University of Virginia Library

V. 15

FACILITIES FOR GRINDING,
CRUSHING, & PARCHING OF GRAIN

V.15.1

THREE IDENTICAL BUILDINGS FOR
DIFFERENT FUNCTIONS

Along the southern edge of the monastery, directly behind
the Bake and Brew House for the Monks, are ranged three
rectangular structures which house the apparatus needed
in the three main phases of preparation of bread and beer:
the grinding, crushing, and parching of the grain (fig. 438).
Only one of these, the Drying Kiln, is identified by a
descriptive legend: "the place in which the grain is
parched" (locus ad torrendas annonas). The purposes of the
other two may be inferred from their equipment, which
consists of two large "mortars" (pilae) in one, and two
"millstones" (molae) in the other. The buildings are identical
in shape and may be assumed to be of identical construction.
They measure 35 feet by 35 feet and are internally
subdivided into a principal work space 25 by 35 feet, which
contains the basic machinery, and a lean-to 10 feet wide,
serving as the dormitory for workmen (eorundem famulorum
cubilia). As in the more elaborate structures of the Plan,
the servants' quarters are not accessible from the outside,
but from the interior only. We assume that in their
exterior appearance these buildings looked much like the
mill shown in the background of the painting Seated
Madonna by Gerhard Memling (fig. 439A), now in the
Uffizi at Florence.[471] This painting also gives us an idea
about the device used to provide power in the operation
of mills and mortars—a subject that is controversial and
requires further explanation.

V.15.2

THE MILL

MAN-, ANIMAL-, WATER-POWERED?
THE ROMAN TRADITION

Ferdinand Keller referred to the molae of St. Gall as
"hand mills."[472] Albert Lenoir expressed the same view:
"The place they occupy in the room, as well as the absence
of any sort of motor mechanism in the vicinity, permits no
doubt that these mills were operated by the hand of man."
He felt convinced that they were similar to a type of mill
common among the ancients, which was set in motion by
driving the upper stone on a center spindle with a wooden
bar (fig. 440).[473] For commercial purposes the Romans used a
larger variation of this type of mill; its size required
the strength of a donkey or horse to turn it, or lacking
such beasts of burden, it was turned by slaves (figs. 441442).
In the first century B.C., these devices found a
powerful rival in the water mill.[474] Among the Roman water
mills two basic types can be distinguished: the vertical
mill (fig. 443A), in which the millstone is turned by means
of a water paddle attached to the lower end of a vertical
spindle; and the horizontal or "Vitruvian" mill, the type
in which a vertical water wheel is mounted on a horizontal
axis, from which its rotation is transmitted to the millstone
spindle by a pair of cogwheels (fig. 443B). The vertical mill
is typologically the more primitive form, and therefore
considered by some to be the earlier one.[475] The "horizontal"
water mill was probably a Roman invention, and
judging from Vitruvius' description (23-25 B.C.), it was
still a relatively recent phenomenon at the time of his
writing. The earliest water mills of the city of Rome
apparently were installed in the Tiber "a little before
Augustus,"[476] but for the first three centuries of the Empire
man-powered or animal-driven mills remained in the
majority.[477] It was only from the beginning of the fourth
century onward that the water mill began to supersede the
earlier forms. The earliest pictorial representation of the
Vitruvian water mill is to be found on a fifth-century

[ILLUSTRATION]

439.A GERHARD MEMLING. SEATED MADONNA

FLORENCE, UFFIZI GALLERY. DETAIL

[Courtesy of the Gabinetto della Soprintendenza alle Gallerie]

The painting shows in the background a Northern waterwheel in a form that the
artist perceived it; the work, probably about mid-15th century, cannot be dated
with precision.

mosaic of the Great Palace of Byzantium,[478] but an actual
mill dating from the time of Leo I (457-474) has recently
been excavated in the Agora of Athens.[479] As early as A.D.
370 water-driven corn mills and saws for cutting marble
were seen by Ausonius on the Ruwer, one of the tributaries
of the Moselle River.[480] An intensely industrial application
of water power for the grinding of grain was a
Roman flour factory with sixteen wheels, erected 308-316
on a mountain slope at Barbegal near Arles (fig. 444). It
worked with two sets of eight overshot wheels, fed by two
channels of water from the aqueduct of Les Beaux, and
could produce in a ten-hour day, with all wheels in operation,
a total of twenty-eight tons of flour, sufficient to feed
a population of 80,000—which fact suggests that it supplied
the entire army of the province of Narbonne (besides
meeting the local demands of Arles, which had a population
of 30,000). There is archaeological evidence for the
existence of a similar flour mill at Prety (Pistriacum), near
Tournus, Burgundy, which ground the grain of the Saone

[ILLUSTRATION]

439.B GERHARD MEMLING. MADONNA AND CHILD

LONDON, NATIONAL GALLERY. DETAIL

[Courtesy of the National Gallery, London. Photo no. 61275]

The waterwheel in the London version of the painting is substantially of the
the same design, and shows with greater detail some of its construction. This
painting dates to about 1468.

valley and may have been the principal source of flour
supply for the army of northern Gaul.[481] These two facilities
were unusual and owed their existence, unquestionably, to
pressing military demands, but their existence nevertheless
denotes a general trend.

The historical motivations for this mounting interest of
the fourth-century Romans in water as a source of power
for grinding grain are still somewhat mysterious. One cause
was, without doubt, the increasing shortage of slave labor
in the later days of the Roman empire; another one, the
new attitude toward labor associated with the Christian
concept of caritas, resulting in the view that the forces of
nature should be captured and trained to ease the life of
man; still another cause, perhaps, was the fact that the
center of cultural gravitation had shifted from the Mediterranean
basin, where most rivers carry widely varying
quantities of water in different seasons, to a northern area
that abounded with mountain streams fed by a constant
flow of water. Finally, but not least to be contended with:

[ILLUSTRATION]

440.A, B, C, D HAND OPERATED ROMAN MILLS

Stationary or portable mechanisms like these shown above were used in every
Greek and Roman household and were diffused throughout Europe by Greek and
Roman armies. In Roman military camps, where soldiers ground their own corn,
such handmills were a common sight. One mill was provided for every ten men;
each soldier was prepared to carry his own thirty-day flour supply (Forbes, 1956,
109; Moritz, 1958, 116; Horn, 1975, 223, and 231, fig. 7).

The upper stone, in examples A, B, C, D,
weigh, respectively, about 130, 55, 30 and
45 pounds. Quern A, with two handles, could
be operated by two persons. Quern D, a great
advance in the art of milling, provided for
adjustment of the upper stone by an under-table
device that controlled clearance between
stones at their outer rims, thereby regulating
the fineness of the milled particles. Advances
in the arts of military machines were paralleled
by invention in the agrarian arts.

the inventive freshness of the barbarians of the north, who
were not slow in putting into the service of their growing
manorial economy technological devices that offered new
prospects of exploitation to the landlords who had the
right and means of building and of operating these mills.[482]

[ILLUSTRATION]

ROMAN MILL IN POMPEII

441.A

441.B

[After Mau, 1908, 408, fig. 237]

The mill of Pompeii operates on the same principle as the table pepper mill. Its
lower fixed stone (meta) is raised on a plinth that also forms a basin to catch freshly
ground flour. The mill is charged with grain at the top; kernels fall into the space
between the two stones (which can be enlarged or decreased by adjusting the spindle
of the moving stone, the catillus, on its overarm) and are ground at the lower edge of
the catillus flange where it touches the meta.

[ILLUSTRATION]

441.C ROMAN DONKEY MILLS

POMPEII. REMAINS OF A ROMAN BAKERY WITH

FOUR DONKEY MILLS AND A BAKING OVEN

[after Forbes, 1956, 110, fig. 77]

Donkey mills are known to have been used in Greece from about 300 B.C. They
could be set up anywhere on land, and for that reason became the favorite Roman
flour mill. The turning circles the animals were forced to follow in this and other
mills of the type were brutally narrow.

[ILLUSTRATION]

442. ROME, MUSEO CHIARAMONTI. FRAGMENT OF A SARCOPHAGUS (2nd cent. B.C.)

HORSE HARNESSED TO A DONKEY MILL

[By courtesy of the Archivio Fotografico delle Gallerie dei Musei Vaticani]

The relief shows the hourglass shaped mill being worked by a horse harnessed to a trace that fits into the rotating upper stone of the mill (cf.
fig. 441. A). The question of the relative distribution of water- and animal-powered mills in medieval Europe, and their differing functions,
requires a new systematic study. In an inquiry into conditions prevalent in certain Carolingian territories west of the Rhine, Weber reaches the
same conclusions that Bennett and Elton came to more generally:

"Wenn man die urkundlich nachweisbaren Standorte berücksichtigt, weiss man auch, dass es sich bei unseren Beispielen nur um Wassermühlen
gehandelt haben kann. Die von Tieren getriebene Mühle bleibt fortab die Ausnahme. Sie wird meist nur für Notfälle eingerichtet, z.B. auf
Burgen und ummauerten Städten für die Zeiten langdauernder Belagerungen." (F. W. Weber, "Die ersten urkundlich nachweisbaren
Wassermühlen westlich des Rheins," Pfälzer Heimat, vol. 3/4, Dec. 1972, 101-103. The journal is not easily available outside Germany.)

[ILLUSTRATION]

ROMAN WATER MILLS

443.A Horizontal water wheel at the end
of a vertical shaft fixed to the
upper millstone.

443.B Vertical waterwheel, with power
transmitted to the upper millstone
by means of gears.

[redrawn by C. B. Lund, after Forbes 1956, 595, fig. 540]

The earliest water mill of which we have any record is one to which the Greek
historian Strabo refers as having been built by the Pontic king, Mithradates VI
Eupator, in his palace at Cabeira (some distance inland from the southern shore
of the Black Sea), which was completed in 63 B.C. (For sources and a
suggestion that this may indicate an Asiatic origin, as in the case of the water-powered
triphammer, see Horn, 1975, pp. 226-27 and below, pp. 245f.)

THE MONASTERY A PRIMARY AGENT
IN THE HARNESSING OF WATER POWER AND IN
DIFFUSING ITS USE

The medieval monastery, a leader in all other aspects of
rural economy, became one of the primary agents in the
dissemination of water power for the grinding of grain as
well as for many other uses. The earliest transalpine water
mill put to monastic use is recorded by Gregory of Tours
at the time of the Visigoth ruler Alaric (484-507).[483] This
account is of particular interest, since it tells us how, during
and for a short time after the construction of the monastery
of Loches (Indres-et-Loire) by Abbot Ursus, "the brothers
ground the wheat required for their sustenance by turning
the millstones by hand" (molam manu vertentes). Ursus
decided to supplant their labor by constructing a mill at
the banks of the river Endria: "Setting stakes across the
river and heaping a great pile of large stones, he built
sluices, gathered the water in a channel, and by its impetus
thus drove the wheel of the work into swiftly spinning

motion" (cuius impetu rotam fabricae in magna volubilitate
vertere fecit). Another water mill is mentioned by the same
Gregory of Tours in his description of the city of Dijon.[484]

More evidence (so far overlooked) attesting the rapid
spread of use of water mills in Merovingian Europe may
be found in the Lives of Father Romanus (fifth century),
of St. Remy (ca. 437-533), and of Athala, Abbot of Bobbio
(615-627).[485] The availability of water for the operation of a

[ILLUSTRATION]

445. HERRADE DE LANDSBERG. HORTUS DELICIARUM (1195), fol. 112A

(formerly) STRASSBOURG, BIBLIOTHÈQUE PUBLIQUE

[after Straub and Keller, 1901, pl. xxx]

Two women attend a water-powered mill. This illustration
is after a postmedieval copy of a manuscript that was
destroyed during the Franco-German war.

mill and other monastic workshops was a crucial factor in
situating a monastery which Count Wibertus and Countess
Ada, during the reign of King Pippin, erected for their
daughter St. Hiltrud (d. ca. 790) at Liessies.[486] Two water
mills on the Leto River were given to the monastery of
Aniane by Charlemagne in a donation charter dated Aachen,
June 799;[487] another one in the vicinity of Dover is mentioned
in a charter of King Ethelbert, dated 762.[488] The
context of the chapter in which Abbot Adalhard in 822
defines the duties and privileges of the millers employed
by the Abbey of Corbie and its various dependencies leaves
no doubt that he is referring to water-powered mills, since
he stipulates that the millers be furnished, inter alia, with
everything that is required for the maintenance and repair
of their sluices (sclusa).[489] The Abbey of St.-Riquier in 798
had a water-driven mill which received its power from a
small stream called Scarduo running through the middle
of the monastery.[490] From the ninth century onward references
to water mills are made with increasing frequency.
An interesting incident in connection with the establishment
of water mills is the account of the failure of Abbot
Habertus of Laubach (d. A.D. 835) to cut an aqueduct to
channel water to the mills through the rugged slopes of the
mountain which surrounded his monastery.[491] In the centuries
that follow, references to water mills become legion.
The Domesday Book (ca. 1080) lists 5,624 of them.[492] From
the twelfth century on they are frequently depicted in
illuminated manuscripts. In the precision of their detail,
some of these representations compare favorably with
modern engineering drawings; (cf. fig. 445).[493]

EVIDENCE FOR A WATER-POWERED MILL

In the light of this abundant and clear evidence, Keller's
and Lenoir's opinion that the mills of St. Gall were hand-operated
mechanisms seems quite open to debate. What
Keller had in mind, I should think, was the kind of hand
mill that is depicted in a German manuscript of the fourteenth
century (fig. 446), reproduced by Bennet and

[ILLUSTRATION]

446. MEDIEVAL HAND MILL

The drawing, from a German 14th-cent. manuscript, shows a mill
derivative of the hand-operated Roman mill (fig. 440. A, B) that
survived the advent of the watermill.

[ILLUSTRATION]

447. HAUSBUCH MASTER. MILLING APPARATUS

CA. 1480

[after Bossert and Stork, 1912, pl. 46]

Although the drawing is rendered in the clumsy perspective of a
Middle Rhenish master of the pre-Dürer period, it portrays the
milling mechanism with great factual accuracy. The pen and ink
drawing appears in a manuscript written and illustrated by an
official who in 15th-century Germany was called "Büchsenmeister"
—master of firearms. Of relatively high social standing, such a
personage would today hold a position comparable with civil or
military engineer. (The manuscript is the property of Fürst
Waldburg-Wolfegg-Waldsee.)

[ILLUSTRATION]

448.B, C PLAN OF ST. GALL. MILL

AUTHORS' INTERPRETATION. GROUND PLAN

Waterpower for the Mill and Mortar of the Plan of St. Gall is a viable proposal; we have therefore reconstructed the mechanisms as water driven, for these reasons:
As regards the millstones, their size, at a literal diameter of 7½ feet, would tend to eliminate the possibility of hand operation. Their depiction on the Plan lacks any
indication of drive systems, but that lack is consistent with other such omissions where practicalities, to be left to a master craftsman to execute, have been eliminated in
favor of clarity of scale and function.

The alignment of mills and mortar on the southern edge of the Plan site would facilitate use of water power assuming that a stream existed on the site and could be
channeled down a gradient sufficient to provide it (cf. I, 68-69 and fig. 53). Abundant documentary evidence shows that from the end of the 5th century onward and
with increasing frequency in succeeding centuries, monastic mills of transalpine Europe were water powered; finally, references to animal-driven mills in these some
sources are almost entirely lacking (see above, p. 228, fig. 442 caption).

We have already discussed the question of why the Romans, although they had it, made scant use of the water mill; whereas the young barbarian nations of the north
adopted and diffused it with enthusiasm. To reasons already set forth we suggest here, as a factor so far overlooked, that the strongest impetus for the phenomenal spread
of waterpower in the early Middle Ages came not from the secular world but from the ascendancy of Benedictine monasticism.

The records of many abbots show that extensive monastic estates included mills located far outside the immediate vicinity of the monastery; Gozbert himself doubtless
would have controlled several beyond the two proposed by the Plan for the monastery. Adalhard records that Corbie's bakeries had to produce 450 one-pound loaves
each day, for which the monastery drew on an annual volume of 5,475 modii of grain from 15 mills, each of six millstones, all of which had to be maintained in good
working order (see III, 106-107). And the abbey of St.-Germain-des-Prés had several times again that number of mills (see Horn, 1975, 248ff, for details and sources.)

Building and operating such facilities required impressive capital investment dependent on ownership of great acreage and an unparalleled degree of managerial
competence. The monastic school-trained leaders of the period brought to the vast monastic holdings the ingenuity and spirit of radical innovation that necessity alone
would have made welcome. In addition, the monastries and their high officials had the pressing moral committment to free the monks from long hours of arduous
physical labor, in order to further the Opus Dei. By contrast the secular world, lacking intellectual advantages, integrated physical resources, administrative unity, and
religious incentives, lagged behing the great monastries in technical innovation; as in most labor-intensive societies, medieval secular institutions tended toward
conservatism.

Gregory of Tours leaves as an anecdote about Abbot Ursus that constitutes the first documentary evidence of a monastic mill. After relating that "on account of this
[water mill] the work that formerly had to be done by many monks could now be accomplished by a single brother," Gregory repeats a dialogue between Ursus and
Sichlerius, a Visigoth and nobleman whose land bordered the abbey's, and who had seen first hand the installation of the new mill and its sluices:

"Covetous to acquire the mill, he told the abbot, `Give me this mill, to become my property, and I shall give you, in return, whatever you ask for,' Replied the Abbot:
`It was only with the greatest of pain, on account of our poverty, that we were able to install this mill; and now we cannot give it to you lest our brethren die of
hunger.' Sichlerius retorted: `If you wish to give it to me by your own free will, I shall be grateful. Otherwise I will take it by force, or build another mill, for which I
shall divert the water from your sluice; and in this way it will no longer be able to turn your wheel.' The abbot replied, `You will not do what God shall not permit you
to do, you will not take it at all!' Sichlerius, in ire, did what he had threatened to do, but because of divine intervention, the water failed to turn the wheels of his
mill." Thus the intransigent noble was defeated.

The story, embodying all the social dichotomies between secular and religious spheres, is symptomatic and may have remained so for the most of the Middle Ages.
Ingenuity and initiative, in addition to divine justice, were clearly on the side of the abbot.

[ILLUSTRATION]

PLAN OF ST. GALL. MILL

448.D LONGITUDINAL SECTION

448.E TRANSVERSE SECTION

AUTHORS' INTERPRETATION

Elton.[494] It is obvious that two hand-operated units of this
type could never have produced the volume of flour needed
in a settlement the size of that represented on the Plan of
St. Gall. Hand-operated mills, because they were subject
to the limitations of manual operation, were bound to be
small. Yet the millstones of the Plan are not only large,
they seem colossal. They are drawn at a diameter of 7½ feet.
Even if the representation is not literal,[495] such weight and
volume could not possibly have been set in motion by manual
operation. There are other factors suggesting water power.
The drafter of the Plan, as we have seen, did not consider it
part of his task to include a delineation of the monastery's
water system, but he was not oblivious to the fact that
buildings requiring water power would have to be located
in places to which water could easily be conducted. This is
clearly indicated by the way he carefully aligned all the
buildings and activities requiring water along the edge of

[ILLUSTRATION]

449.C LUTTRELL PSALTER (1340). LONDON, BRITISH MUSEUM. ADD. MS. 42130, FOL. 207

BY COURTESY OF THE TRUSTEES OF THE BRITISH MUSEUM

A cook tends his kettles and his assistant wields choppers; at the right a third man macerates some substance with a long pestle in a large
container. It is not clear whether he is pounding meat (as Millar, 1932, 49, thought), crushing grain, or churning butter.

the monastery in a manner that, were a water source available,
it could have been channeled to serve all of them
efficiently.[496]

RECONSTRUCTION OF MILLING APPARATUS

The reconstruction of the milling apparatus poses no
major problem, since both Herrade de Landsberg (1195)[497]
and the Hausbuch Master (ca. 1480)[498] have furnished us
with very detailed drawings of water-driven milling mechanisms
(figs. 445 and 447). Herrade's mill is undershot. A
large waterwheel transmits its rotation through an axle to
a smaller wheel, the cogs of which are geared into a vertical
drum. The vertical power of the driving wheel is thus converted
into the horizontal motion of the millstone. A hopper
feeds the grain from overhead into a hole in the center of
the upper stone, the so-called "runner". This system is
essentially the same as that of the so-called Vitruvian mill,
except for a difference in the speed of transmitting power.
The Vitruvian mill is relatively small and moves faster
than the wheel that turns the millstone. In the medieval
mill, with its larger waterwheel, the transmission is from
slower to faster.[499] In our reconstruction of the Mill of the
Plan (fig. 448A-E) we have adopted the latter system.

The Mill of the Plan would have taken care only of those
milling operations which were performed within the monastic
enclosure. On its outlying estates a monastery usually
operated a great number of additional mills. According to
Guérard's calculations, at the time of Abbot Irminon (ca.
800-826) the Abbey of St.-Germain des Prés managed as
many as eighty-four mills on its outlying estates.[500] The

[ILLUSTRATION]

HAND-OPERATED MORTARS AND PESTLES
OF OAK

449.A.1

449.A.2

[after Keller, 1860, 45 and 50]

BELTIS, LAKE WALLENSTADT, SWITZERLAND

Devices of this kind, used for crushing cereal grains, were in the Middle Ages
employed in every household; porridge made from these grains was one of the
principal items in the common man's diet.

status of the millers in charge of these installations, to
judge from the Administrative Directives of Adalhard of
Corbie, differed from that of the other monastic tenants in
that they were exempt from the manual labor to which the
other tenants were held, such as "plowing, sowing, harvesting
grain or hay, making malt or hops, delivering wood
or anything else in the service of the lord" (ad opus
dominicum).[501] Adalhard stipulates that each miller was to
be provided with a pair of oxen and other things necessary
for the sustenance of himself and his entire family, so that
he could raise pigs, geese, and chickens, and set up his
mill, and might obtain or manufacture all such materials
as he needed in order to improve his mill, repair his sluice,
transport his millstone, and everything else that he might
need to own or manufacture.[502]

[ILLUSTRATION]

449.B LE THORONET, VAR, FRANCE

MORTAR AND PESTLE

Hand mortars of this kind continued in use in the Middle Ages along with
water-powered trip hammers (figs. 454, 457), and were important in seasons
when streams were too low to drive trip hammers.

[ILLUSTRATION]

450. MODERN TRIP-HAMMER

[redrawn after Meringer, 1906, 16, fig. 26]

Trip-hammers of this type are used even today in areas stretching from Central
Europe throughout the whole of Asia, as far as India, China, and Japan. The
hammer shown is of the foot operated type.

V.15.3

THE MORTARS

MAN- OR WATER-POWERED? CONFLICTING VIEWS

The crushing devices designated by the term pilae, i.e.,
"pestles," in the house lying west of the Mill (fig. 438),
raise the same problems posed by the milling apparatus.
Were they operated by hand or water? Keller, in this case
too, took the first position. He drew attention to two old
hand-operated mortars which he discovered in the remote
village of Beltis on the lake of Wallenstadt in Switzerland
(fig. 449 A.1, A.2).[503] One was three feet high, cut out of a
solid trunk of oak, with the interior hollowed out conically.
The pestle, likewise, was made of a single piece of oak,
except for its handle, and was studded with nails at its
base. This, Keller thought, must have been the contrivance
that the drafter of the Plan of St. Gall had in mind when
he drew his peculiar L- or key-shaped pilae (fig. 438).

[ILLUSTRATION]

451. HOKUSAI. JAPANESE TRIP-HAMMER (19th cent.)

[after Singer, Holmgard, Hall, II, 1956, 107, fig. 71]

If his expression of grim determination is an indication, the man acting as
counterweight to the hammer could scarcely have worked harder using a mortar
and pestle for his task.

That instruments of the Beltis type were used during the
Middle Ages is beyond question, and easy proof of this
may be found inter alia in a delightful marginal drawing
of the Luttrell Psalter (fig. 449C), which shows a bearded
cook pounding a huge mortar with a pestle almost twice
his own height.[504] The mortar, apparently made of iron or
bronze, reaches to slightly above the knee of the pounding
cook, and by that criterion should have been meant to have
a height and width of roughly two feet. The largest implement
of that type I have ever examined is a mortar carved
of a single block of stone, that stands now in the medieval
granary of the Abbey of Le Thoronet in Provence, only a
few yards away from the millstone discussed in an earlier
part of this chapter. This mortar (fig. 449B) has a round
base, 2 feet in diameter, is 3½ feet high, and 4 feet wide at
the top. Its pounding cavity tapers from the rectangular
opening at the top to a conical form at the bottom. The
pestle—which does not look to me to be the original—is
a roughly hewn trunk of a young tree, about 9 inches thick

and nearly 5 feet high. In testing it on the spot it seemed to
me that it could be worked with some effort by a single
man, and with ease by two men lifting it in conjunction.

Yet I would be inclined to think that in the Middle Ages
mortars and pestles of this order of magnitude were water
driven, rather than hand-operated mechanisms. This was
also the view of Rudolf Meringer who has made a special
study of this type of instrument. In an article on the implements
of the pinsere series and their names, published in
1909, Meringer[505] drew attention to the fact that the pilae
of the Plan of St. Gall (fig. 438) were not only considerably
larger than those with which they had been compared by
Keller (fig. 449A) but also of vastly different shape. He
claimed that, rather, they bore striking resemblance to a
type of crushing device which in German is called Anke,
and illustrated his views by a startling juxtaposition of the
pilae of St. Gall and a drawing of a modern water-driven
iron hammer (fig. 453).[506] The earliest pictorial representation
of a water-driven recumbent western tilt-hammer
appears to be a woodcut in Spechthart's Flores Musicae,
published in 1488 (fig. 455).[507] In an earlier period this contrivance
was operated by hand or foot, as it was still in very
recent times in Galicia (fig. 450), Poland, China, and
Japan in very much the manner in which this is depicted
in a whimsical drawing by the Japanese painter Hokusai
(fig. 451). Man-powered tilt-hammers of this type, as was
subsequently shown, were used in China in remote periods,
and their design and mode of operation is well attested by
two small models in green glazed pottery from the Han
period (206 B.C. to A.D. 220) which are now in the Nelson
Art Gallery (fig. 452A-C), Kansas City, as well as a Han
moulded brick found at P'en-shan Hsien, in the Szechuan
Provincial Museum, Chengtu (fig. 452D).[508] Meringer
was convinced that the pilae of the Plan of St. Gall
did not belong to the foot-operated type, but that they were
water driven, and he attempted a reconstruction (fig. 454),
in which the pestle beams were alternately lifted and
released for fall by the cogs of a cylindrical drum mounted
directly upon the axle of a water wheel, as in the modern
iron hammer (fig. 453). Hydraulic trip-hammers of this
or a similar design are attested for China through unequivocal
literary descriptions as early as the reign of Emperor
Wang Mang (A.D. 9-23) and through less reliable sources
perhaps even as early as the third century B.C.[509] Meringer
could not prove that the camming action employed in this
device was known in Carolingian times,[510] and his interpretation
of the pilae of St. Gall as hydraulic cam-operated
pounding mechanisms did not come to the attention of
Marc Bloch who, in his classical and widely read study on
the advent and spread of the water mill, referred to the
pilae of St. Gall as "a crushing instrument which, on the
plan, was certainly not shown as being water driven;"[511]
a view which was reiterated in 1954 by Bertrand Gille,[512]
and subsequently adopted, although perhaps not with the
same degree of conviction, by Lynn White in 1962.[513]
Finally, in 1965, it looked as though Meringer's interpretation
had received a final blow, when Joseph Needham,
in his monumental Science and Civilization in China, after
a thorough account of the Chinese history of the hydraulic
trip-hammer[514] advanced the theory that this mechanism
was introduced in Europe "about the time of Marco Polo,"
in connection with the fulling trade when much other
Chinese textile machinery appears to have made its way to
Europe. Needham proclaimed that all water powered European
stamp mills prior to that period were machines in
which pestle beams moved in vertical action in the manner
illustrated by a drawing made by an anonymous Hussite
engineer around 1430 (fig. 456).[515]

EVIDENCE FOR WATER-POWERED TRIP-HAMMERS

The Plan of St. Gall contradicts these views. The pilae
of its Mortar House can under no circumstances be interpreted
as vertical pestles. Their design—a hammer attached
at right angles to a pestle beam connecting at the opposite
end with a body of cylindrical shape—leaves no doubt
that they were recumbent hammers activated by the cams
of a revolving drum. Their dimensions as well as their
location, next to a water-driven grain mill, suggests that
they were water powered. The pestle beam alone is 10 feet
long (4 standard modules), the hammer has a length of 6
feet (2½ standard modules) and the drum has a diameter
of 6¾ feet. The over-all length comes close to 17½ feet. This
is a very heavy piece of equipment that could not possibly
be operated by hand or foot. The Plan may somewhat
exaggerate the dimensions of the drum,[516] but it leaves no

[ILLUSTRATION]

452.A MODEL. FARMYARD DETAIL WITH FOOT-OPERATED TRIP-HAMMER. HAN DYNASTY, 206 B.C.-220 A.D.

IRRIDESCENT GREEN GLAZED POTTERY, 8¾ × 6 × 2½ INCHES

question about the presence of a drum, which makes sense
only within the context of a water-powered apparatus.
Marc Bloch's argument that water is not shown on the
Plan, does not militate against this conclusion. We have
shown in our chapter on omissions and oversights how
waterways, although nowhere in evidence on the Plan,
could be a determining factor in siting of facilities dependent
on this power source, and were therefore clearly a
possibility taken into account by the designing architect.[517]

The crushing mechanisms of the Mortar House of the
Plan of St. Gall are, as far as I can see, the earliest historical
evidence of the use of hydraulic trip-hammers in Western
Europe. Their appearance on the Plan makes it clear that
water-driven trip-hammers were, at the time when the
original scheme was drawn, i.e., in 816-817, considered
standard equipment of a paradigmatic Carolingian monastery.
There is no reason to presume that the inventor of the
scheme was also the inventor of the mechanism. The
system as such may, even in Europe, have been of considerably
greater age. It may have been diffused in Frankish
times from China, as the stirrup certainly was, as the two
forms of modern horse-harnesses probably were, and as
the mechanical crank may have been.[518]

A SURVIVING MEDIEVAL HYDRAULIC TRIP-HAMMER

I feel strengthened in this conjecture by the circumstantial
historical evidence surrounding a water-powered
medieval trip-hammer that came to my attention, in the
summer of 1970, while travelling in the mountains of the
province of León in Spain. This mechanism, not only
intact but able to be operated, is housed in a smithy located
in the valley of Compludo, on the grounds of a former
monastery of that name. San Fructuosus, a Visigoth of
royal blood and the founder of Spanish monachism, established
Compludo as the first of a vast web of monasteries.
The trip-hammer owes its anachronistic survival to the

[ILLUSTRATION]

452.B

The processing of grain for domestic use
in China during the centuries just before
and after the birth of Christ in the West
reveals wholly familiar technologies and
associations. The model of the farmyard
(fig. 452. A) contains, in addition to the
trip-hammer, a small mill and what
appears to be a parching kiln built into an
enclosure wall—an association also
reflected in the Plan of St. Gall, some 6
centuries later.

The trip-hammer in the model (figs.
452.A-B) was the simplest of mechanisms;
in it is applied the principle of fulcrum
and lever actuated by direct force.

452.C

WILLIAM ROCKHILL NELSON GALLERY OF ART, ATKINS MUSEUM OF FINE ARTS, KANSAS CITY, MISSOURI

IRRIDESCENT GREEN GLAZED POTTERY, 10¾ × 3½ × 3½ INCHES

complete and utter isolation of the site, which even today,
is accessible by only a stony mountain road whose narrow
and precipitous course offers to the unexpecting modern
visitors moments of breathtaking suspense.[519] The instrument
is described by Florentino-Augustin Diez Gonzáles,[520]
in a study of the political and social life of the Spain of San
Fructuosus, which also includes a sketch of this unusual
mechanism.[521] It conforms in all respects to the trip-hammer
shown in Spechtshart's woodcut of 1488 (fig. 455)
and the modern specimen discussed by Meringer (fig. 453),
except that it is considerably larger.

The water that sets the Compludo hammer into motion
is channeled from the confluence of two narrow mountain
streams, the Miera and the Miruello, into a collecting
basin (banzao) from where it falls upon the heavy wooden
studs of a waterwheel. This wheel, 8 feet in diameter, is
driven by a shaft (árbol) made of chestnut, 16 feet long
and 2½ feet thick. Rotating horizontally this timber,
hardened by age like stone, activates with its wooden cogs

[ILLUSTRATION]

452.D CHENGTU, SZECHUAN, PROVINCIAL MUSEUM

RUBBING, CLAY TOMB TILE, (46 × 28cm) DETAIL, EASTERN HAN PERIOD, 23-220 A.D.

[after Liu Chih-yuan]

Two men are shown pounding rice with trip-hammers, a scene of daily life of the lower social strata of Chinese society that artists of the
Eastern Han loved to portray.

The tile was excavated in 1956 at T'ai-p'ing-hsiang, P'enghsien, Szechuan Province. It was published in Ssu-ch'uan Han-tai hua-hsiang
pei-t'o p'ien (Portfolio of Han Dynasty Impressed Clay Tiles from Szechuan), Ssu-ch'uan sheng po-wu-kuan (Szechuan Provincial
Museum) by Shang-hai jen-min mei-shu ch'u-pan she (Shanghai People's Art Press), 1961, pl. 3, from which this detail is taken.

[ILLUSTRATION]

453. MODERN TILT-HAMMER (SCHWANZHAMMER)

PLAN AND SIDE ELEVATION

[redrawn after Meringer, 1907, 285, fig. 10]

The cam block driving the hammer can be linked to a drive system
as sophisticated as one powered by steam, or as simple as one driven
by an animal on a treadmill.

a sturdy lever (palanca), 13 feet long, at whose extremity the
smashing hammer (mazo) rises and falls. The rhythm or
beat of the stamp can be controlled from within the forge
by a second mechanism that augments or decreases the flow
of the water turning the wheel, as the varying nature of the
work requires (sketched roughly in Gonzáles's drawing).
The ore is smelted in the furnace by a fire fanned to intense
heat by means of air drafted into it by hydraulic action
(shown in the background of Gonzáles's sketch) and under
the beat of the hammer, converted into malleable iron.[522]
To watch this primordial mechanism in operation was
truly an awe-inspiring experience.

MONASTIC ECONOMY AND WATER POWER
UNDER ST. FRUCTUOSUS

The date of the hammer is unknown.[523] Local tradition
ascribes it to "Romanesque period" (edad romanica).

González believes that mechanisms of this type might well
have been an integral part of the monastic economy of the
time of San Fructuosus (d. 665).[524] This view is not so

[ILLUSTRATION]

455. SPECHTSHART. FLORES MUSICAE

STRASSBOURG, 1488, fol. 7v

[courtesy of the University Library, Freiburg i. Br., Germany]

The woodcut shows an iron forge with a water-powered tilt-hammer
activated by a cylindrical cam block mounted on the axle of a waterwheel.
Two blacksmiths forge iron on an anvil with the hammer's
aid; behind them Pythagoras weighs hammers. In the background,
Tubal chisels musical notes into a column, representing Pythagorean
philosophical preoccupation with order, number, and harmony of the
spheres of the Ptolemaic universe (cf. I, 231, fig. 187).

shocking as it might appear to be at first exposure. The
seventh century, as has been shown in the preceding
chapter, was the great century of systematic application of
water power to milling in the economy of coenobitic
monachism.[525] The development was spurred by the need to
provide great quantities of flour for the sustenance of large
numbers of men whose religious activities required that they
be freed from certain common forms of labor, in order to
devote themselves to the more serious task of serving God
in prayer and chant. It is not an unreasonable conjecture
that the same need may also have fostered the invention or
adoption of the cam which made it possible to harness water
for tasks requiring the crushing blow of a rising and falling
mechanical hammer. It is quite possible that this idea (or
its adoption) was first conceived in connection with iron
works where the brutal blow of a hydraulic stamp offered
advantages highly superior to those that could be derived
from its use in the lighter task of crushing grain or of
fulling cloth. The banks of the rivers in the mountains of
Eastern Leon, where San Fructuosus founded his first
monasteries, carry iron deposits important enough to be
mentioned by Pliny the Elder and other Roman writers;[526]
numerous localities in this area, now in ruins or deserted,
carry even today the name herrería (iron forge).[527]

The Fructuosan monastic economy formed an ideal
ambiance for the invention of such a power mechanism. It
created a sudden and vast demand for agricultural tools by
converting virtually overnight deserted valleys into densely
populated rural communities, formed not only by the
multitude of monks that settled in the monastery itself, but
in addition by a veritable army of secular followers who
were allowed to establish themselves as tenants in the vast
stretches of land which the monastery owned in the valleys
and mountains around it. Among them were members of
the former household of San Fructuosus (whose paternal
inheritance was enormous), magnates from the royal court
with their entire families, soldiers from the Visigothic
army who fell under the spell of the saint, and in a mystical
commotion that had no precedent, followed him in such
numbers that their chieftains found themselves compelled
to legislate against such wholesale desertion of the army
and flight into the country.[528] A blacksmith capable of
converting ore into iron with the aid of water power and
shaping it into usable tools could meet the demands created
by such a sudden population increase in the country, and the

[ILLUSTRATION]

VALLEY OF COMPLUDO, LEÓN, SPAIN. MEDIEVAL IRON FORGE & WATER-POWERED TRIP-HAMMER,
WITH FORGE BLOWER ASSOCIATED WITH FLUME. Date of the initial installation unknown,
concept possibly dating from Visigothic period. See caption above.

457.A

PERSPECTIVE VIEW

In 1975 we paid another visit to the Compludo
forge and discovered that the trip-hammer we
first inspected in 1970 was being rebuilt, and the
waterwheel replaced by a slightly sturdier one.
The hammer had been moved to the outside yard
to serve as a template for its replacement. The
sturdy cammed trunk, strongest member of the
mechanism and subject to great torsional strain,
was considered in good enough condition to serve
another span in the life of the hammer. It had
earlier been reinforced lengthwise by iron bars
banded to it with iron hoops.

The carpenter directing the work was convinced
that in continuous use, wheel and hammer would
need replacement every 40 years, the main trunk
every century. He shared local belief that the
mechanism is medieval and would tend to retain
its original design for a virtually indefinite span
of time, even though its components were
periodically renewed.

These drawings were made with aid of measurements
taken in 1975. They do not show the
apparatus governing the flow of water to the
wheel and thus the speed of the hammer's
action. For rough sketches of that mechanism
and the means by which air is drafted into the
forge furnace, a function also associated with the
flow of water to the wheel race, we still depend
exclusively on the drawing published by
Gonzáles (1966, 46) and reproduced by Horn
(1975, 245).

457.B

457.C

457.D

presence of ore in these places would give an added stimulus
to the adoption of devices facilitating their production.

The Romans, it is generally conceded, did not make any
use of water-powered trip-hammers transmitting the
rotational movement of the wheel and its axle into the
vertical beat of a recumbent hammer by means of cogs.
China, unquestionably is the prime inventor. But the Plan
of St. Gall attests that at the beginning of the ninth century
such mechanisms were, even in the West, well known and
widely employed. This seems to vitiate the theory of its
westward diffusion by Marco Polo and suggests that the
knowledge of this invention came to Europe in the wake of
contact established with the Far East, in the fourth and
fifth centuries A.D. by the invasion of the Huns and other
Asiatic tribes, with whom the Visigoths were in close, and
often mortal, association over long periods of time.

FROM CHINA TO EUROPE DURING THE
MIGRATION PERIOD?

The display of water-powered trip-hammers on the Plan
of St. Gall gives added credence to such literary sources
as had been adduced by Bloch, Gille and Carus-Wilson[530]
in favor of the contention that hydraulic trip-hammers were
operated in eleventh- and twelfth-century Europe; as well
as the claim advanced by Uccelli and White[531] that the fulling
mills of Prato made use of hydraulic trip-hammers from
the beginning of this industry in A.D. 983.[532] An even
earlier reference (datable 883-904) to molinis vel pilis is to
be found in the Formulae Sangallenses miscellaneae.[533]

EUROPEAN SOURCES BEFORE MARCO POLO

A literary account of poetic beauty of water-driven
trip-hammers, written decades before Marco Polo's visit
to China (A.D. 1280), is to be found in a remarkable thirteenth-century
description of the waterworks of the monastery
of Clairvaux. There, after telling how the river Aube
had been deflected from its natural course, the writer
traces the water's path as it travels from workshop to
workshop, "launching itself at once upon the wheels of the
mill, and lashed into foam by their motion, it grinds the
meal under the weight of the millstones, and separates the
fine from the coarse by a sieve of fine tissue." Then, after
a brief excursion into the brewery, "where it fills the
boiler and is heated for brewing. . . not hesitating nor
refusing any who requires its aid," it follows the call of the
fullers, at whose workshop, close by the mill, "you may
see it causing to rise and fall alternately the heavy pestles,
that is to say, hammers or wooden foot-shaped blocks—for
that name seems to agree better with the treading-work, as
it were of the fullers—and so relieves them of the heaviest
part of their labor" (sed graves illos, sive pistillos, sive malleos
dicere mavis, vel certe pedes ligneos—nam hoc nomen saltuoso
fullonum negotio magis videtur congruere—alternatim elevans
atque deponens, gravi labore fullones absolvit. . .)[534]

TRIP-HAMMERS WITH VERTICAL PESTLES

There existed in the Middle Ages, as already mentioned,
yet another pounding mechanism making use of camming
action that cannot be overlooked in this context. It worked
with vertical pestles rather than with recumbent hammers.
Illustrations of these are found in the Mittelalterliche
Hausbuch of about 1480,[535] in several manuscripts of
Leonardo da Vinci[536] and in the manuscript attributed
to an anonymous Hussite engineer of around 1430 (fig.
456). Needham considers these vertical stamping mechanisms
"as characteristically European as the recumbent
tilt-hammer was Chinese."[537] This may be true, but there
is no historical assurance whatsoever that in Europe the
invention of the former preceded the adoption of the
latter[538] and any attempt to interpret the pilae of the Plan
of St. Gall, or the pistillos, sive malleos, vel certe pedes
ligneos of the thirteenth-century description of the water-powered
trip hammers of the Abbey of Clairvaux in the
light of this vertically operated pounding mechanism
would be straining the available historical evidence beyond
the limits of propriety. Amongst the vertical medieval
crushing devices listed by Needham, or anyone else
as far as I can see, there is not a single one with pestles
the shape of which could in any manner be compared
with that of a hammer (malleus) or a foot-shaped member
(vel certe pedes ligneos). A hammer, whether struck horizontally
or vertically, hits its object on impact, in a position
which places its longitudinal axis parallel to the surface
that receives its blow. It can accomplish this only with the

[ILLUSTRATION]

PLAN OF ST. GALL. MORTAR HOUSE. AUTHORS' INTERPRETATION

458.B

458.A

458.D

458.C

PLAN. TRANSVERSE SECTION, LONGITUDINAL SECTION; SOUTH ELEVATION

The Mortars of the Plan are here reconstructed as water-driven mechanisms, with their axle-trees oriented east and west and the presumptive
waterwheels to which these were geared oriented in the same direction, as are the waterwheels of the reconstructed Mill (above, fig. 448. A-E).

[ILLUSTRATION]

PLAN OF ST. GALL. AUTHORS' RECONSTRUCTION

458.E

458.F

WEST ELEVATION, NORTH ELEVATION

If a stream existed on the site and the land gradient permitted the development of waterpower, great efficiency could be achieved by this
alignment of the wheel races. For justification of water-powered mechanisms see above, p. 232, caption to fig. 448. In actual construction, we
believe such details would have been resolved by experienced craftsmen.

aid of a "foot-shaped" head piece lying at right angles to
its longitudinal axis. In the vertical crushing mechanism,
illustrated by the anonymous Hussite engineer (1472-78),
the Hausbuch Master (ca. 1480) and Leonardo da Vinci
(turn of the fifteenth to the sixteenth century), the pestles
are pointed, i.e., pencil-shaped, and could not by any
stretch of the imagination be interpreted as "hammer-" or
"foot-shaped" instruments. There is no doubt in my mind
that the pilae shown on the Plan of St. Gall must be interpreted
as recumbent hammers. They have the shape of
hammers, and the presence of a drum at the end, which
lies opposite the head of the hammer, as well as their
dimensions, allows for no other interpretation.[539]

RECONSTRUCTION OF PILAE ON THE
PLAN OF ST. GALL

Using as a model the trip-hammers of the iron forge of
Spechtshart's Flores Musicae (fig. 455), the trip-hammer of
the monastic smithy of Compludo (fig. 457), and the modern
example described by Meringer (fig. 453), we have reconstructed
the mortars of the Plan of St. Gall as water-driven
crushing hammers whose movement is controlled by the
cogs of a cylindrical drum mounted directly upon the axis
of a waterwheel (fig. 458).

DIETARY IMPORTANCE OF CRUSHED GRAIN IN
WESTERN EUROPE

The amount of crushed grain used daily in a medieval
monastery must have been considerable. A mixture of
barley and oats, made into a kind of porridge or "pap" by
the crushing action of the mortar was a chief item in the
diet of the people of Western Europe prior to the introduction
of the potato. The German word for this dish is mus,
and in the monastery of St. Gall the use of this term, as

[ILLUSTRATION]

459.A PLAN OF ST. GALL. DRYING KILN. AUTHORS' RECONSTRUCTION [1:192]

The shelter for the Drying Kiln is identical with those for the Mills and
Mortars of the Plan. This house could have been the simplest kind of structure,
perhaps even open-sided. Although the Drying Kiln would not develop
temperature so high as those needed for baking, some fire hazard would have
existed in a closed building; the Plan does not show either smoke exit or stack
port for this facility. We reiterate that these service structures of the Plan are
highly abstract; their purpose and siting were of foremost importance to the
Plan's makers; their constructional details, secondary.

Keller has pointed out,[540] was so prevalent that the monk
Kero renders the Latin word cibus, i.e., "food," with the
German word mus, and caenare, i.e., "to take one's supper,"
with the term abendmussen, i.e., "to sup on pap."

Crushed grain was also one of the primary ingredients in
the making of beer.[541]

V.15.4

THE DRYING KILN

The drying apparatus in the "house in which the grain is
parched" (locus ad torrendas annonas) need not detain us.
The egg-shaped symbol in the center is obviously a furnace
or oven enclosing a contained fire capable of producing
the slow and even heat needed for parching. Its form is a
hybrid between the ovoid corner fireplaces in the bedrooms
of the higher-ranking monastic officials, and the baking
ovens in the monastery's bake and brew houses.[542] The grid
of squares around this furnace is the frame of a drying rack.
Annonas should not be interpreted to refer exclusively to
grain parched in preparation for brewing. The Drying Kiln
was also the place where fruit from the abbey's orchards was
dried for use during the winter months as a substitute for
vegetables unavailable during this period.

[ILLUSTRATION]

459.B

POMPEII. CARBONIZED LOAF OF BREAD

The division of the loaf into equal-sized segments for easy distribution may have
had some relevance for Benedict's later instruction that the monks' ration of bread
be carefully and fairly weighed.

[ILLUSTRATION]

460. POMPEII. ROMAN ATRIUM HOUSE

[redrawn after Kahler, 1960, 163, fig. 80]

BAKING ESTABLISHMENT WITH LIVING QUARTERS

The layout combining living quarters with a commercial and industrial establishment,
shows Roman planing at its best. The forward part of the building is the
traditional Roman atrium house—descendant of a long lineage of Near Eastern and
Greco-Roman courtyard houses (cf. above, p. 6ff) which are as characteristically
Mediterranean as the aisled and bay-divided timber hall, from which guest and
service structures of the Plan descend, are Northern (cf. above, p. 23ff).

On the street front, to left and right of the entrance (1) are two three-room shops
(2, 3, 4; 5, 6, 7) unconnected with the interior. From the atrium (8) two stairs (9)
lead to the balcony giving access to an upper tier of rooms. To the left and right are
two cubicles (10, 11, 12, 13).

The rear part of the house, accessible through a fore room (14), which under normal
conditions would serve as tablinum, accommodates in an area of 8 × 10.2m (15)
four mills of the type shown in fig. 441, with paved walking strips for the donkeys.
Remaining rooms are: (16), a donkey stable with water trough; (17) a baking oven;
(18) a room for kneading and shaping dough; (19) a room for cooling bread; (20) a
bedroom for the mill slave, or kitchen (?).