Editing Millstone (section)

=== The Roman trapetum ===
The [[Hellenistic period|Hellenistic]] period also saw the appearance of the olive crusher, which the Romans called the ''trapetum''. Legend has it that it was invented by [[Aristaeus]], and excavations at Olynthus have revealed examples dating back to the 5th century BC.<ref name="Gille" />

The ''trapetum'' was precisely described by Cato the Elder, who gave us the technical names of all its parts. Excavations at Stabies, [[Pompeii]], the villa at [[Boscoreale]] and in [[Roman Africans|Roman Africa]] show that the system was widely used in ancient Rome and disappeared with it.

The ''trapetum'' consists of two plano-convex millstones (3, ''orbes''), standing vertically, supported by a horizontal axis rotating around a vertical pivot (1, ''columella''). This pivot rests on a short stone column (''milliarium'') at the center of a large hemispherical mortar (4). The lying millstone is a stone vat (4, ''mortarium'') whose walls follow the external profile of the two common millstones. The orbs can move in a circular motion inside the ''mortarium'', and are set in motion by the action of two wooden handles (2, ''modioli''). Wooden wedges (''orbiculi'') inserted between the ''milliarium'' and the ''columella'' are used to adjust the height of the orbs above the bottom of the vat. In this system, the olives are not crushed under the millstone, but between the millstone and the sides of the vat.<ref name="ista2" /> As in the previous model, a gap was maintained between the two millstones. The resistance offered by the fruit forces the stone half-spheres to turn slightly on their axis; the two movements combine and the pressure is exerted only moderately, without breaking the stones, which would give bad taste.<ref><sup>(fr)</sup> [http://www.mediterranees.net/civilisation/techniques/agriculture/olea.html Techniques dans l'antiquité gréco-romaine]</ref> The resultant pulp could then be subjected to the action of a press to collect the oil.