developments during the Middle Ages. The forces that stimulated technological
innovation and the full impact of that innovation upon medieval industry, economy, and
life are matters of debate, but what can be shown here is the variety of mechanisms and
their uses, as well as their ingenuity. French millers clearly made significant
contributions.
Roman Gaul doubtless received the full range of ancient milling technologies,
including not only human- and animal-driven grinding and crushing machines, used,
respectively, to make flour and oil, but also the water-powered grain mill employing a
vertical axle that in turn moved the flat-rotating grinder. Nowhere was this latter machine
used more effectively than in the 4th century at Barbegal, near Arles, where a
concentration of sixteen grinders, each driven by its own wheel, produced what is now
reliably estimated to be nine tons of flour in a twenty-four-hour day. The continued and
expanded use of water-powered grain mills is traceable through the Merovingian,
Carolingian, and subsequent medieval periods in France, in some cases displaying an
intensity of industrialization more pronounced than elsewhere in Europe. Nothing in the
9th-century sources compares, for instance, with the eighty-four mills at work on the
monastic properties of Saint-Germain-des-Prés at the time of Abbot Irminon (r. 800–25)
or the fifteen mills ordered to produce the flour for 450 loaves of bread per day in Abbot
Adalhard of Corbie’s statutes of 822.
Among the innovations relating to water-powered mills was their location not just on
streams, or near streams and fed by sluices, but also as floating mills anchored in riverine
currents or tidal estuaries, as stationary mills built over sluices through which tidal pools
were drained, and as bridge mills constructed normally on pilings associated with the
arches and cutwaters of a bridge. All of these variations are to be found in Europe by the
12th century, with France showing particular adaptability, the most fully documented
examples being bridge mills, origins of which can be traced there back to the 11th
century (e.g., Jumièges, ca. 1020; Angers and Mayenne, 1028) and the earliest
illustrations of which appear, however schematic or fanciful, in French manuscripts (e.g.,
the Légende de saint Denis, 1317).
Major innovations are also to be seen in the utilization of water-powered machinery in
processes other than grinding grain. Crucial here is the translation of the rotary motion of
the wheel into reciprocating motion, as of a hammer, vertical or recumbent, made
possible by cams located on the horizontal axle of the vertical water-wheel. This is first
indicated in an architectural plan produced for the abbot of Saint-Gall ca. 820, in which
the hammers adjoin a brewery and thus are seemingly intended for use in the preparation
of the malt (beer mash). The earliest documentary references to working beer mills
anywhere are from mid-9th-century France (e.g., Évreux, 862; Vaux-sur-Somme, 867);
hammers are not always specified (grinding was a practical, if less efficient, alternative in
the reduction of the malt), but water power is clearly indicated by the hydrographical
context of the relevant entries in the documents. Pounding action is undoubted in the
fulling and hemp mills that appeared during the 11th century in the manufacture,
respectively, of cloth and cordage in Italy and France, as at Lérins (1040); in the tanning
mills, for crushing the bark, that made their appearance in the 12th century in France, as
at Charment, near Paris (1138); and in the metallurgical industry. The latter experienced
the first certain use of water-powered hammers and bellows, also operated by cams, by
the 13th century in Sweden (1224), France (the Dauphiné, 1226), and Germany (ca.
Medieval france: an encyclopedia 1176