Posted on

Technical descriptions of English windmills



CAPEL, Shiremark Mill

Smock mill, base survives (main part burnt down 1972)


Farries (description written by Denis Sanders):

The mill is octagonal and mounted on a red brick base. The large size of this base is not obvious from the outside, as a mound of earth extending to within five feet of the top was thrown up to make a platform from which the original cloth sails could be set and reefed. On the east side is the main door, flanked by retaining walls for the mound. These formerly carried boards on top to complete the walkway round the base. The height of brickwork above the ground floor inside is 8ft 6in. The top of the mill base is 24 feet across and the thickness of the brick wall is 14in, increasing below. The brickwork was tarred outside and whitewashed inside.

 On the octagonal base rest the eight oak sills 10in by 6in, mortised together at the corners. These are important structural parts, serving to tie the various members together, and also to spread the weight of the whole construction evenly over the brickwork. Above them stand eight main corner or cant posts mortised into the sill joints and secured in each case with two oak pins. These posts are of oak, 9in square and 21 ft long, sloping inwards to give a taper to the tower. The tops of the posts are mortised into a circular built-up wooden curb of 9in square section and 14 ft diameter, which is in eight segments with scarf joints, having vertical meeting faces, between the posts. Two sets of eight horizontal members, called ledges or transoms, are fixed between the posts at suitable heights to carry floorbeams and joists as required; the transoms are of oak 6in square. This constitutes the main framework of the tower. In each of the 24 resulting spaces is fixed intermediate framing consisting of a central vertical member 5in square and two diagonal struts 5in by 3½ in. On the north and south sides of the first floor, however, pairs of verticals form doorways; doors on opposite sides were provided in order to ensure safe access whatever the position of the sweeps. A portable ladder was used to reach these doors.

 The upper surface of the curb is shod with iron, forming a trackway on which the cap rests and is free to turn. Two timbers – the sheers, 12in square, 16ft long, and set about 10 ft apart – form the main members of the cap frame, running fore and aft and carrying three heavy cross timbers: the breast beam in front, the spindle beam at centre and tail beam towards the rear. These extend beyond the sheers to carry the side sills, from which spring nine pairs of coupled rafters forming the roof. The rafters are connected by double wooden collars and pegged together at the top; there is no ridge piece. Pairs of vertical timbers fixed at the front and rear of the cap complete the framing. The cap is 17 ft long, 14ft wide and 10ft high above the curb, and the height from ground floor to roof ridge is 40 feet. Although the cap is of ungainly appearance from most angles, owing mainly to the large overhang at the rear, the head-on view is surprisingly clean and neat. The wooden studs throughout cap and tower, comprising about 160 members of various sizes, are not structural but serve to stiffen and support the lapped weatherboarding. The common joists on all floors are 4in square.

 Curbs are known as “live” or “dead”, according to whether the cap turns on rollers or sliding blocks; at Shiremark is a curious combination of the two. There are three iron rollers 8in in diameter by 4in wide, set on 14in centres, all carried in a single iron bracket bolted to the underside of the breast beam below the windshaft, but the rest of the curb has only sliding contacts, four of them bearing under the points where the sheers cross the curb, two more under the tail beam at the rear, and a further pair fitted singly at either end of the spindle beam, all these points being iron-shod to take the wear.

 Rotation of the cap was effected by means of an endless chain hanging from the rear. This chain passes over a Y-wheel – the name derived from the wheel’s having a series of Y-shaped iron forks around its edge forming a crude vee-pulley – this is 3ft 8in diameter, iron-spoked and wood-rimmed, inside the cap on a sloping cross-shaft, and drives through reduction gearing an iron worm meshing with 91 wooden cogs of 6in pitch mortised into the outer edge of the curb. The four forward truck wheels are 14in in diameter, of wood iron-bound, and carried in large wooden brackets; and the other six are of iron, 11in in diameter.

 Interior arrangements in the mill body do not follow normal windmill practice, for the first floor is at two levels with a 4ft difference and a short connecting ladder. Two timbers 12in square, 23 feet long and 6ft 6in apart stand across the sills north to south and carry the joists of the first floor at lower level on the east side. These beams also form the base of the hurst frame – the heart of the mill – containing two pairs of underdriven millstones, gearing to drive them, and a system of levers to adjust the height of the upper millstones in relation to the lower ones, this operation being known as tentering. The floor joists at the higher level, on the west side, are framed off the upper parts of the hurst, while the top or dust floor joists are supported by a pair of 11in by 12in beams standing across the upper set of transoms, also north to south. All floor beams and hurst posts are of pine.

 The last set of sweeps fitted were double-shuttered patents, which turned anti-clockwise. They spanned 60 feet and were 6ft 10in wide, with seven bays of four shutters each and one inner bay of three only. All shutters, of wooden feather-edge boards, were 8½ in wide, those on the driving side 3ft 10in long, the leading ones 22in long; the inner three bays on the leading sides had no shutters but a fixed leading board in the Sussex manner. The middlings were 39ft long, 12in by 14in at the centre, tapering to 6in square at either end, and strengthened in the middle by pairs of timber clamps 8in by 5in and 10ft long. The sweeps, doors, windows and portable ladder were painted white; the cap and tower tarred black.

 The windshaft, with canister to carry the middlings, is a single iron casting about 16ft long overall, 12in in diameter at the neck journal, and 8½ in square a tthe brakewheel; it tapers to 6in diameter at the rear, with the tail journal about 4in in diameter. The shaft is inclined at approximately ten degrees, and is carried at the rear by a bearing on the tail beam, and at the neck by a large block of oak supported above the breast beam. To stop the block “creeping” forward, two iron rods with turnbuckles to tighten them are fixed to the top of it, and are anchored back to a tie beam standing across the sheers. To protect them from the weather, the bearing block and neck journal of the shaft are enclosed in a wooden box supported in front of the cap framework. Near the centre of the shaft is the brake wheel, a face gear of all-wooden clasp-arm type, 9ft in diameter, with two sets of arms 5in by 4in, and eight cants in two sets of four, one behind the other, arranged to break joint. The forward cants are 22in deep by 2in thick, the rear 20in deep by 4in thick. Faced on to the latter is the 8in by 2in rim in four unequal sections. Seventy-five wood cogs of 4½ in pitch and 3½ in face are mortised through the rims and cants and secured by nails through the shanks on the forward side. This wheel has been converted from a compass-arm type having two arms morticed through a wooden windshaft to form a four-spoked wheel; the outer ends of these arms remain in place. The mounting of the brakewheel on the windshaft presented a problem when the original wooden shaft was later replaced by the existing much thinner iron one. Two iron plates 19½ in square were keyed on the shaft 14in apart and, with four pieces of angle iron across the corners, formed a box on which the wheel could be wedged. Folding wedges were used, eight pairs being necessary. These were adjusted until the wheel ran true.

 The wooden brake lever, 10ft long, is pivoted from a vertical stub timber mortised into the right sheer about 14in ahead of the brakewheel. It controls a wooden brake consisting of six unequal segments 7½ in by 2½ in in section, jointed with pairs of iron butt-straps and bolts. A strong iron hook and chain connects the lower – dead end – to the right sheer, and the upper – live part is joined to the lever by an iron strap. Operation was from the ground by a rope which passed up over a pulley set above the lever, down to a second pulley on the lever itself, then up again to be secured finally to a beam.

 The upright shaft was driven from the brake wheel by the wallower, an iron wheel 3ft in diameter with 26 teeth; it is cast in halves for bolting together to facilitate installation. It no doubt replaced a wooden wheel which had given many years’ service. Fixed on the underside of the wallower is a built-up wooden friction ring 3 ft 4in in diameter, which drove the sack hoist described below. The wallower is maintained in position at the top of the upright shaft by means of four wooden brackets spiked on beneath it, and is set to run true by wooden packing and wedges between wheel and shaft. The shaft is made from a single piece of elm 21 feet long, and is 16-sided through most of its length, being 14in across near the top, increasing to 16in below, and having a section 19 in square at the lower end, on which is mounted the great spur gear. This is of all-wooden clasp-arm type 6ft 6in in diameter, with a single set of arms 8½ in by 3½ in on the underside, four cants 20in deep by 4in thick, rim 7½ in by 3in in four sections, and 70 wood cogs of 3¼ in pitch and 3½ in face. Wooden wedges and packing are used to secure the wheel to the upright shaft.

 The two pinions driven from the great spur wheel – the stone nuts – are of solid wood, 20in in diameter and 8in thick with wooden cogs morticed in and secured by iron pins driven through from the top into the shanks. They are bound with iron above and below the cogs, to prevent splitting, and wedged with wood on to the vertical iron spindles on top of which the upper or runner millstones are balanced. The nut for the burr stones has 20 cogs, and that for the peak stones eighteen. Thus the burr runner turned 10 times, and the peak runner turned almost eleven and a quarter times, for each revolution of the sails. Each nut could be disengaged from the great spur as required by removing three special cogs, and turning the spindle so that the gap was towards the main gear; an iron hook attached to a beam was then dropped into a staple on the rim of the stone nut to lock it in this safe position. This gearing is contained within the hurst frame below the stones, which accordingly were underdriven. The foot of each stone spindle is in a bearing carried near the centre of a wooden bridge tree, a horizontal beam 11in by 12 in deep and 6ft long, pivoted at one end. The other end of the bridge tree is carried by a lighter beam at right angles known as the bray, itself pivoted, with the free end connected to the steelyard, and iron rod directly controlled by a centrifugal ball governor, the purpose of which was to counteract irregularity of grinding caused by varying wind conditions. This is the system of levers referred to when describing the hurst. There were formerly two governors, each belt-driven from the spindle of the pair of stones which it controlled. However these have been missing for some years. They were of twin ball type, tall and slender.

 Both pairs of stones are on the hurst (upper level of the first floor), on opposite sides of the upright shaft. They are both 4ft in diameter, but of different kind. Those on the north side are Derbyshire peaks, grey in colour, hewn solid, and used for grinding oats and barley. The south stones are French burrs having a yellowish colour, hewn in pieces, cemented together and bound with iron strips, and used for grinding wheat. Two pairs of strong horizontal timbers are fixed between the upper cross beams of the hurst; on these the bedstones are laid and set level at the required height by wooden packing. Each bedstone has a hole in the centre, in which is fixed a bush forming the upper bearing for the stone spindle. To ensure that the spindle ran truly upright the lower bearing, set on the bridgetree, was arranged to be adjustable sideways in any direction. At Shiremark a very old method of doing this was in use until the end. The pot in which the spindle turned is formed on top of a rectangular block of metal, which sits loosely in a cut-way portion or housing on the upper surface of the bridgetree, and has two flanges which extend downwards on either side also. Wooden wedges driven between the sides of the housing and the block give control along the length of the bridgetree, and other wedges between the flanges and the sides of the bridgetree allow adjustment at right angles. This device is a typical example of the older style of millwrighting. The base of the wooden upright shaft was centred in the same way where it is supported on a large beam bolted up at right angles beneath the main beams of the first floor.

 The flour dresser is situated on what would normally be the second floor; at Shiremark the latter comprises only a small floor area on the east side. The bolter consists of an inclined wooden shaft supporting a wooden cylindrical frame on which was secured a stocking of woollen bolting cloth. The rotor, 5ft 6in long and 2ft in diameter, enclosed in a wooden casing, was driven by a belt from a pulley on a short horizontal wooden shaft 4in square supported by the dust floor beams. This shaft carried an iron spur pinion to mesh with an upturned wooden face gear on the upright shaft; the pinion could be raised out of gear as required by a wooden lever. The face gear is of simple construction, consisting of a disc 3ft 8in in diameter and 4in thick, made in halves diametrically. Two loose tongues fit in mortices in both halves, with wood pegs to secure them, and an iron dovetailed butt-strap is let in flush with the rim edge on either side and spiked in position. Fifty-nine wooden cogs are morticed directly into the top face. Four large wooden tapering brackets fixed on the shaft support this wheel, with wood packing to centre and secure it.

 The sack hoist, supported by a wooden frame standing across the main dust floor beams, was driven by friction from the wooden ring on the underside of the wallower. A 20in diameter by 8in thick solid wooden wheel mounted on the chain drum was raised into contact with the ring by a long wooden lever, controlled by a cord extending down to ground floor level. This cord operated through a multiplying gear slung from the curb. The chain was wound up on the drum and led over a pulley fixed above the series of double trapdoors in the floors, through which the sacks of grain passed on their upward journey. The hoist drum was on the north side, and the trapdoors in the north-east quarter of the mill.

 Hurst mounting of millstones in tower windmills is unusual (although common in watermills), but it is found in two or three much further north, including the notable Chesterton mill, Warwickshire. Shiremark seems to be the only example recorded south of the Thames, and in point of design below dust floor level can almost be considered as a “wind-driven watermill”. The hurst is placed somewhat off-centre on the west side, giving a greater floor area on the eastern side for working space, bagging, loading and so on. Both pairs of stones were in octagonal wooden cases, and the meal emerged through holes cut at an angle in the main east supporting beam. A large tapering wooden bin suspended from the dust floor ceiling on the south side fed the burr stones, with a long shoe. The mill was patched up latterly to run the peak stones only; these were fed by a sacking chute direct from the dust floor. The “wooden blacksmith” provided a new twin mortised bearing block for the fixed end of the bridge tree and gave some attention to its controlling bray, which was getting into a bad state. She then carried on for a few years more.

 In 1956 Mr George Stone {former miller} said that the mill drove well and was reliable, and the hurst layout was convenient for working, but that the increasing difficulty of winding was very trying. Asked about east wind working, he asked that this gave the steadiest running, a view expressed by windmillers elsewhere.

 The early method of wedge adjustment of footstep bearings in use here has been described. Curiously, at the top of the upright shaft the later method was in use. An inverted bridging box with adjusting screws is bolted below the spindle beam. An unusual but convenient arrangement, this was used also at Trumpets Hill mill and at Jolesfield, Sussex, probably all fitted by the same millwright.

 The winding gear in its final form, as described, is a modification of an earlier scheme using an 8ft diameter wheel set flat just inside the rear gable. At that time the gearing and the worm were probably all of wood. The present iron worm – “A fish out of water” – has a tremendous backlash and may have allowed the cap to kick badly in some conditions. The change of gear was made necessary by the fitting of patent sails, the striking mechanism for these extending to the main gable and thus fouling the large wheel. It seems likely that the convenience of the new sails was partly paid for by a set of winding gear less sweet than the old. It was extremely hard work towards the end to turn the cap, and due to curb trouble that the mill finally stopped work, as happened in so many other cases. A wind vane mounted over the rear gable could be seen by the operator as a guide when winding the mill; it was necessary to haul about a quarter of a mile of chain to turn her through 180 degrees, and the chain was grasped with sacking.

 Inside the main door, facing the Horsham-Dorking road, three brick steps on the left led to a heavy wooden ladder, at the top of which was the lower level of the stone floor. Here were the spouts; meal from the stones being delivered direct into sacks hung on the hurst, and the output from the dresser above discharged into various chutes as required. At some time there had been another dresser situated on the north side of the stone floor, driven from the face gear on the upright shaft. There was also a hand-operated malt mill to supply a few customers. Warning bells, for drawing attention to empty hoppers, were worked from the base of the upright shaft, which had four wood blocks nailed on to form a primitive cam. Wooden rockers, connected by cords to weighted levers, came into contact with these when the grain ran low, and rang the bells.

 In the south-west corner of the stone floor at higher level, by the window, was an office, with a fine view across the Sussex Weald. The lower halves of the two cant posts on the south-west quarter have been plated on their inside faces with pieces of pine 9in by 3in and pencilled on one of these is “P. HEWETT. DEC. 20. 1885.”

EWHURST, Hurtwood Common

Tower mill, standing today


The brakewheel here is wood, the brake wrought iron and the windshaft cast-iron (Farries).

LOWFIELD HEATH, post mill (now at Charlwood)


Farries: Enough remains, or was observed in 1955, to make a description of the mill’s machinery possible. The most vital structural timbers are still sound and of formidable girth; the crowntree is no less than 2ft square; the crosstrees and quarterbars are 1ft square each, and the beautifully rounded centre post tapers in the spout floor from 21in to 16in in diameter. Three iron rings at the top, each 2¾ in by 3/8 in, encompass the cross-tailed gudgeon. The crowntree straddles the mill at 7ft behind the breast beam and 13ft in front of the rear door, and since there were two pairs of stones, one before and one behind the crowntree, the weight of the sweeps forward should have been counterbalanced with ease by the greater part of the body lying aft, added to which were the weights of the rear steps and the dresser. The internal height of the body is 23ft, and in plan it measures 20 ft by 11ft. It is covered by white-painted 6in weatherboarding with a 3in overlap. There is much bracing of the bodywork by iron ties and brackets, and the crowntree has four such ties running down to the underside of the spout floor. Additional side girts were at some time housed in over the existing ones to reinforce the structure.

 The windshaft tapers from 8in square at the brakewheel and 6¼ in square at the tailwheel to 5¼ in square at the tail bearing, and with it the sail canister is cast in one piece. The neck journal, 11in long by 10½ in in diameter, ran in a brass bearing. The striking rod, 1¼ in in diameter, projects from the rear of the tail bearing and out behind the mill where it takes on a rectangular section with a rack cast into the upper face; the underside runs on a roller. The 4ft striking wheel has an iron spider and wooden segments around its circumference; on its spindle is mounted an iron pinion which meshes with the rack, and an endless chain formerly hung over the wooden rim of the wheel and was manipulated from the top of the rear ladder. Mills such as Reigate Heath and Holmwood had a similar feature.

 The brakewheel is of wooden clasp-arm type nearly 9ft in diameter, and with 111 cogs; it is probably the original wheel adapted for an iron shaft. However the tailwheel is probably of later date; it is 8ft diameter, entirely of iron, and is cast in two pieces bolted together – the rim to the spider. The cogs, which number about 100, are jammed into the wheel with the shanks held tight by a wrapping of coarse canvas, and as a further security they are keyed in at the rear, that is on the side facing the brakewheel. The wheels drove a pair of 54in peak stones in front and a pair of 52 in French burr stones behind through iron stone nuts numbering about 16 teeth each, cast integrally; in addition the driving wheels both turned auxiliary machinery. On the left side of the brakewheel a small solid wooden pinion of 20 cogs, coupled directly with a belt pulley, drove through the latter a three-step wooden pulley below. This had a second belt position and provision for a rope drive, and by its means the dresser in the tail was motivated at its upper end. The dresser has been removed, but it was examined in 1933 when in a broken condition and was found to be covered by the rotted remains of a bolting cloth made by Walter Blackmore of Wandsworth. The two bins below remain in situ, the uppermost being considerably the larger. Bolted to the forward side of the tailwheel is a concentric vee-pulley with six wooden segments; this connected with the sack hoist just under the ridge by a rope or chain taken over two wooden guide pulleys. To allow room for the tailwheel and the drive to the rear stones the floor behind the crowntree was set 7in lower than that in the breast. The bins above the stones extended from the rear of the mill to within 1ft of the brakewheel, so that space was at a premium in this part of the mill. The brake is of wood, extending through an arc of 300 degrees, and the heavy wooden lever projects over the first-floor steps where it is bored for the brake rope to hang below.

 The spout floor is conventionally arranged. The footstep bearing of each stone spindle is supported in a cast-iron bridging box with four keys for adjustment. The forward bridge tree is set fore and aft in the breast; the rear bridge tree is set across the mill and is carried on a short wooden bray at the left side of the mill body, as at Outwood. There were two governors with iron arms and lead weights; one immediately behind the tail stone, and the other on the right-hand side of the head stone; both they and the stone spindles were fitted with wooden belt drives.

 The roundhouse has little that is not commonplace; the wall was laid with some artistry, having a decorative pattern in the brickwork halfway down; and bottle-glass window panes were fitted above one of the doors. The ends of the 23ft crosstrees protruded slightly through the walls and were there housed under weatherboarding.

GB: A nice little feature missed by Farries in his inspection is the cutting of two slots in a joist on the spout floor for the belt drive to one of the governors to pass through.


Smock mill, rebuilt on original base



Ockley mill was of special interest; it had the primitive quality of “woodenness” to an even greater degree than Shiremark Mill, since the wallower and the worm for winding both escaped replacement by iron examples. The brake wheel and great spur were unusual, especially the latter.

 The octagonal base of red brick was 21ft across, measured outside, the brickwork being 2 ft thick throughout, and stood 9ft 6in above ground level. There was a single door on the west side and a window on the east side. A wooden stage 5ft wide, level with the top of the base, was supported by iron stays or struts inclined at about 45 degrees.

 The eight cant posts were 34ft long, 10in sq. in section, and mortised at the top into the curb; the tenons measured 10in wide, 2in thick, and 5in long, and were offset a few degrees to allow them to enter the curb vertically. The curb, 10in square and 12ft in diameter, was built up from sixteen pieces of timber, comprising two rings, upper and lower, each made from eight segments mortised together. Half the depth of the mortises for the 48 cogs was formed in each ring, and the rings were pinned together, breaking joint. The curb was iron-shod inside for the truck wheels, and on top for the cap to turn on, a sliding contact or dead curb being employed.

 Intermediate framing consisted of a central vertical member and diagonals. On the lowest section four diagonals in each panel formed a diamond pattern. Two doors gave access to the stage. The weatherboarding was unusual in that the upper half of the body had vertical boarding laid over the horizontal. This feature was observable in some other English mills but was commonly favoured on the Continent. It appears to have given satisfactory results, but tradition tipped the balance against its widespread adoption here.

 The cap and storm door arrangement bore a noteworthy resemblance to that on Jolesfield smock mill in Sussex. A pair of sheers 10in square formed the basis of the cap construction. The truck wheels were of iron, 8½ in in diameter by 2in thick, and carried in wooden brackets, some being secured to the undersides of the sheers, there being no cap circle. A deep vertical-boarded petticoat was fitted to the cap.

 The winding gear was controlled by a chain from the rear of the cap to the stage. The Y-wheel was of solid wood with iron forks, and operated, through iron reduction gearing, a solid wooden spur gear of 24ft 4in diameter with wooden cogs. This gear was mounted directly onto the left end of the large wooden worm, which meshed with 48 wooden cogs of 9½ in pitch mortised into the mill curb, and thus turned the cap. The wooden worm itself was of some interest, being the last example in Surrey of a once common feature, cheap and easy to replace; a relic of the days when the millwright used wood for the solution of most of his problems. It was 7ft long overall, and 12in in diameter. The thread – left after the spiral cut had been sawn and chiselled out from the solid blank – was 6in wide. The cut was 3in wide and 2¼ in deep at the centre, becoming shallower on either side.

 There were four double-shuttered anti-clockwise patent sweeps about 66ft across, with the leading shutters not appreciably smaller than the driving ones. Each sweep had eight bays of four shutters, and a ninth (inner) bay with two only, making 34 double shutters in all. The middling was 41 ft long and only about 10in square at the centre, a small section for sweeps of this size. Pairs of tapered timber clamps, 11 ft long and 6in square at the centre, strengthened the middlings. The striking gear control was by a 3ft 4in diameter four-armed iron wheel mounted on a sloping wooden frame which looked as though it was slipping out of the back of the cap.

 The windshaft was of iron, 11in in diameter at the neck journal and 8in square at the brake wheel; it tapered to 5in square at the rear, and to 4½ in diameter at the tail bearing. The canister was rather small, each socket being 18in long and 13in wide, with sides 1½ in thick.

 The brakewheel was of wood and iron, 8ft 6in in diameter, built up as follows: the iron hub was made in two parts fashioned like face plates, each 3ft in diameter, and these were keyed on the windshaft close together, leaving slots for the twelve iron arms. Each arm was a separate casting, socketed in and bolted to the hub. The arms were of flat section with small central ribs; they tapered towards the outer ends, having spade lugs about 8in wide by 5in deep for connection to the cants. There were six amall wooden cants, 12in deep, and curved on the inner as well as the outer edges. The spade lugs, ¾in thick, were sunk flush into the rear faces of the cants and secured with two bolts, two arms being joined to each cant. The wooden rim in six sections, breaking joint with the cants, was 8in wide and slightly beveled. There were 84 wooden cogs of 3½in pitch and 4in face. The thickness of the wheel edge for braking purposes (rim and cants) was 9½ in., and the wooden brake was 9in wide and 3in deep.

 The wallower, completely of wood, was 3ft in diameter, with 34 wooden cogs. It was made of two discs, upper and lower, connected with eight bolts, The cogs were pinned through the shanks with iron pins from the tops.

 A single piece of pine formed the upright shaft, which was 16-sided, 18in across the flat near the lower end, and tapering a little above; it was 23ft 6in long overall. Wing gudgeons secured with iron bands formed the top journal and the footstep bearing. The foot of the shaft was set on a wooden sprattle beam standing across two parallel main beams running the full width of the body. These beams also indirectly supported the three wooden bridge trees for the stone spindles; the bridge trees were set tangentially to the spur gear and were controlled by wooden brays.

 The sprattle beam was of the old type, arranged to be shifted bodily for adjustment by wedging. Shoulders for wedge abutment were commonly cut direct on the members concerned, but at Ockley tapered wooden chocks were spiked and bolted in position to serve. Six of these were needed, an opposing pair on the top surface of each supporting beam, and a large inverted pair on the underside of the sprattle itself. Adjustment was thus possible across the width and along the length, and the variable combination of both enabled any position within the limits of the scheme to be obtained for the footstep bearing. This employment of wedges and similar devices for effecting fine adjustment to working and structural parts was close to the heart of millwrighting. Comparison of types of sprattle beam in use at the late surviving Surrey smock mills is interesting. Here at Ockley direct adjustment of the whole beam was used, the bearing pot being fixed, while at Outwood and Shiremark the beam was fixed, and carried a wedge-adjusted bearing block. Trumpets Hill also had a fixed beam, but with a screw-adjusted bridging box. Thus the oldest system was in use at the latest mill, and the latest system in use at the oldest mill – a not unusual paradox resulting from changes in gear and equipment over the years. All three types were equally efficient if used correctly, the progressive effect being in terms of convenience.

 The great spur gear, 9ft in diameter, was an all-wooden wheel of very great interest, being in fact a combined spur gear and downturned face gear (slightly beveled), the latter for machine drives, with both sets of wooden cogs, of similar pitch, mortised into the same rim alternately at right angles to one another. Each gear ring consisted of 108 cogs. There were two sets of cheap arms set “over and under” the six cants, and a rim in six sections built up on the underside of the cants. The wheel was fitted to the lower end of the upright shaft. Stone nuts of the all-wooden type, 2ft in diameter and 10in deep with twenty-four cogs, were fitted. They were disengaged by removing slip cogs, and held steady by hooks and staples. A small wooden pulley was fitted on each stone spindle for belt-driving the governor. The three pairs of overdriven stones, two burrs and one peak, were located approximately on the north, east and west of the great spur. For each revolution of the sweeps the stones turned just over 11.1 times.

 Two drives at least were taken off the face gear on the underside of the great spur, by means of pinions on horizontal shafts. On the north side, the pinion, its cogs and its shaft, were all of wood and drove a flour dresser on the stone floor. On the south the shaft was iron, but details of the pinion and the purpose of the shaft were not obtained. The sack hoist was friction-driven from the underside of the wallower.


Post mill, standing today


Farries: Today the mill retains its ancient, if unexceptional, character although a number of the original timbers have been replaced; gaping mortices and the vestigial remains of earlier fittings lay emphasis upon its great age. The rear of the stone floor was formerly at a lower level, and the present tail beam lies 1ft behind an earlier one. The side girts have been duplicated, the newer (uppermost) members being butted to the vertical corner posts and secured by iron brackets cast at 100 degrees. A cross member in the breast of the mill below stone floor level has been deeply hollowed to allow clearance for the arms of the forward governor, and the rear of the body has evidently been extended several feet to accommodate a flour dresser in the tail. The fine oak crowntree, 21in square, bears the inscription 1880, and the oak centre post may well not be the original.

 The substructure is in oak, and is housed in a roundhouse of 22ft internal diameter. The crosstrees and quarterbars are each 12in square, and are inclined less steeply than usual, the angle of the quarterbars with the upper crosstree being about 38 degrees. Rectangular wedges 3in by 4in steady the base of the post at the junction with the crosstrees, the latter being cut away to accommodate them flush with their upper surfaces. Further steadying is achieved by a wooden collar, which is set on four chamfers round the post at the base of the sheers, and gives some support to the latter; they measure 11½ in by 9in and run fore and aft at the base of the body, curving downwards at the extremities – in the rear to accommodate floor joists and the seat of the tailpole. The post, whose overall height is 16ft 3in, is fitted with a samson head below the crowntree, whither it tapers to 16in in diameter from 29in square at the base. The sheers pass on either side of the post at its middle point.

 The most noteworthy features of the mill are the older components, which include the windshaft, tail wheel, stone nut and sack hoist. The windshaft, inclined at approximately six and a half degrees, is of oak, tapering through 12ft from 23in diameter behind the neck bearing to 13in in front of the tail bearing, both bearings being cast integrally with cross-tailed gudgeons let into the shaft. The forward casting is inset to a depth of 30in and bound with two 2in metal straps. The brake wheel is an 8 ¼ ft conventional clasp-arm wheel with double arms of 11in total depth. There are 108 cogs of 2½ in pitch mortised into the eight segments forming the rim; they are pinned at the rear by nails. The rim has a metal band of 0.2 in thickness and 8in width held by countersunk screws, to act as a braking surface; the wooden surface so protected had been worn down to the outer ring of dowels. The brake, which is in five segments, is operated by a lever 11ft long hinged on a peg, all being in wood; the lever is scarf-jointed and iron-strapped towards its outer end, where a repair has been effected. At the extremity are the customary pulley and peg, and above is an iron catch or release hook for the peg, enabling the miller to brake or release the mill sails by pulling on the brake rope from ground level.

 The tailwheel is of solid oak in its outer section, where the four segments, which leave a nearly square open centre of about 47 in. side, are halved at the overlap and notched in at the back, running right through to the outer circumference. They are securely dowelled. Four old arm beds, cut along the centre lines of the segments, are filled in with wooden blocks, and an eight-armed spider, cast in two segments, is bolted to the assembly. There are 84 cogs of 3¼ in pitch, pinned at the rear with nails.

 The brake wheel drives a 4ft peak stone, used for oats and barley, through an iron nut of 13 cogs, and the tailwheel meshes with a nut of older type, consisting of a solid wooden drum closely resembling the hub of a cartwheel. This turns the French stone for wheat and maize grinding. Both nuts are put out of gear by the unwinding of a screw which releases the pressure on the brasses in the glut box and allows the quants to be withdrawn. The “barrel” of the tail nut is bound with iron at top and bottom to prevent slipping, and the 13 cogs are held by long bolts running through from face to face.

The head and tail stones, which revolve 8½ and 6½ times respectively for one revolution of the sails, each have a governor mounted on the spindle below.

 Both the brake and tailwheels drove additional machinery. At the left-hand side of the brake wheel a solid wooden pinion with bolts taken through the drum to hold the 24 cogs powered an oat crusher in the floor below, now gone. There was a belt drive. The pinion was thrown out of gear by a pivoted wooden lever. The raising of sacks is beset with difficulties consequent upon the restricted space within the body, whose floor dimensions are 18ft by 11ft, with only 6ft between the crowntree and the breast of the mill. There are two units involved. A drum, friction-driven from the top left hand side of the brakewheel rim, winds up a rope from the section of the sack hoist barrel proper of wider diameter than the remainder of the barrel fore and aft. From the latter the sacks are lifted, a reduction of effort being thereby gained. The barrel extends from the brakewheel to the rear of the body under the apex of the roof, and the forward end is used to raise sacks from the roundhouse to the spout floor, while the rear end brings the sacks up further through a trap in the left rear of the mill to the three small bins above the tailstones. Even with this tedious two-stage arrangement the lifts are not vertical, and a pulley is let into the floor behind the crowntree to guide the hoist rope clear of the tailwheel. Here there is no space for trapdoors. This hoisting system emphasizes a serious defect of the older post mills.

Smock mill, gone


Farries: A portable steam engine was already in use at the mill when the Scotts assumed ownership; it drove a pulley at approximately stone-floor level. Two pairs of stones were normally driven by the engine, but it was not used after the early 1890s. To break the transmission through the mill four cogs were slipped from the brakewheel.

 In its day the Outwood smock mill was probably the finest of its type in Surrey. It had the distinction of being the largest smock mill in England, measuring 62ft to the top of the cap, all but 2ft being of timber construction. A few others were taller, but they had a normal-sized timber framework mounted on a high base. The mill therefore merits the full description given below by Mr Denis Sanders:

 The base, of red brick, was constructed barely 2ft high, and 26 ft across, measured outside. The courses were stepped slightly, inside and out, and at ground level were 2ft 6in thick. The top course, 18in thick, consisted of two rows of headers, inner and outer, and on these the wooden sills were laid; they were 10in wide and 6in thick. At the corners the sills were connected by iron straps outside and shaped wooden members inside; the latter were 2ft 8in long and 6in square at their centres. Bolts were passed through the whole assembly, making very strong joints. The eight cant posts were of pine, 11½ in square, and 48ft long, and the wooden curb was of 13ft 6in diameter and about 12in by 9in section.

 For each of the four floors above ground level there was a set of eight transoms. These were tenoned at each end, let into mortices cut in the cant posts, and pinned in place, thus tying the posts together. The floors were supported on the transoms. A pair of parallel beams of heavy section was set across two opposing transoms on each floor, and the joists were supported by the beams. It is usual to find that the beams run in alternate directions on successive floors. They are also arranged to act as ties, and at Outwood what are known as dovetail checks were used for this purpose. On the underside of each beam where it bore on the transom a large single dovetail 2in deep was formed, and this fitted into a dovetailed housing cut on the upper face of the transom. The shoulders of the dovetails on the beam bore against the inside edges of the transoms, so the beam acted as a distance piece also. Thus the side frames were prevented from closing inwards or spreading outwards; the tower was spaced and tied all the way up, alternately in each direction, and the result was a structure of great strength. The transoms bearing the floor beams were 9½ in deep by 6in wide; the others were 6½ in deep by 4in wide.

 In order to carry the floor joists in the most convenient manner, the pairs of opposite transoms bearing the main beams were fixed about 6in lower than the others in the same set. This arrangement allowed the joists to be mortised into the beams as required, with their top surfaces flush with those of the beams, and also to be carried at their outer ends by the other transoms, on to which they were shouldered. The joists were trimmed as necessary for the sack traps and ladder wells, and boarded over to form the floors.

 An unusual feature was that the ground floor was 3ft above ground level, and of timber construction. The floorboards were laid on joists of irregular shape about 4in square, dressed on the top surfaces only, in many cases. They were supported on wooden beams 4in wide by 6in deep on 4ft centres, set across the base and carried intermediately by dwarf brick piers. The ground floor joists were in marked contrast with those on the upper floors, which were of dressed timber of rectangular section, with the larger dimension set vertically. All transoms, intermediate framing and floor beams were of pine.

 In the centre of each of the three lower floors was a vertical oak post 8in square giving central support to the floorbeams. A short brick pier in the middle of the ground floor carried a wooden template level with the floorboards. The bottom post was footed on this, and supported across the top on an 8in square beam 5ft long, set beneath and at right angles to the first floor beams; these were 10in square, on 4ft centres, and ran east-west. The second post stood on the top centre of the 5ft beam, and rose through the first floor to support a short cross member carrying above it a pair of horizontal timbers 8in square on 14in centres. These were set between and at right angles to the second floor main beams, and were mortised into them; the beams were 11in square on 5ft centres and ran north-south. They supported the millstones, as described below. The third post stood on the cross member and rose through the second floor to bear on the underside of the horizontal bridge beam or sprattle carrying the footstep bearing of the upright shaft. It was necessary for the sprattle to be set lower than the floor beams, which supported it and with which it ran parallel, in order to give clearance for the great spur gear on the upright shaft. The sprattle was therefore bolted up at each end to a short cross beam, and these two beams were each suspended from the floor beams by two vertical wooden distance pieces.

 The intermediate framing was of an unusual type. Each panel was divided into two sections by a horizontal member 6½ in deep by 4in wide mortised into the cant posts at either end. Above and below this central vertical posts 3/2 in by 3in were fitted, with diagonal brace 4½ in by 3¼ in in each of the four small panels thus formed, the overall pattern resembling the Union Jack. All framing members were fixed with the larger dimension flat to the tower. Where the doors occurred the horizontal member was set high, forming a lintel, and two door posts were added; two short diagonals above and two long ones below the lintel followed the general pattern. Vertical studs, 2½ in by 2 in, on 9in centres, were fixed between the frame timbers, and the weatherboards were 6in wide, lapped 2 1.2 in. Wedge-shaped “tilting pieces” 2ft long were nailed on the outside faces of each of the cant posts, vertical and studs, just above the base, to incline the lowest sections of boarding outwards in order to throw the rain well clear.

 There was a wooden stage built round the tower at first floor level, about 11ft above ground, but this later disappeared. On the outside faces of the cant posts at this level vertical wooden members 2ft long and 6in square were bolted. These were mortised at their centres to take the inner ends of the former horizontal radiating beams of the stage. The outer ends were supported by inclined wooden struts footed into smaller mortised wooden blocks secured to the cant faces lower down. Additional support for the stage was given by struts at the centre of each “flat” of the tower.

 Construction of the cap followed that at Trumpets Hill in general, the size being about 16ft long by 12ft 6in wide, by 11ft high over the curb. The cap width being less than the curb diameter, it was necessary to construct “blisters” on either side. The sheers were 9in square, and the curb was live, the cap turning on iron rollers 6-in diameter by 4in wide, seven under the head, two on each side and three at the rear, with eight truck wheels which kept it central to the tower.

 For winding a large five-bladed fan, long missing, was mounted on a substantial frame with inclined braces passing into the cap. The fan drive came down to a bevel pinion meshing with a gear about 4ft in diameter, and on the same horizontal spindle a spur pinion engaged an upward-facing iron rack fixed on the top of the curb, so turning the cap.

 One pair of double-shuttered sails remained to the last, with a span of 80 ft. The stick was 46 ft long, 14in square at the centre, and tapered to 7½ in square at the tips. There were four features of special interest. First, the number of shutters; the inner bay had four, then there were eleven bays of three, and then two bays of two – fourteen bays with 41 double shutters. Four sails like this would have a total of 328 shutters. Secondly, the sails were of spring-patent type, with double half-elliptic springs fitted at the inner end of each sail, and connected between the bell-crank and the shutter bar. This arrangement gave each sail a certain measure of independence, but reserved the convenience of overall control of the patent gear. Thirdly, the stock had no timber clamps at the centre. Instead, two iron members 14ft long and 6in wide by ¾in thick wre fitted; they wre joggled over the canister and bolted to the stock. Fourthly, from the back of each end of the stock a wooden member about 7ft long extended outwards to reinforce the outlying part of the whip. The inner end was secured by the iron clamp round the stock and whip, the outer end being faced on the back of the whip. In effect this member triangulated the joint. The backstays from the driving side at this point were also fixed to it. This fitting was used on the sails at Ockley mill and elsewhere. Control of the sail shutters was by means of a large iron chainwheel below the back of the fan stage, set flat to the tower on a shaft which passed forward to the cap. A pair of small iron bevels brought the drive to a pinion engaging the rack fixed to the striking rod. The control chain hung down to the stage, and a long wooden guide to prevent its becoming entangled was supported from the fanstage.

 The windshaft was of iron, 11½ in in diameter at the neck, 8¼ in square at the brakewheel; it tapered to 6in square at the tail. The brakewheel was 9ft 10in in diameter. There were twelve iron arms of tapering + section cast in one piece with the hub, which was 10in square internally and keyed on the shaft; the casting was 10½ in deep at the centre. The cants, rim sections and cogs were wooden. There were eight cants, so that one arm and two arms were bolted to them alternately. The 100 cogs were of 3½ in pitch, and were set in the slightly beveled rim of width 7½ in. Evidence remained to show that the wheel had originally eight compass arms 2¼ in wide, and was later converted to clasp-arm with 5in arms on 35in centres. This metamorphosis corresponded to three successive techniques in the mounting of brake wheels. The overall thickness of the wheel edge was 10in; the brake was of wood, in sections, and the wooden operating lever was held in the “off” position by an iron catch.

 The wallower was of iron, 4ft in diameter, and had eight arms. The hub was octagonal and was 21in across the flats internally. This wallower was fitted by the Scotts to replace one 4ft 8in in diameter which remained on the dust floor, the object being to speed up the revolutions of the stones. The earlier wallower bore the inscription S.M. & Son, 1864 {Medhurst?}.

 The upright shaft was wooden, 16-sided, 20in across and in two sections, with a coupling at dust floor level. The coupling was a cast-iron dog clutch with eight dogs, the units being let into the shaft with cross-tailed gudgeons. At the top of the shaft the journal was carried by the spindle beam, 9in square, and at the bottom the footstep bearing was adjustable in the early manner as described for Shiremark. A metal block carrying the bearing was set in a housing in the supporting beam, and adjusted as necessary with four wooden wedges.

 The all-wooden great spur gear was of compass-arm type, 8ft 8in in diameter, with 120 wooden cogs. The rim, 7in by 5in, was in eight sections, and eight arms or spokes 8in by 2 ¼in were mortised into the base of the upright shaft. Beneath the great spur, secured to the spokes, was a wooden bevel gear of 5ft 8in in diameter, with six cants, a built-up rim, and sixty-flour down-facing wooden cogs, but it had no spokes of its own. Three of four cast-iron stone nuts finally remained; they were 20in in diameter and had four arms. Two had 22 teeth and the other had twenty.

 Each quant was in two pieces, with a flanged coupling, the lower part 7ft long, the upper 2 ft 6in long. The stone nut was keyed on the upper section, which was mounted in a rectangular wooden frame with two bearings, upper and lower. The nut with its shaft was free to slide up and down to enable the couplings to be mated. The rectangular frames, or carriage pieces, set vertically and carrying the stone nuts, were mounted on runners and guides in wooden box frames secured to the ceiling, and were thus able to be slid towards or away from the great spur gear, in or out of mesh, and locked in position as required. To engage a pair of stones the foot of the long quant was set on the runner stone, and the upper section, with the stone nut, raised by means of a special inserted lever; the lower part was then brought vertically into alignment, and the upper dropped a few inches, so that the dogs on the couplings located. Final adjustment for correct mesh with the spur, and locking of the carriage piece, completed the operation. Different shaped dogs were used for coupling, to avoid confusion. Removal of the lower quant sections was necessary only when raising the runner stones for dressing.

 Ratios of sweeps to stones were as follows. With the larger (earlier) wallower, for each revolution of the sweeps the 22-tooth nuts turned 10.9 times, and the 20-tooth nut 12 times. The smaller wallower gave 12.5 and 13.8 revolutions, respectively, in the final arrangement. Probably the large sweeps turned ponderously, making the change desirable. It was necessary to realign the brake wheel and the brake when the wallower was replaced with a smaller one; both were brought about 4in to the rear. The tips of the sweeps described a circuit of 250 feet; at 12 rpm their speed would be 34 mph, and at 10rpm 28 mph. In contrast the 60ft Shiremark sweeps covered 188 feet in a circuit at the tip, and at 12 rpm their speed was 25.5 mph.

 Four overdriven pairs of stones were fitted, set more or less on the four points of the compass with their centres on a circle approximately 10ft in diameter. Two pairs of strong horizontal timbers mortised between the stone floor beams supported the north and south bed stones, while those on the east and west were on pairs of timbers which were mortised into the outside edges of the adjacent beams, and ran across to bear on the transoms. Two pairs of 4ft diameter stones remained, and there was a 4ft 4in diameter bedstone still in position until the end, but the south stones had gone. All were enclosed in octagonal wooden cases. Two of the French stones had the markings “Clarke and Dunham 1859” and “Hughes Dover Rd London” respectively.

 Suspended beneath the stone floor by vertical wooden members were the four wooden bridge trees 9in square and 6ft long, which all ran east-west, and had twin tenons at the fixed ends, and wider single tenons at the controlled ends fitting in mortises cut near the lower ends of the supporting members. These members, or hangers, were 10in square and 3ft 6in long. Two pairs for the north and south bridge trees were mortised directly into the undersides of the floor beams. Two others were halved at the tops and bolted up to the outer edges of the floor beams centrally in the mill; the inner ends of the east and west bridge trees fitted into these, with another support hung from the stone bearing beams for the outer end of the west bridge tree, while that on the east had no hanger at its outer end, and was supported only by a wooden bray. Three of the bridge trees, north, south and east, were controlled by long horizontal wooden brays which were set at right angles to the bridge trees and carried their free ends. The west bridge tree had no bray, the steelyard from the governor being pivoted over the free end, and a vertical iron strap a few inches from the pivot was connected directly. The three brays varied in size, but all operated identically. As an example, the north bray was 7ft 3in long overall and about 4in square, and was suspended from the stone floor by a wooden member about 4ft long, to which one end was pivoted. The free end of the bridge tree was supported 2ft from the pivot, and the bray ran across to the framing on the north side of the mill. The end was tenoned and worked up and down in a slotted timber secured to the framing. The steelyard from the governor was connected to the bray at this point, so that the gap between the millstones was directly related to mill speed. Three of the bridgetrees had initial adjusting screws at the fixed ends, but that on the east side was without one, and was set up as required by packing beneath the tenons. All four bridgetrees had bridging boxes, each with four adjusting screws to enable the stone spindles to be set vertically. A governor for each pair of stones may formerly have been fitted, and the three remaining stone spindles each had a pulley for driving one. In the final arrangement however only two governors were used, one for the south and east stones, the other for the north and west ones. Each governor was belt-driven from one of the two stone spindles associated with it.

 An outside pulley for engine drive was mounted on an iron shaft which came in to a pair of iron bevels in the ceiling of the first floor – one had wood cogs – and the drive was taken above by an iron shaft to another pair of bevels on the stone floor, where an iron pinion engaged the down-facing wheel below the great spur gear. A second and similar pinion could be raised into gear with this wheel by a wooden lever, to drive an inclined wire dresser on the east side of the stone floor, the drive being by a 3ft diameter iron bevel wheel with wooden cogs, to a small iron bevel pinion on the rotor.

 A spur pinion similar to the stone nuts engaged the great spur gear for a drive to an inclined wire dresser on the ground floor, latterly missing. The pinion was on a vertical iron shaft, which passed down through the first floor to the ceiling of the ground floor, where the drive was by bevel gears to a horizontal shaft and further bevels to the rotor.

 Below the wallower was secured a bevelled wooden friction ring to drive the sack hoist. A 20in diameter bevelled iron friction wheel was mounted on the chain bollard, which ran across to the side framing. Control was by a rope and block multiplying gear, the rope extending down through the floors.

 The mill was packed with interesting minor examples of the millwright’s resource and skill in woodworking. Small and large brackets of all kinds, stays and struts without number, tool racks to hold mill bills, and so on; all were here in profusion, but the foregoing description has necessarily been confined to the main features of the mill’s structure and equipment. Details of the third floor, where the corn bins were situated, and of the top (dust) floor, have been omitted.

After the mill’s collapse Mr Sanders inspected the wreckage and wrote the following commentary:

 “A form of “secret” fixing (known today as a handrail bolt, used to join lengths of wooden handrailing end to end) found at least two applications at Outwood smock mill. The wooden cants of the brake wheel, and the sections of the main sills of the smock body, were connected together by this means. This was discovered where the sills had almost rotted away, and where the brakewheel had been torn apart. Two opposing holes were bored in the meeting faces of the members, and a nut on each threaded end would bring the faces tightly together, the rod and nuts being within the thickness of the timber.

 The means of achieving this were as follows. Each bored hole extended into the member 8in or 10in, in the case of large parts, and less in proportion for smaller, and mortices were cut in the sides of the members to allow the nuts to be inserted. The mortices were at right angles to the holes, to give full clearance for the nuts. To assemble the joint, one nut was dropped into its mortices, and the rod inserted and screwed up fully. This was the easy half. The second nut was formed with ridges on its outside edge, so that it could be tightened by hammer with a punch inserted in the mortice. The second edge of assembly was to bring the members together, introducing the rod into the outer hole, with the nut loose in the mortise, and gradually start the nut on the thread. Once started, the hammer and punch closed the joint tight, and when all was secure hardwood pellets were driven into the mortises and cleaned off flush.

 A number of adjusting wedges were used throughout the mill, as at many others, and the form that these often took is worth noting. Along the length the necessary taper was cut, usually three or four degrees only; to prevent them jumping out like lemon pips when driven, their section was cut as a slight dovetail on one side, and the recess to take the wedge similarly shaped. They were thus locked in position, and self-retaining, and even when inverted were quite safe and secure.

 The structural framework and fittings in general of this mill were of outstanding quality. Many of the timber joints had been painted before assembly, and the outer face painted before weatherboarding. The fact that the boarding, 6in wide with 2½ in overlap, had been so well fitted probably accounted for the mill’s long “shelf life”, almost fifty years, during which no maintenance at all was carried out. It did not account for the extended life of the stock and two sweeps, which made a 95ft landmark for so long.