Outwood Mill Construction
Outwood Mill is what is known as a Post Mill
the whole body of the mill, complete with its sails and machinery is balanced on a huge central post, on which the whole structure can be turned to face the wind – for no windmill will work unless it faces the incoming breeze, and the wind in this country is so fickle in the direction from which it comes that any windmill must be turned frequently.
The post is formed from a great baulk of oak, which, legend has it, was brought from Crabbet Park, near Crawley, some seven miles away. It would have been brought on a cart drawn by oxen, shaped by hand using simple tools and raised with ropes and levers to its present upright position, supported by four diagonal quarter bars and two crosstrees, which in turn rest on four brick piers.
The “Post” which identifies Outwood Mill as a Post Mill.
The whole supporting structure of the mill can be seen today within the brick roundhouse, which was itself a much later addition, built not only to protect the framing, but also to provide a convenient storehouse for grain and for the ground meal.
Thomas Budgen would have built up the body of the mill on the top of the upright post, hauling each timber into position with rope tackle, using techniques which were no doubt borrowed from those of sailing ships.
The complete body, or buck, weighs some 25 tons, and the mill stands around 39 ft high.
To turn her into the wind one must first raise the steps at the rear of the mill with a lever, the talthur, and then push the mill round with the tailpole, which projects from the rear of the buck. The whole mill is so beautifully balanced that it is possible for one person to turn her to bring the sails round into the wind. When into the wind, the steps can be lowered to act as an anchor, and to help stabilise the mill. After this has been done, then it’s a matter of climbing the steep ladder to enter the buck.
The lowest floor of the mill, known as the spout floor or meal floor is where the ground wholemeal flour descends through the spouts from the millstones above. Located dead centre of this floor is the upper part of the stout oaken post, protruding through the floor from below.
Overhead, across the top of the post, is the crowntree beam, another huge baulk of oak on which the whole mill is balanced and supported, and which turns on the top of the post when the mill is rotated.
Above your head you can also see the two pairs of governors, or “tenterers” to give them their correct name, which whirl round when the mill is operating, the balls flying out on their arms through centrifugal force and rising and falling with variations in the speed of the wind.
The Tenterers which control the “nip” (gap between the stones) in Outwood Mill
These balls are connected by a series of levers to the bridge tree, which supports the upper, or runner millstone, and adjusts the gap between it and the stationary lower or bedstone. As the speed of the wind increases, and the sails turn faster, the governor will bring the runner stone closer to the bedstone. Similarly, when the wind drops, the runner stone is raised again. This keeps the quality of the flour constant, in spite of the variations in the wind speed.
Climbing the ladder takes visitors to the next floor of the mill, known as the stone floor, for most of the floor area is taken up by the two pairs of millstones in their octagonal wooden casings, known as vats. But the area is dominated by the mighty eight-foot diameter brakewheel, mounted high at the front of the mill, which is in turn mounted on the huge oak windshaft, which carries the sails.
The brakewheel takes its name from the wooden brake which runs round its rim, and is used to stop the mill. This wheel also carries around its face 108 wooden cogs, each one separately mortised into the rim. These in turn engage with the small iron gear known as the wallower, which turns the upper or runner millstone.
The windshaft, some 13 feet long, is inclined at a shallow angle. Towards its rear end, another gearwheel, the tailwheel, is mounted. This wheel has arms of cast iron, bolted to a rim, again of oak, which is fitted with beechwood cogs. Recently, about a dozen of these were damaged by hitting a beam which had become displaced. When the damaged cogs were removed, on the tenon of one was written `G Medhurst 1872′, and on another ‘re-cogged October 1872’. George Medhurst was a well-known Sussex millwright, and it is a tribute to his workmanship that his cogs have lasted over 125 years – and indeed most of them are still going strong today!
The “Sweeps” or sails of Outwood Mill showing the Cast Iron cap.
About half a mile south of Outwood Post Mill on the road to Smallfields there is a turning to the left and this is called “Cogmans Lane” – perhaps this is where a millwright lived at somepoint during history.
The tailwheel in turn drives the all-wooden wallower which turns the runner of the second pair of millstones. Each stone is about 4 ft in diameter, and weighs around three-quarters of a ton. Mounted above each pair of stones is a small hopper, which keeps the stones supplied with grain when the mill is working.
Climbing the small flight of steps behind the tailwheel, brings visitors to the very top of the mill, the small platform known as the bin floor. Here are located the large grain bins which feed the grain under gravity to the millstones below.
The sacks of corn are raised to this platform by the sack hoist, controlled by the cord which passes overhead. This cord pulls a friction wheel into contact with the rim of the tailwheel, winding up another cord, which unwinds from a second drum and in turn raises the sack on the end of its hoisting chain. This system is most ingenious, and is only one of the unusual features of this famous old mill. If you look out of the window at the rear of the mill, at a view which has changed little in the three hundred and thirty-odd years since the mill was built.
Returning to the outside of the mill, you can see its four big sails, known as “sweeps” in the south of England. These are of a type known as spring sails, with shutters held closed when the mill is in use by the four large bow springs, so that wind pressure can open them in any sudden gust, thus preventing the mill running away out of control in a gale.
Outwood Mill was built in 1665, and the shuttered sail was not patented until nearly a century and a half later – by the Scottish Millwright, Andrew Meikle – so it is obvious that they were added later.
Outwood Mills first sails were what is known as common sails – consisting of sailcloth spread over a wooden frame. Nor was that the only change which was made during the life of the mill; it was another famous engineer and millwright, John Smeaton, who is generally credited with the introduction of cast iron into mills, in the early part of the eighteenth century. Thus you can see that many parts of the mill have been altered or replaced by the generations of millers who have needed to keep her running in order to maintain their livelihood.
One of the most prominent iron parts of the mill is the poll end or canister, which is fitted to the front of the wooden windshaft to carry the stocks – the two long timbers onto which the whips which form the backbones of the sails are bolted. The poll end also provides the neck, which supports the front of the windshaft, turning on an open brass bearing, kept well lubricated with tallow or grease.
To set the mill to work, the miller will note the direction from which the wind is coming, by looking at the little metal flag on the top of the mill, and turn her into it in the way previously described. Each of the sails is then brought down to the bottom in turn by releasing the brake, and the shutters are closed by operating the lever at the tip of the sail, one sail at a time, while controlling the mill by the brake rope which runs out through the window of the lower floor of the mill body.
If the bins are empty, the miller will go down into the roundhouse and hitch a sack of corn onto the hoisting chain. He then climbs up into the mill and pulls the hoist control cord. The sack is hoisted into the mill by the wind, onto the meal floor.
Now the miller must unhook the sack from this hoist on the meal floor and drag the sack to the far right corner of the Mill and attach it to the second sack hoist which will then hoist the sack to the Bin floor. Once on the bin floor the grain can be tipped into one of the bins, ready to fall by gravity into the stone hopper from where it can be fed into the millstones to be ground into flour.
The brake lever in Outwood Post Mill.
The miller will then stop the mill again with the brake, while he engages the wallower which drives the millstones. When the brake is now released, the heavy millstones will start to turn, and the damsel, the square part of the stone spindle, will shake the shoe which feeds the grain into the eye, the hole in the centre of the top, or runner stone. The runner stone turns above the stationary bedstone, and the grain is ground into flour between the faces of the two stones, moving outwards until it falls into the vat or casing, from which it finds its way down the spout to the floor below.
The flat surface of each millstone is cut, or dressed, with a series of fine lines, and it is these faces which in fact do the actual grinding of the grain. The pattern of larger grooves cut on the faces of the stones serves two purposes; to help the flour travel towards the edge of the stone, and to allow a current of air to flow between the stones, keeping the flour cool as it is ground. Nevertheless, the miller, as he feels the quality of flour coming from the spout, will still find that it comes out quite warm.
The miller was able to “fine tune” the stones as he was milling through adjusting the bridge trees up or down using a large wing nut attached to the longer arm of the bridge tree alongside the chutes on the meal floor. This would also adjust the adjuster on the tenterers (regulators) and allow a really fine level of control over the consistency of flour coming out of the stones.
The meal as it comes from the stones is wholemeal, containing 100% of the wheat berry, bran, wheatmeal, and above all the precious germ, now known as an important source of vitamin B. If a whiter flour is required, some or all of the bran may be removed by feeding the flour through a dresser, or bolter, a type of rotary sieve which separates the flour from the bran by passing it through a wire mesh or a silk cloth.
Outwood mill was at one time fitted with a bolter at the tail, or back of the mill, no doubt to satisfy the demand for white flour which grew up in the 18th century. That machine has long since been removed, although a similar one can now be seen in the roundhouse below.