The Threshing
Machine and its
Operation

Inside the Windmill Museum there is a beautiful
working scale model of a Threshing Machine built by Michael Fisher and donated by his
Mother.
In spite of the number of years we have had this
beautiful model threshing unit in the Windmill one wonders whether we can all explain how a full size live
threshing machine worked or even the reason for such an outfit in the first
place.
Why did we need such a
ponderous, heavy machine? This was one of the first daily chores in agriculture to be mechanised and its purpose
was to separate the grain from the straw as cereal plants, in sheaves, were fed into it. Before such
mechanisation was available the job of beating out the grain from the straw was carried out by hand, wielding a
heavy flail, beating at the straw on the barn floor.
On the model the steam
traction engine is to be seen. This drives the belt which powers the threshing machine. It was fuelled with
sacks of coke, started and helped with small coals. In later years diesel tractors took the place of steam
traction. Travelling was faster, setting up was easier, and there was no need to wait until a water boiler was
hot enough to use on full working pressure.
The friction belt was
set to drive the main shaft of the threshing drum set high up inside the machine. Sheaves of grain, maybe oats,
wheat, barley or rye are fed sideways into the drum, generally off a travelling canvas feeder. The strings on
the sheaves are cut to allow the straw to be fed to the drum evenly and without
overloading.
The grain now fell
into chutes as it was separated. These can be seen under the thresher end nearest to the engine by the driving
belt. The two left hand chutes collected the prime grain, the next two held the lesser grains and tail corn, and
the farthest chutes filled up very slowly with all the dust, weed seeds and rubbish.
On the side of the
thresher on the left there was a chute divided into two outlets with a lid to shut one whilst the other was
filling. This was the chaff-collecting box. Chaff was used as apart of a working horse’s rations and was also
used as pig bedding and chick litter. When horses were no longer available to make use of the chaff it was blown
among the straw which was travelling on reciprocating arms to feed it to the baler at the end of the whole
operation. The baler used an arm with a big square head to
press the straw into its feeding chamber. As this arm rose up to collect more straw the baler ram compressed the
straw left by the feeding head. As the ram drew back to reload, the head would bring down more straw; The grain
was raised in sacks via the sack hoist to the top or “Grain Floor” where it could be gravity fed to the rest of
the mill. Here it was tipped into a grain bin which was set into the floor and which could hold about four
sackfulls of grain. It passed down a wooden chute into a “stone hopper” above the stones and via an adjustable
gate into an inclined “shoe” which dropped it directly into the eye of the revolving
millstone.
The shoe was suspended
at the upper end by chains and its level adjusted by a crook string at the lower end. The shoe was inclined but
the grain would not flow unless shaken. This was achieved by the contact of a wooden “rap” fixed to one lip of
the shoe, with the corners of the revolving square-cut driving shaft (quant). The faster the stones turned, the
more the shoe was shaken thus allowing a greater flow of grain onto the stones.
The miller, working
on the meal floor below was warned that the stone hopper was nearly empty by a simple, yet ingenious device, a
bell attached to a leather strap fixed to the inside of the hopper could be brought into contact with the quant.
The middle of the strap, depressed by the weight of the grain in the hopper was released when the hopper
emptied, dragging the bell against the revolving quant, thus emitting a noise something like an alarm
clock.
The grain fed into the
stones was caught in the furrows and ground as it passed outwards, the resulting wheat-meal being contained
between the stones and their casing, the “stone-vat”. It then fell down through the metal spout to the control
floor where it was collected in sacks.
This product was pure
wholemeal flour which could be used to make rich brown bread with all the nourishment of the whole grain in it.
However in the latter years of milling, the public began to prefer white bread, which meant the wheat-meal had
to undergo a further process. It was passed through a flour dressing machine, a cloth-covered “bolter” in the
early days which was later superseded by a “wire machine” which effectively sieved the flour into three grades
and removed the bran which was then used principally for animal fodder.
The bale would be
wire-tied after threading the wire through a square steel “needle” which separated the bales. As stronger fibre
twines became available, bales became tied with these strings instead. The bales were made lighter and there
were no more snapped off short lengths of wire being eaten accidentally by cattle as they fed. It could often
prove deadly.
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