenuity might compensate for the weaknesses of the Roman army. Was there any knowledge of the ancient Greek authors of Belopoiica', and Poliorcetica? Would they then have been accessible, or widely known? Perhaps by reputation? Our authors do claim to have studied the ancients, and even improved on them; they also claim to have experimented on their own account.
4} Can we even see traces of Asian influence? Kyeser shows us a kite, or rather windsock, in the form of a fire-breathing dragon; Fontana refers to Al-Kindi, speaks of Persian or Saracen fountains. Taccola attributes a rag-and-chain pump to the Tatars. Perhaps all were curious about Oriental knowledge, and liked to think they had rediscovered the secrets of the east. But there is little evidence for any real direct inspiration.
In the end our question cannot yet be answered. All were rooted in their own times, yet all were remarkably individual style.
The digest of his paper was kindly provided by Dr.Kel1er.