's
De re metallica (1556) The main components for water-powered stamp mills –
water wheels,
cams, and hammers – were known in the
Hellenistic era in the
Eastern Mediterranean region.
Ancient cams are in evidence in early water-powered
automata from the third century BC. These trip-hammers were used for the pounding and hulling of
grain. Such mechanically deformed anvils have been found at numerous Roman silver and gold mining sites in
Western Europe, including at
Dolaucothi (
Wales), and on the
Iberian Peninsula, where the datable examples are from the 1st and 2nd century AD. At Dolaucothi, these stamp mills were hydraulic-driven and possibly also at other Roman mining sites, where the large scale use of the
hushing and ground sluicing technique meant that large amounts of water were directly available for powering the machines. Stamp mills were used by miners in
Samarkand as early as 973. They were used in medieval
Persia to crush mineral ores. By the 11th century, stamp mills were in widespread use throughout the
medieval Islamic world, from
Islamic Spain and North Africa in the west to
Central Asia in the east. Water-powered and mechanised trip hammers reappeared in medieval Europe by the 12th century. Their use was described in medieval written sources of
Styria (in modern-day Austria), one from 1135, and another from 1175. Both texts mentioned the use of vertical stamp mills for ore-crushing. Medieval French sources of the years 1116 and 1249 both record the use of mechanised
trip hammers used in the forging of
wrought iron. Medieval European trip hammers by the 15th century were most often in the shape of the vertical pestle stamp-mill. The well-known
Renaissance artist and inventor
Leonardo da Vinci often sketched trip hammers for use in forges and even file-cutting machinery, those of the vertical pestle stamp-mill type. The oldest depicted European illustration of a
martinet forge-hammer is perhaps in the
Historia de Gentibus Septentrionalibus of
Olaus Magnus, dated to 1565 AD. This woodcut image depicts three martinets, and a waterwheel working the wood and leather bellows of an osmund (
sv)
bloomery furnace. The recumbent trip hammer was first depicted in European artwork in an illustration by
Sandrart and
Zonca (dated 1621 AD). Water-powered stamp mills are illustrated in book 8 of
Georg Agricola's
De Re Metallica, published in 1556. The mills Agricola shows were largely wooden construction, excepting the use of
iron shoes on the end of each stamp. The
camshaft was set directly on the axle of the
waterwheel, and stamps were typically arranged in gangs of three, with each wheel driving one or two gangs.
19th century The first stamp mill in the U.S. was built in 1829 at the Capps mine near
Charlotte, North Carolina. They were common in
gold,
silver, and
copper mining regions of the US in the latter 19th and early 20th centuries, in operations where the ore was crushed as a prelude to extracting the metals. They were superseded in the second half of the 19th century in many applications by more efficient methods. However their simplicity meant that they were used in remote areas for ore processing well into the 20th century. (19th century advertisements for some mills highlighted that they could be broken down, packed in by mule in pieces, and assembled on site with only simple tools.) Stamp mills are still in use in Colombia by artisanal miners, powered by electric motors.
s are stamp mills that were developed in
Cornwall for use in
tin mining in around 1850. Cornish stamps were used to crush small lumps of ore into sand-like material. The stamp was constructed from heavy timber with an iron "head" at the bottom. It was lifted by cams on a rotating axle, and fell on the ore and water mixture, fed into a box beneath. The head normally weighed between 4 and 8
cwt (about 200 to 400 kg) each, and were usually arranged in sets of four, in timber frames. Small stamps were commonly powered by
water wheels and larger ones by steam engines.
Californian stamps were based on Cornish stamps and were used for the
Californian gold mines. In these stamps the cam is arranged to lift the stamp from the side, so that it causes the stamp to rotate. This evens the wear on the shoe at the foot of the stamp. They were more rapid in action and a single head could crush 1.5 tons of ore as opposed to the Cornish stamps which could only crush 1 ton. == Other stamping mills ==