|
The Millstones
A
pair of millstones, or a stand (also
called a run) of millstones consists of a
bedstone (stationary) at the bottom, and
runner stone (rotating) on top. The stones
are dressed to produce a geometrical
pattern of lands and furrows which crack and
grind the grain. As the grain progresses
outward from the eye, it is ground successively
finer, and emerges at the periphery at the
desired fineness. The stones never actually
come in contact, but are separated by a very
small spacing.
The dress of the stones is extremely
important in the grinding process. Different
dresses are required depending on the rotation
of the stones (corn stone turns counter
clockwise, one wheat stone turns clockwise, the
other turns counter clockwise when viewed from
above) and whether they are used for grinding
corn or wheat. In this mill, the milling season
ran from November 1st through May,
and during this period the stones would
typically be dressed twice. This was a very
long and laborious process often taking a week
and a half to complete (with help from Mr.
Collins’ sons after school).
The millstones at Anselma are of two types,
French buhr stones, or locally quarried solid
stones. The French buhr stones are made up of
many segments (as many as 30) bound together by
steel hoops and by a thick backing of plaster of
Paris. These stones were quarried in a specific
region of France east of Paris, and were
imported. The solid granite stones were
quarried in this country, and in the case of
this mill, from Tucker Hill, Virginia. The
French burr stones were used for grinding wheat,
and the solid granite stone was used for corn.
At
the center of the bed stone is a bearing for the
spindle which comes up from below to support and
turn the runner stone. The driver is an
oblong, hand wrought piece of iron which fits
over the spindle and rotates with the spindle.
The ends of the driver fit into recesses in the
runner stone to rotate the stone.
The rynd is a curved piece of iron
cemented into the runner stone. At the center
is a pivot point called the cockeye which
fits onto the top of the spindle called the
cockhead. The entire weight of the runner
stone is supported by the rynd on the spindle
The runner stone is perfectly balanced on the
cockeye. The socket of the damsel fits over the
top of the rynd so that it rotates as the stone
rotates.
The stone crane is used to lift the
runner off for maintenance and dressing. It
consists of a jack screw and two bales
which are attached to holes on either side of
the runner stone by steel pins. When the stone
is raised it can be inverted on the pins to turn
the underside up for dressing. One stone crane
serves both wheat stones, and the other is used
for the corn stone.
Runner Stone
  
Eye
Recess for Driver
Cockeye
 
Rynd
Bed Stone
Cockhead
Driver
Bearing
   
Spindle
|
