Stamp mill

The main components for water-powered stamp mills – water wheels, cams, and hammers – were known in the Hellenistic era in the Eastern Mediterranean region.

[2] A passage in the Natural History of the Roman scholar Pliny (NH 18.23) indicates that water-driven pestles had become fairly widespread in Italy by the first century AD: "The greater part of Italy uses an unshod pestle and also wheels which water turns as it flows past, and a trip-hammer [mola]".

[2] Apart from agricultural processing, archaeological evidence also strongly suggests the existence of trip hammers in Roman metal working.

[2] The widest application of stamp mills, however, seems to have occurred in Roman mining, where ore from deep veins was first crushed into small pieces for further processing.

[3] Here, the regularity and spacing of large indentations on stone anvils indicate the use of cam-operated ore stamps, much like the devices of later medieval mining.

[3][4] 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,[3][4][5] where the datable examples are from the 1st and 2nd century AD.

[10] 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.

[13] 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.

(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.)

[clarification needed] Stamp mills were used in early paper making for preparing the paper-stuff (pulp), before the invention of the Hollander beater, and might have derived from those used in fulling wool.