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).
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]
