Pitstone Windmill – A History

Present-day view of the Pitstone Windmill

Pitstone Mill – Its History and Restoration

Account and drawings by David Wray 1976
Photographs by John Mullet and Stanley Freese
Copyright, Pitstone Windmill Committee

It may be asked why bother to undertake the considerable amount of work involved in restoring an old piece of machinery that even when completed will never be of practical use. A few years ago this view would have been widely held. But recently many more people have become aware of the need to protect the com­paratively few remaining traces of the old, more leisurely way of life, that, although hard, provided more personal satisfaction, through individual effort and responsi­bility than does the impersonal and regimented way of life that has become the norm for millions of people today.

Even as late as a hundred years ago many small rural communities were isolated and self contained entities affected but rarely by influences from the outside world. All food was locally produced and each little group had its quota of craftsmen who were in effect maintained by the community in return for their work in supplying essential services and goods. The whole group were interdependent upon one another thus engendering a spirit of mutual respect and individual responsibility. Weaver, thatcher, carpenter, wheelwright, miller, blacksmith, saddler, labourer, farmer and forester were all vital spokes in the constantly revolving wheel of rural life.

The local mill, be it wind or water driven was one of these ‘essential services’ providing as it did the means of converting grain into flour for breadmaking and many different kinds of meal for animal fodder. But the miller was helpless without the aid of carpenters, wheelwrights, sawyers and smiths who could build his mill in the first place and these craftsmen were in turn dependent on the foresters and wood men who grew the trees which provided the raw materials-including the charcoal with which iron could be smelted and worked. This interdependence remained unbroken until the gradual industrialization of the country that began to creep in during the latter part of the eighteenth century, eventually ousted the village craftsmen and replaced their products with, usually, inferior, mass produced, cheap, soul-less articles.

The tradition of personal responsibility and pride in craftsmanship led to the production of such masterpieces of folk crafts as the old farm wagons and carts, lace and strawplait and perhaps most striking of all, if only because of its size and complexity, the windmill.

Is there not just cause to venerate the man or small group of men who could conceive, design and build one of these extraordinary structures? They had no draw­ings and would have been incapable of reading them if they had. Their only guide was the inherited craft knowledge of centuries and a high degree of what has been called ‘manual literacy’. They went to the woods, selected suitable trees, probably felled them themselves, transported them to a sawpit on timber carriages they had made themselves, where they proceeded to saw out by hand every beam, stud and plank that they would use. Even their hand tools were largely village made, and by our standards primitive and restricted in variety. Yet in spite of all these difficulties and the lack of what today would be regarded as essential facilities, they produced well designed and proportioned structures that did what was expected of them and did it well.

Those who have devoted many hours of work to the restoration of Pitstone Windmill counted it a privilege to follow in the steps of these master craftsmen of past centuries and to have made some effort to preserve a tangible expression of their skill and ingenuity.

History of Pitstone Mill

No one can say with certainty when this mill was built. Documentary records for the ‘Windmill at Ivinghoe’ in the Bucks County Museum for the years 1624 to 1628 refer to tenants who ‘had’ the Mill at this time. They also contain accounts of payments made to carpenters working on the structure. As this work took some time and included ‘a new gable’ it can be inferred that a fairly old mill was being dealt with.

Three dates occur on the mill itself. The oldest 1627 is carved on a lower side girt and is obviously genuine. This is the earliest positive date connected with an existing mill, pre-dating the post mill at Bourn in Cambridgeshire by nine years.

The second date is 1749 and may, perhaps, refer to a rebuilding of the mill in which old, sound timbers were re-used. The last date – 1868 – was scratched with a carpenter’s knife on a badly decayed piece of elm timber that supported the wallower shaft. This timber, unfortunately, had to be replaced during restoration. It is certain that much of the machinery was replaced during the nineteenth century.

The enclosure of the open fields came late to the parish and the large open field in which the mill stands was still farmed in the strip system until 1854. A record of owners and occupiers and a map of the village was made in 1840 in connection with tithes. A road is shown crossing the field from roughly north-east to south­west, passing close to the mill. Perhaps it was an early Icknield Way. Another road at right angles to this linked it with the water mill at Pitstone. Both mills were the property of the Grand Junction Canal Company and occupied by Benjamin Anstee.

A deed in the Bucks County Record Office shows that Francis Beesley bought both mills from the Canal Company in 1842. He worked them both himself. It also records that he sold the windmill in 1874 for four hundred pounds to Lord Brownlow who owned the Ashridge Estate. Lord Brownlow let the mill to the Hawkins family—for many years the tenants of the surrounding Pitstone Green Farm.

In 1895 a good deal of repair work was carried out and this is commemorated by an inscription on the exterior wall of the round house. But in 1902 a freak storm arose and before the mill could be turned to face the wind, it struck the mill from behind, blowing the sails forward. This unshipped the tail bearing of the windshaft which flew up into the roof-and the sails, revolving the wrong way, crashed into the wall of the round house, doing extensive damage.

After this, the mill never worked again commercially as the expense of refitting could not be justified economically. A photograph taken about 1903 shows the mill still virtually complete externally but with shattered sails and shreds of cloths blowing in the breeze.

From then on deterioration of the structure was rapid. Gradually all the smaller fittings disappeared, even to the brass neck bearing; boards were stripped from the sides and carried home for firewood, the remnants of the sails rotted and fell apart and even the great tail ladder disintegrated. The work of ‘the snappers up of unconsidered trifles’ was completed by the sun and wind and rain.

In the early 1920’s the Ashridge Estate was broken up and many sitting tenants bought their holdings. So, in 1924 the mill became the property of the Hawkins family. In 1937, dismayed by the parlous state of the old mill and his own financial inability to undertake repairs, the owner, Leonard Hawkins, offered the mill with suitable access across his land, to the National Trust in the expectation that they would be able to make the necessary repairs and at least preserve what was left of the old mill for the enjoyment of posterity. This unusually farsighted action has made the recent extensive restoration possible.

Immediately the National Trust undertook a first aid operation. Messrs. Bushell Bros. of Tring were called in to tidy up and strengthen the whole structure as necessary. So much damage had been done to one side of the mill that a complete new framework had to be made and applied to the outside of the remaining timbers before recladding could proceed. To facilitate the work and provide as much protection as possible the cladding was carried across existing doors and windows with the exception of a few small windows in the side walls. Access to the body was now confined to a trap door in the floor reached by ladder from inside the round house. Various heavy timbers were inserted to act as props to what remained of the machinery. Although the work was done well and thoroughly, much of the essential character of the mill had been lost and a pair of tiny mock sails did little to improve the appearance.

Derelict. The windmill in 1935. (Stanley Freese)

Nothing further was done to the mill for some twenty years. Obviously during such a period deterioration was bound to take place. Nails rusted and cladding began to fall away, the birds and vandals prosecuted their attacks with ever increasing determination and another course of repairs was obviously necessary. Stanley Freese, who has devoted much time to the study of windmills and is the author of Windmills and Millwrighting, noticed that one of the quarter bars was sinking into the decayed end of a cross tree and that there was danger of the mill collapsing sideways. He also observed that one of the dates carved on a timber was 1627 and not 1697 as previously thought. As this was the earliest date to be found in any English windmill and the mill was one of the only two remaining post mills in the county, Mr. Freese and a few others felt that steps must somehow be taken to preserve it in a more permanent and, if possible, more interesting form. At this stage all that could be done was to insert vertical posts in the round house supporting the body of the mill, fit four extra quarter bars to the main post, and steel tie rods to the existing quarter bars. Unfortunately, the National Trust were unable to devote further money to repair. Their contribution was the provision of the steelwork and of new timber from the Ashridge Estate.

The Work of Restoration

Apart from the renailing of loose boards where possible and similar minor repairs, nothing further was accomplished until 1963.

In 1963 the Pitstone Windmill Restoration Committee was formed. It came into being as a result of discussions among a number of local people. Here was this fascinating old structure, in some ways quite unique, in every way a monument to the skill and ingenuity of craftsmen of many years ago, being allowed to fall into decay and eventual oblivion simply through a shortage of money to save it. Could nothing be done? The National Trust were still regretfully unable to undertake the work and to employ one of the few remaining firms of millwrights would cost many thousands of pounds. The only possible method that seemed to have any hope of success was to carry out the work by voluntary effort. Even so, a considerable sum of money would be required for the purchase of materials. In the absence of a wealthy patron, the generosity of the public was the only alternative. Competent and willing people were available and ready to make the attempt. Surely the few hundred pounds that would be needed could be raised without too much difficulty.

When this idea was suggested to the Local Committee of the National Trust they agreed readily to the attempt being made and offered to give oak and larch from the Ashridge Estate.

Before embarking on a public appeal for funds a coherent plan of operations was made. This started with a detailed and thorough examination of the structure and the consultation of experts in timber utilization and protection and such allied subjects. Obviously, if the work was to be of lasting value, permanence and durability of material was a primary concern. So pressure creosoted timber and bronze nails were selected for all exterior work and all interior timber both old and new was to be treated with a combined fungicide and insecticide.

The work itself was to be divided into three phases. The first and most pressing need was the complete stabilization of the structure and the prevention of further deterioration. The second aim was to restore the exterior to its original appearance, including new sails, providing no undiscovered weakness came to light during the course of the work. The third and final phase was to be the restoration of the interior to its working appearance. Eventually, a fourth aim was added to the list as the intrinsic strength of the framework came to be appreciated. This was to make the mill grind corn again, of course under carefully controlled conditions.

The watchwords, therefore, were to be durability, authenticity and no paid labour!

The appeal was duly launched with immediate and encouraging results and the preliminary clearing of accumulated rubbish inside and outside the mill was started in the autumn of 1963. Access for the transport of heavy materials involved making a new road some 250 yards long.

Restoration in progress, Summer 1965 (Stanley Freese)

When the work of repair and restoration began it immediately became apparent that the mill was in far better condition than had been feared and that in many cases timbers that looked almost hopeless were sound and hard beneath half an inch of surface decay. No timber has been discarded unless it was decayed beyond repair and would have constituted a hazard to durability. Weak joints have been strengthened with iron plates and two completely new floors installed as these, and in some cases the joists that supported them, were in a dangerous state.

Authenticity of external appearance was comparatively easily achieved as an old photograph taken about 1903 was available. For interior detail the recollections of the previous owner, Leonard Hawkins, who helped work the mill as a boy, have been invaluable.

As only the heaviest machinery remained in the mill there have been many visits to check up on details and to obtain spares from other derelict mills. In one case at least, this was only accomplished with some danger to life and limb. But luckily no one has been injured during the six years the work has occupied-in spite of some quite hazardous operations on roof and sails and when handling the grinding stones, which weigh well over half a ton apiece.

Approximately £1,000 has been collected as a result of the appeal and through donations given by some of the hundreds of people who have visited the mill on Sundays while work has been in progress. Further valuable assistance has come from business concerns and individuals who have either supplied materials free or at a discount, or who have lent equipment. Thanks are due to the Principal of Aylesbury College of Further Education for permitting the carpentry students to make the sails. Cost of materials has been well within the amount collected and the surplus invested to bring in a small income which, with admission charges, should be sufficient to cover the annual cost of maintenance and the small repairs which will undoubtedly become necessary.

How the Mill Works

 Pitstone Mill is a post mill of early type. That is, it is not fitted with a fantail or the elaborate shuttered sails commonly seen in East Anglia but is luffed or turned to face the wind by means of the tail pole; the ‘common’ sails are covered with separate sail cloths which can be reefed and furled by hand according to the strength of the wind. A post mill is the earliest form of windmill construction and consists of a rectangular body, containing all the machinery, windshaft and sails, balanced on the head of a massive wooden post which, in turn, is supported by cross trees and quarter bars. This supporting underframing can be seen in the round house. It consists of two timbers set in the form of a cross, their ends resting on brick piers. From the central crossing rises the great mainpost, cut from a single tree some 17 feet long and 33 inches across at the base. The post is maintained in a vertical position by four quarter bars mortised into it half way up its length and into the ends of the cross trees. A gap of an inch or so is always left beneath the post where it straddles the cross trees so that the actual weight of post and superimposed body and contents is transmitted through the quarter bars to the outer ends of the cross trees which are thus in perpetual tension. The colossal weight involved would, if applied to the centre of the cross trees, rapidly cause bending and eventual fracture.

It is interesting to note that the whole mill, including the wooden trestle, appears to have been raised at least once and possibly twice. The old small piers made of two inch brick can be seen within the present brickwork, which also seems to have been built in two separate stages. The reason for this was to have longer sails to give increased power.

Only half the mainpost is visible from the round house as the upper part is within the body of the mill. The heavy horizontal timbers, to be seen just above the heads of the quarter bars are called the main sheers and are the principal framing timbers of the lower floor of the body. These, together with two short transverse timbers also form a ‘steady’ bearing round the post-no weight comes on the post at this point-the bearing simply serves to prevent the body toppling over. Between the rear ends of the main sheers can be seen the forward end of the tail pole which is simply a huge lever by which the mill can be luffed into the wind. When this became necessary the foot of the ladder was lifted clear of the ground by means of a chain and lever, called a talthur, attached to the pole.

At the top of the ladder is a pair of large double doors opening into the first floor of the mill – meal or spout floor, so named because on this floor are the spouts which deliver the ground meal into bins or bags. Also on this floor can be seen the tentering gear, the underdrive to the stones and the upper part of the main post. Above this again is the stone floor and the heavier machinery.

The Windshaft

The most prominent feature on this floor is the heavy wooden windshaft. The front end of the windshaft carries the cast iron ‘canister’ through which pass the wooden stocks that carry the sails. Immediately behind the canister is the neck bearing and behind this again the brake wheel, so called on account of the lever-operated wooden band brake which encircles it. Also on the windshaft is a rough wooden pulley which drives a sack hoist through a slack chain clutch. When this chain is tightened by means of a rope and lever the sack bollard is set in motion and sacks of grain can be hauled up from the round house through the ‘clapper’ holes in the floors. After the passage of each sack these trap doors immediately fall back into place thus eliminating an obvious source of danger and, perhaps more importantly, allowing the sack to rest on the closed trap when the appropriate floor has been reached.

 

The Sack Hoist – On pulling the rope A, the lever B raises the beam C thus tightening the chain connecting the windshaft D and the sac hoist bollard E. The sack hoist chain F is stapled to the bollard and passes through the sheave chock fixed to the roof and so through the clappers (or trap doors) in the stone floor and meal floor to the round house. the operating rope A passes through the stone floor and ends in a stirrup on the meal floor

 

The more or less horizontal rotation of the windshaft is transmitted through the brake wheel to an iron wheel called a wallower set on a vertical shaft which passes through the stone floor and carries at its lower end a spur gear. On either side of the wallower shaft are the two pairs of stones, each in a wooden case or vat. Above the stone cases are wooden stools supporting grain hoppers. The lower stone of each pair is stationary and only the upper one revolves. The actual drive to the stones can be seen on the meal floor. The runner stone is balanced on a short stout vertical shaft called the stone spindle, which carries a ‘stone nut’. This is a small gear wheel which meshes with the spur gear at the foot of the wallower shaft. The stone nuts can be wound out of mesh when it is desired to isolate one pair of stones.

The stone spindles rest in adjustable bearing boxes bolted to wooden bridge trees which are pivoted at one end and free to rise and fall at the other. Movement at this end is controlled by the steelyards. These are long iron bars which pass through pairs of iron loops, one fitted to the forward end of the bridge tree and the other suspended from the stone floor above. The shaft of the loop passing through the bridge tree is fitted with what is in effect a very large wing nut. This is used to adjust fineness of grinding. The tail end of the steelyards is connected to the collar of the governors which are set in a frame behind the main post. The governors are driven from a wooden pulley bolted under the spur gear on the wallower shaft. As the governors operate according to the fluctuating strength of the wind the steelyard collar on the governor shaft is continually sliding up and down, taking the tail ends of the steelyards with it. This rise and fall is transmitted through the bridge tree and stone spindle to the runner stone. The purpose of this rather involved action is to regulate the fineness of grinding to match the speed at which the sails are revolving. The passage of the grain between the grooved faces of the stones creates enormous friction which has considerable braking power if not relieved. Consequently if the wind is light the stones are kept further apart and grinding is slow. If the wind increases in force and the sails begin to revolve faster the action of the governors is to lower the runner stone and create more friction thus preventing the sails from ‘running away’, at the same time maintaining the fineness of grinding. Should the wind velocity increase drastically the sail area might have to he reduced by reefing.

From the central hole or ‘eye’ of the stones the grain passes slowly towards the periphery, all the time being crushed into finer and finer particles by the scissor action of the grooves cut in the opposing faces of the stones. These furrows may need renewing as frequently as every two to four weeks depending on the amount of work done, When it emerges from between the stones the meal falls into the cavity between stones and stone cases-and is swept round by the revolving runner stone and eventually falls into the mouth of a wooden trunk which leads it to the bins on the floor beneath. From these bins it is bagged up, weighed and set aside to await collection.

If the meal is for white breadmaking the bags of meal are once more hoisted to the top of the mill and passed through the flour dresser in the tail of the stone floor. This machine separates out the flour, middlings and bran by means of revolving brushes working within a cylindrical drum of wire mesh and discharges them through canvas chutes directly into bags. These chutes can be seen on the meal floor hanging from the floor above, immediately inside the main door.

  • A – Hopper supported by
  • B – Stool fixed to the … 
  • C – Stone case.
  • D – Slipper beneath the hopper is agitated by
  • E – Damsel.
  • F – Mill stones.
  • G – Wooden trunk communicating with the space between C & F.
  • H – Meal bin.
  • I. – Cord adjusting angle of slipper.

Grain is placed in the hopper. It descends into the slipper, and is shaken steadily into the eye of the upper stone. From here it passes outward between the stones finally emerging as meal. It then falls down the trunk into the bin beneath.

  • A – Upper revolving mill stone.
  • B – Lower fixed stone.
  • C – Great spur gear meshing with
  • D – Stone nuts.
  • E – Bridging box forming step bearing for spindle M.
  • F – Bridge tree.
  • G – Steelyard loops.
  • H – Mechanism for disengaging stone nuts from great spur gear.
  • I – Crown tree.
  • J – Intermediate pulley.
  • K – Governors.
  • L – Steelyards.
  • M – Spindle.
  • N – Driving pulley bolted beneath great spur gear.

The action whereby the gap between the millstones is adjusted according to variations in wind force is described in the text.

 The Grinding Process

 So far only the machinery itself has been described, with little reference to the passage of the grain and flour. When the corn is delivered to the mill for grinding it is unloaded from cart or wagon into the round house where it is stored until required. Eventually it is raised to the stone floor by means of the sack hoist where it is tipped by hand into the hoppers on the stools above the stones. From these it falls into the ‘slippers’ which are shallow troughs, vibrated by contact with the ‘damsel’. This is an iron bar furnished with three or four lobes or ridges and revolving with the runner stone. The side of the slipper is kept pressed against the lobes of the damsel by a piece of string attached to a springy lath. The ‘clack, clack, clack’ of slipper against damsel is said to have given this item its curious name. Like its reputed namesake, it makes more noise in the mill than anything else! Another cord regulates the slope of the slipper and, consequently, the rate of feed into the stones.

  • A – Hopper containing grain
  • B – Slipper
  • C – Rap of hard wood to take wear of damsel
  • D – Damsel
  • E – Wooden spring holding slipper against damsel
  • F – Cord conreolling angle of slipper
  • G – Upper mill stone
  • H – Bar leading into uppermill stone
  • I – Mace or Rhind

 

The Stones

The right hand pair of stones are made of Derbyshire millstone grit and are usually referred to as Peak stones. These are used for grist work-that is, relatively coarse meal for stock feeding. The left hand stones are those used mainly for milling wheat for flour and are constructed from a very hard stone quarried in Northern France. Their common name is ‘French Burr’. Owing to the nature of the stone (which looks rather like Gruyere cheese) it cannot be quarried in large pieces so that each stone has to be built up from a number of small sections. To give the necessary solidity the layer of stone is backed up with cement or plaster of Paris and iron hoops are placed round the edge to hold the whole mass together. Other types of stones were used but French Burrs and Peaks are those most commonly found.

The Upper Floor with the windshaft, wallower, stonecases and hoppers. (John Mullett) 

The Meal Floor showing the upper part of the main post and the bins to receive the meal from the grinding stone above. (John Mullett)

The Sails 

The sails consist of four open frames over which canvas cloths are spread. Each frame is bolted through its whip or backbone on to the stocks which pass through the canister.

The twist that is built into each frame is designed to make the best use of wind pressure and at the same time eliminate drag at the tips which are of course travelling at far greater speed than the heels of the sails.

The cloths are attached to iron rails at the heel of each sail and are spread by means of ropes attached to the cloth. Reefing consists of restricting the amount of sail spread to the wind, and to furl a sail it is rolled into a long bundle, the free end taken round the back of the sail and passed forward between the sail bars and tied off.

Fastenings

  • A – Cotter bolt. Extensively used before the introduction of standardised nuts and bolts.
  • B & C – Forms of strap bolt. Either may be found with cotters instead of nuts. The wodden pegs or dowels shown in B were all that held together the majority of timber framed buildings. Only in structures subject to violent stress were iron fastenings used.
  • D – Hand forged nail

Decorations

  • A – Bracket supporting the weather beam
  • B – Stopped chamfer at head and foot of wall studs
  • C – Carved moulding occuring on side girts and cross-trees
  • D – Turned moulding on main post at meal floor level
  • So much decoration is unusual and may be a further indication of early date.

Technical Info.

The following information concerning the working of the mill may be of interest:

  • Speed of Sails: 15 r.p.m 
  • Speed of Stones: 120 r.p.m. (under ideal conditions)
  • Brake Wheel: 88 teeth
  • Span of Sails from tip: 51ft.
  • Power generated by sails: Each pair of stonesneeds at least 10 h.p. to drive them. Both pairs of stones would only be used at the same time in exceptional circumstances.
  • Life of Stones: 10-20 years 
  • Size of Stones: 4ft diameter x 12in deep when new.

Postscript

In 1970 Pitstone Mill again ground corn after 68 years of idleness.

In the same year the mill was formally declared open by Viscountess Davidson and the restoration gained one of the ‘Countryside in 1970′ awards which were promoted by the Duke of Edinburgh’s ‘Countryside in 1970′ Conference.

Leonard Hawkins who gave the Mill to the National Trust in 1937 died in 1975 at the ripe old age of 94.

Stanley Freese died in 1972 and a plaque has been placed in the Mill commemorating his work.

In 1975 a further date was discovered on one of the upper side girts of the Mill. It is a small neatly carved inscription and reads: ‘Nov 29 1784′. Its significance can only be guessed at but in view of the care with which it has been executed, it may well record a minor rebuild or at least repair work.

 

 

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