Western food is traditionally based on the consumption of cereals, and in particular of different kinds of wheat, one of them being buckwheat, appreciated by Breton crews, which would have anti-scorbutic properties.
On land, as this was an indispensable product, the control of cereals, like that of salt, was a privilege (for which the King paid), and the intermediary of the owners and operators of grain mills, obligatory points of passage between the producers, who supplied the grain, and the users of the flour.
Flour is hygroscopic and attracts parasitic insects, a long conservation of cereals on board, before vacuum packaging was invented, may be preferable in the form of grains, rather than flour in barrels, a commodity that we commonly see in the supply inventories of this period.
In this case, the grain would have to be ground every day. For a ship of 100 people, the quantity to be processed is of the order of a 50 kg bag of grain per day, the grinding of which is a significant chore.
The hand-held grinding wheel
Small or medium quantities of wheat can be processed by hand by crushing between two small stone millstones of about 60 cms in diameter and 10 / 15 cm thick, each weighing a few dozen kilos (depending on the density of the stone).
The device includes:
- a stationary grinding wheel with a slightly convex, ridged friction surface to help the flour flow from the center where it is introduced to the outside. This is fixed to the base of the flour container. A small hole is drilled in the center of the receptacle to allow the rotation axis to pass through, sealed by a wooden “boitard” which prevents the flour from flowing around this axis.
- a running or rotating grinding wheel, encircled with steel, whose friction surface is slightly convex. It has a handle on the upper periphery to directly control its rotation. But the drive of the rotating wheel is generally linked to the essential centering axis common to both wheels, the rotation of the upper wheel being controlled by the “annulus“, an iron connecting piece fixed on this axis, which is housed in two notches dug in the stone on the lower face of the rotating wheel.
- The axis of the rotating wheel must not only allow the passage of the axis, but also the introduction of the grain, coming from a hopper, introduced by a “distribution trough” in the “oeillard”, circular iron piece lining the large recess of the rotating wheel. The trough undergoes jolts related to the rotation of the grinding wheels to distribute the grain in the “oeillard”.
In the next article, you will find the description of the windmill embarked in the De Langle’ ship.