Posted on

Technical descriptions of English windmills



Smock mill, standing today


Upminster smock mill has gained rather than lost in its complement of ancillary machines and drives since it fell idle, and concedes hardly a dull corner.

 The mill stands 52ft to the top of the cap, and the smock frame rests on a single-storey brick base with vertical walls inside and slightly stepped brickwork outside, reducing the thickness from 34in at ground level to 18in at the sills. The massive cant posts, in pine, are 34ft long by 13in wide and 11-12 in deep, and the octagon they form at base is 27ft 9in across the flats, diminishing to a circle of diameter 14ft inside the curb. The cap overhangs the body comfortably at front and rear, having a fore-aft dimension of about 17ft 6in internally and 16ft 10in across. The dust floor is 6ft 6in high to curb level, and in order downwards follow: bin floor 6ft 10in; stone floor 10ft; spout floor 10ft 3in; ground floor 9½ ft. With measurements of 24ft and 27¾ feet across the flats inside the weatherboarding, the stone and spout floors respectively are very roomy, taking four pairs of stones and auxiliary equipment with ease.

 The framing in each panel between cant posts and transoms consists of an intermediate post 8in sq, tenoned into the transoms above and below, with a single dowel through each joint, and two upwards-converging diagonals 4½ in by 3½ in, footed in the transoms and set into the intermediates above. Studs, about 2 ½ in sq on either side, for further weatherboarding support, are tenoned into the transoms and spiked to the diagonals. In the spout floor panels there are three stud positions on either side of the intermediates, but owing to the convergence of the cant posts there are two on the stone and bin floors and only one on the dust floor.

 The transoms, typically 8in across by 7in deep, enter the cant posts bodily for about 1½ in, leaving 1½ in uncut on the inside faces of the posts, and then extend a 3in thick vertical tenon for a further 4½ in into the post, probably using the full depth of the timber, viz. 7in. These joints are also dowelled to prevent withdrawal.

 The sills, into which the cant posts are footed, are 12in wide by 6in deep, and about 11ft 8in long overall; the two sets of timbers were united by iron brackets according to a note by Denis Sanders (c1950), and presumably tenoned also, but the details are hidden. The tops of the cant posts are spaced at 5ft 5in on centres where the 12in by 10½ in curb sections are dropped over their vertical tenons, and the 8 curb segments are edge-halved horizontally and butted together in a scarfing scheme using vertical butts and an overlap of 8in to 10in, the simplicity of which is in striking contrast to the intricacy of the joints at Baker Street. Alternate segments have two base extensions and two upper extensions for overlap. The present curb was with little doubt the replacement for an earlier one, for it contains no trace of wooden rack cogs. It carries iron channels for the shot rollers to run in, as later described.

 The floor beams, 12in square at every level except for the dust floor, where they are a little lighter, run north-south on the spout, stone and dust floors, and east-west on the bin floor. The first-floor beams are let into the brickwork, but the others in all cases rest on dropped transoms and abut the cant posts, which are recessed to give the full surface contact which their angle would not otherwise offer. At South Ockendon, where the cant posts are slighter, it is the floor beams which are trimmed to the cants. The spacing of the floor beams at Upminster necessarily decreases upwards as the sides of the frame converge. From 8ft centres across the beams on the spout floor, the span has narrowed to 6ft 4in on the bin floor. A refinement noted is the depth of the recesses in the cant posts for the lodgement of the floor beams; the recess decreases as one proceeds upwards, being 4½ in at the visible corner at stone-floor level, 3in under the bin floor, and 2in under the dust floor.

 The first-floor beams are supported from below by two wooden stanchions in each case, having two folding wedges driven in at the head to ensure that all four share the load at all times. The posts are spaced 8ft north-south, and 8ft 6in east-west overall. A fifth post, in oak, and matching the others, is a modern addition to support further the east floor beam. Above, on the spout floor, is another set of four 12in sq posts, forming the “cog box” within which the great spur gear rotates; this set of pine posts is approximately 9ft east-west by 8ft north-south overall, and supports the stone-floor beams above. The space below the great spur and within the posts is partitioned off by wood panelling up to a height of about 6ft, with a door giving access from the south side, where is also a hinged flap. It served, perhaps, as the “pastry”.

 The stone floor carries no supporting posts for the bin-floor beams, but the bin floor has four posts halved onto the fourth or dust-floor beams. These are not, however, for floor support. Halved onto the inner faces of the posts about 3ft over floor level are two horizontal 10½ in by 5in timbers, which carry between them a 10in sq bridge piece running east-west for the intermediate bearing of the upright shaft just below the universal coupling. This bridge is double-tenoned and well wedged at each end into the two 10in by 5in timbers, and the whole assembly, in clear-grained pine, is stop-chamfered and cleanly executed. This constriction must date from 1876, when the upright shaft is said to have been broken and therefore converted into two sections. The coupling is of elaborate design and extends through 2ft; it readily allowed the disengagement of the wallower from the brake wheel, described below.

 The mill cap, with its broad boat shape, iron-railed gallery and skirting, is an eye-catching feature, but one must beware of regarding it as necessarily original. It is likely that the mill started life with a wooden winding worm, as used at South Ockendon mill throughout its working life. The basic cap framing accords with Essex practice. The sheers, 12in square and on 10ft 10in centres, run parallel from front to rear of the cap, being contained within the skirt at front, but projecting about 3in beyond the weatherboarding at the rear, where they are covered by metal sheeting. Five transverse members extend between the sheers, each with its distinctive function. The weatherbeam, 12in deep, forms the forward cap shape, being 18in fore-aft at centre and 12in at the ends, where it sits in a rebate cut in the sheers; it is tilted slightly forward under the load of the windshaft as is commonly the case. There has been considerable movement at the sheers-weatherbeam junctions, with remedies sought in heavy iron dogs. The late-added roller-bearing box for the neck journal of the windshaft is blocked up on timbers laid across the weather- and first tie-beams in the fore-aft sense. The tie beam, 28in on centres behind the weatherbeam as measured at centre, is 10in sq, and is double-tenoned into the sheers and dowelled, but slight gaps at either side indicate an outward movement of the sheers of about 1¼ in, to counteract which they are tied by a 1½ in by ½ in iron strap passing across behind the tie beam.

 From the tie beam two timbers run forward horizontally under the weatherbeam to give it support and therefore offset its tendency to turn outwards (two mullions let into the headstock in certain millwrights’ terminology). They project beyond the cap, as the sheers formerly did at front, where they are lead-covered. They are notched over the cap circle which rides over the shot curb, so taking a share of the great weight above, a feature favoured by William Bear, of Ballingdon, millwright, as witness his Buxhall windmill contracts dated 1860 (The English Windmill, Rex Wailes).

 6ft 6in on centres behind the tie beam is the spindle beam, 9½ in sq. which has a plain wooden bearing on the forward side for the pintle of the upright shaft. The beam is cut at either end as in post-mill practice for spindle-beam carriage; a 3¼ in thick horizontal tenon projects over the sheers and a second tenon enters them, while the two rebates have angled cuts both in the vertical and fore-aft senses to accept tapered wedges. These wedges give side-to-side adjustment of the upright shaft and wallower position; fore-aft adjustment was obtained by sliding the spindle beam in the mortices in the sides of the sheers. In the left sheer the mortice is 19in long, giving 9½ in play; on the right it is very long at 35in. The spindle beam tenon on the right side has relieved corners, and could have been introduced, with the opposite end of the beam in position, without displacement of the sheers. If need be, the wallower could be disengaged from the brake wheel, but there is no suggestion that, for instance, this was ever required to confine an engine drive to the upright shaft, since no point of application of engine drive is apparent; neither has the brakewheel any slip cogs.

 4ft 3in on centres behind the spindle beam is the original tail beam, 14in across by 11in deep. This, like the forward tie beam, is twin-tenoned into the sheers at each end, and is similarly paralleled by a tie rod between the sheers, in this case on the forward side, the sheers having drifted here about 1in apart. When a replacement windshaft from a post mill was fitted after the disaster of January 1900, a second tail beam was brought in behind the first, this being 1ft sq at centre and tapering towards the ends. It stops short of the cap circle to its rear, measures only 6ft 6in between the tips, and both supports the tail bearing and guards it against lifting by means of an iron keep above.

 At about 2ft 8in on centres behind the added tail beam is a 10in by 8in tie beam beyond the curb, tenoned into the sheers near their ends, and supporting the rear cap frame and skirting. The rack-engaging pinion turns on a vertical shaft whose bottom bearing is carried on hangers slung from this rear tie beam and the left sheer.

 The fan supports and staging, which lie within about 3ft 6in of the rear weatherboarding of the cap, are based on heavy section pine members bolted to the upper faces of the sheers, having 10ft or so of their length within the cap and 4ft outside. They thicken in depth from 8½ in to 11in before emerging at 11in by 12in in section. At their extremities these timbers are decoratively moulded and a little forward of them carry a 9in square member 15ft 4in long overall, on which the date 1799 was erroneously inscribed on 13th August 1949, as the year of erection of the mill! This beam carries the fan posts, 9½ in by 10 n and 12ft 6in overall on 5ft centres; they are halved and bolted to it. These heavy fan posts, supporting the weighty clockwise six-bladed fantail and heavy iron shafts and gearing, posed a problem in the preservation of stability, the whole being rebuilt in 1927 after the fan had been blown off. There are two tie beams between the fan pots; the higher is just below the fan circle and carried the driver of the second pair of bevels by which the drive is transferred forwards into the cap. Two horizontal iron ties secure the fan posts to rafters near the cap centre, being bolted down into them. The posts are also each in part sustained by no fewer than four triangulating members. A heavy duty pair measuring 5½ in across by 11in deep are tenoned, dowelled and dogged to the old tail beam, and pass outside the fan posts, to which they are bolted. They extend 6ft 6in beyond the rear weatherboarding on an upwards slope and may be said to embrace the posts, for they converge outwards from 8ft 6in centres at the tail beam to 6ft 6in centres at their ends beyond the posts, whence braces about 5in by 3½ in incline up to the rear post faces. 10in on centres forward of the transverse sill for the fan posts is a 7in sq member terminating at the outside faces of the fanstage sheers and laid over them like its larger companion timber. Its function is further to aid in the triangulation of the fan-post footings, which it does by providing a base for comparatively short and small-section diagonal pieces both to the forward and outside faces of the posts. It was fitted in 1972 for reinforcement.

 The overall size of the fan platform is 6ft by 1ft 8in. It is reached through a small door, and is suspended by irons from the framing members. From it, the catwalk, or gallery, leads off to the same level as the windshaft head, and is supported on short horns housed in the sheers and carrying also the cap-rafter circle below, from which the skirt depends, and which circle itself is anchored to the sheers at the 4 points of contact. Certain of the cap members, including the horns and gallery, were replaced in c1950. The cap height above the top of the curb is 8ft 9in, and its shape is maintained by rafters arranged parallel and ending in a ridge piece. The modern laminated rafters are not angled to suit the curved boarding, which accordingly makes contact with their rear edges only, where the curvature of the cap towards the rear becomes pronounced. The total weight of cap, windshaft, sails and fan staging carried by the curb may be estimated at about 8 ½  tons, based on the figures for Mill Green, Ingatestone.

 The curb has 152 iron teeth cast in segments and bolted on outside. They are of 2¼ in face and 4in pitch, giving a pitch circle of just over 16ft. The fan spindle carries an iron bevel gear with 18 teeth meshing with one of 44 on a vertical shaft, with 1 to 1 bevels at about 27in over the fan stage to continue the drive through 90 degrees, and cone spurs 1 to 1 just outside the cap to change the angle a little, taking the drive through an iron worm about 6in across and 1ft long. The 32in diameter iron worm wheel is six-armed, cast solid, and has 44 teeth. It turns horizontally and carries the final driving pinion below on its 2in sq vertical shaft; this pinion is about 1ft in diameter and has 9 teeth. All this gearing is framed up from the left rear of the cap and fan staging. From the various figures given, the ratio of fan revolutions to a full turn of the cap is about 1830 to 1.

 The curb is of the shot type and turns on 30 iron rollers of approximately 3½ in diameter and 3in width, slightly tapered, and about 18in on centres. They are pinned through two containing vertical 2in iron rings following the curb, with cotter bolts passing through from outside and held by split pins inside. The rings are also bolted together independently of the rollers at intervals to maintain their correct spacing. The rollers are free to run round an iron channel set on the curb, and they support the cap circle, 7in wide by 5½ in deep, through an inverted iron channel or trough attached to its underside. This upper fitting is 5in wide by 2in deep overall. As the rollers were confined to the channels above and below, which appear identical, they were proof against lateral displacement. This system may be compared and contrasted with that described for Thaxted.

 The cap circle is held by the sheers in their lower halves, and by the horns which project from them; it appears to enter the sheers at the eight points of abutment and to terminate on a vertical radial plane immediately after making full entry, leaving the upper inverted iron channelling to run through. The sheers are cut away underneath by about 2in for this purpose, since they pass 4in over the top of the curb.

 To centre the cap, eight identical iron truck wheels of 12in diameter and 2½ in face are attached: three at the front, three at the rear and one on either side. The foremost wheel is bracketed below a bridge piece from the forward tie beam to the cap circle beneath the windshaft, the rear one is below the added tail beam; elsewhere they are held under each end of the forward tie and former tail beams and outside the sheer centres. The relation of the wheels to their vertical iron track on the inside curb face tells a story of curb distortion. The square, flat-headed countersunk bolts holding the rack segments in position are secured by nuts inside the curb just below the track, and the centring wheels fouled these at three points in the southerly sectors, beneath which three sills, scheduled for renewal, were rotting badly in 1975. That the trouble occurred during the working life of the mill is suggested by the use of wood packing laid over with pieces of old leather strap on either side of the nut positions, giving a lead for the wheels to pass over the obstructions. It was probably at the date in question already futile to embark on a more radical correction of the trouble, which is open to several explanations. As usual, the centring wheels were not adjustable and, as seen in 1975, were either in contact with the curb or within ½ of it.

 Hand cranking was applied to a square cast on the forward end of the worm shaft, after disengagement of the driving bevel of the pair just outside the weatherboarding by the fanstage door. It thus involved the worm, worm wheel of 44 teeth, the final pinion and the rack.

 The octagonal windshaft, inclined at 10 degrees, has two square sections 10ft apart integrally cast for the head and tail wheels of a post mill. The present brake wheel is situated 5ft 2in behind the neck bearing and 9ft 3in forward of the tail bearing, measured on centres. The neck journal was formerly of the built-up iron and wood strip type, of 13in diameter, and similar to that described under Baker Street, Orsett, but was removed by Hector Stone in the late 1940s. Stone turned up the true neck of the windshaft by using a lathe bed fixed in position with blocks of wood and wedges, and applying wind power to the task, which took about two hours. The old bearing was replaced by a large roller bearing assembly costing £67, which may be seen today, though starved of grease and movement. It consists of two large rollers mounted in the box, which is 26in by 12½ in wide by 9in high and is bolted to a strong iron base plate 39in by 13in by 1½ in. It is the only such fitting known to have supported an Essex windshaft.

 The 10ft 4in thick brakewheel has six cants 15in at centre by 6½ in thick, with felloes 9in by 5in and 78 cogs of 5in face and 4½ in pitch. There are 8 iron T-section arms and a hub cast in halves and bolted together. The arms are 8½ in by 4in at centre and taper to 4in by 3½ in. This brakewheel exhibits several features of interest. It was formerly of compass-arm construction, indicating the use of a wooden windshaft. The 4in arm beds, central to the cants, have been blocked in, and there are no indications of a clasp-arm application, showing that the wheel was converted directly from primitive to modern, and probably at the time of introduction of an all-iron windshaft. The marriage of an octagonal iron spider to a hexagonal wooden rim leads to disharmonies such as the attachment of an arm at the narrow junction, 1ft wide, of two cants, and the possible use there of one only of the two bolt positions in the casting of that arm for fixing. The cants were made up of two layers of timber, breaking joint; the original cants of thickness 4½ in to which the felloes were attached, and what appear to be added plates, ¾in thick, on the forward (cog-tail) face. The latter give a wider braking surface. They terminate at the blocks filling the compass-arm beds, suggesting that they were fitted before the conversion from a compass-arm wheel.

 The brake is of six wooden segments of 8½ in by 3¼ in section, and its ends are left in heavier section and rounded where bolts pass through. When the braking surface on the wheel rim had worn down to within just under ½in of the cogs, it was lined with wood segments 9in wide by 1½ in thick, as now seen, the lining being held by screws with heads well embedded. This was commonly done after decades of wear to prolong the life of an expensive wheel. The brake lever is pivoted 2ft 9in forward of the brakewheel in a mortised vertical timber standing on the right sheer and held to the cap frame.

 The wooden upright shaft, 12-sided and 18in across the flats, is in two sections approximately 8ft 6in long above and 17ft 10in below, linked by a universal coupling 4ft on centre above the bin flooring. It is footed in a large bridging box with a two-screw control on each of its four sides to centre the internal pot which received the thrust, giving a fine and final control. The box is bolted to the elm sprattle beam, which is 8ft long by 17in wide by 14in deep, and wedged for coarse control against a pair of 10in by 9in horizontal timbers framed between the first-floor posts. The sprattle is aligned east-west and is 5ft 7in over first-(spout-) floor level. The shaft carries the wallower, the spur gear under the stone floor for underdrive, and a machine-drive gear 7ft above the stone floor. While a compass-arm spur wheel is not uncommonly seen in surviving English windmills, there are few such wallowers left, but at Upminster the all-wooden four-armed wallower of 5ft 4in diameter is still present. It has 43 cogs on a bevel. The arms, 11in deep by 3½ wide, were halved, inserted into mortices extending through a 20in length of the shaft, and wedged tight above and below. The 10ft spur wheel has six cants 15in across at centre and 3½ in deep, with felloes added to give a rim 8in wide by 7½ in deep. There are 126 cogs. All this very heavy load is carried by the elm sprattle.

 The machine drive, under the south side of the bin floor ceiling, was from an upwards-turned bevel gear of 3ft 10in overall diameter made in four solid wood segments built round the upright shaft, the drive being taken by a 16in wood-cogged bevel pinion on a short shaft carrying the sack-hoist pulley and also a 3ft 4in diameter massive wood pulley 12in wide, connected by belt to a line shaft on the west side of the stone floor. The pinion could be raised out of gear by a lever control inder the ceiling. The line shaft, running north-south, and 13ft 4in long, carries seven  iron pulleys, one of which received the drive, and the others drove various machines. An oat crusher was driven by a secondary shaft from the main countershaft.

 The wallower has a wooden friction ring built on underneath for sack-hoist operation, but at some date the bollard had been set lower, and it was further transferred c1948 to the third (bin) floor by Hector Stone. It had thus been fixed for operation on three different systems: by friction drive, by slack belt raising the bollard, and latterly by jockey pulley to tighten a slack belt.

 The great spur wheel drove four stone nuts of solid wood construction, 22in in diameter, each with 24 wooden cogs, and each put out of gear by twin screw jacks off a circular taper. The nuts consist of two wooden discs bolted together and having the cogs spiked through from above; they were little short of indestructible under normal use. The brake wheel, wallower, great spur and nuts were geared in the sequence 78-43 and 126-24, giving 9½ revolutions of the stones to one of the sails. The stones are centred 4ft 6in from the upright shaft.

 Four pairs of stones were wind-driven, but originally there were three, the change being made probably c1850. There are today three pairs of French burrs and one pair of peaks, the east and west pairs being 4ft 6in in diameter, the others 4ft. The disposition is east, west, north-east and north-west, the last being the peak stones. The south side of the mill is left clear for the sack traps; it has also the ladder wells in the south-east quarter, which are one above the other and, on the spout floor, ample space by the south exit door on to the stage for loading operations. Preserved in the mill is a sack-loading device resembling a wheelbarrow top; this was formerly hinged and chained at the stage edge opposite the south door for use with vehicles below.

 As the main stone-floor beams run north-south, the 12in wide by 6in deep bearers for the bedstones run east-west in all cases, the ones for the east and west stones being laid on the transoms at their outer ends and on the main floor beams at the inner ends. The full size of the bearers is everywhere preserved, the supporting timbers being slightly cut as necessary. 4in sq bridge pieces in pairs span the stone bearers to form framed squares on which lay the bedstones with packing, as required, to bring them level.

 A close examination of the great-spur stone nut relationship with the associated supporting framework allows the conjecture that the great spur gear is a successor to the original, that 3 pairs of wind-driven stones were originally fitted, as a sale notice implies, and that the first stone nuts were of larger diameter than the existing ones, as would be appropriate for cloth sails. The pine storey posts, or stanchions, supporting the stone-floor beams, are about 12in by 11in in section, and all have been cut away to lose about one-tenth of their section to allow the cogs of the great spur to pass. From old mortices and pivot holes, and the former position of the north stone bearers, it can be surmised that there were originally three brays between the stanchions pivoted on their south, east and south ends, for the west, north and east stones respectively, and carrying bridgetrees pivoted towards the sides of the mill in a manner similar to that used exceptionally at South Ockendon mill – probably built by the same millwright. Only on the east side of the spout floor is some indication still present – in a vacant housing and bolt holes, in the intermediate framing post – of a former bridgetree suspension post.

 It is possible that the earlier spur wheel also fouled the posts slightly, for there are two generations of cuts in the four posts. The earlier chamfers, formed with the precision of a more patient age, were later hacked away opposite the cogs of the existing wheel, which was probably introduced at the same time as the fourth pair of stones. The great spur wheel is built up with three straight arms 2¾ in by 10½ in deep, appearing as six spokes entering the mortices in the shaft. The arms would have been reduced at centre by about two-thirds of their depth to allow them to occupy the same plane. The first arm to be set in the shaft had an allowance of 2in above it for wedging, the second 4in, and the third 8in, all firmly blocked in after assembly. The shaft was also here packed out by 1in wood blocks, held by two iron bands, to reinforce the compass arms. Mitred fillets were applied at the junction of each arm with the enlarged shaft to give a trim finish. The ring of cants would have been fitted to the arms before their final wedging to the shaft; five have a tenon at one end and a mortice at the other for assembly in the “follow-round” design, but the sixth, at one end of the last arm to enter the shaft, appears to have a tenon at either end, perhaps to respond more positively to the final persuasive blows from the millwright. The wheel would clearly have been assembled off the shaft – and no doubt in the millwright’s workshop – prior to conveyance to the mill in its component parts.

 While a repositioning of the east and west stones would leave their bearers undisturbed, as the stones would simply be displaced along the bearers, the northern ones were brought, as a unit, 10½ in nearer the spur wheel, thus allowing a balanced positioning over them of the north-west and north-east stones, the empty housings so created in the floor beams being carefully blocked in. The modern scheme had no truck with brays, there being four sets of twin-ball governors, one for each pair of stones, driven from the stone spindles, and controlling the bridgetree ends direct: for the east and west stones at their north ends, and for the two shorter bridgetrees, placed in line on the north flank of the storey posts, at their outer ends. These two last are pivoted in a fifth and added post footed on a wooden plate spreading over two joists below, but having no further support for its double share of the runner stone weights overhead.

 The bridgetrees are suspended between elm hangers which each receive their entire support from two horizontal pine spacing blocks or horns on about 40in centres tenoned into them laterally from the stone floor beams above and the storey posts below. There are such vertical bridgetree supports, two each for the others. As examples, the south-west hanger is on 20in centres from the storey post, and those on the north side are set out 18in. This layout puts the stone centres, as stated, at 54in from the spur wheel centre; formerly the gearing ratio would have been considerably less, with the large diameter nuts making fewer turns for a given number of revolutions of the great spur. Judging from the earlier gearing diameters likely to have been used, the revolutions of stones to the former common sails could have been about 1:5. There is today a 6ft 3in head clearance beneath the bridgetrees, but in any case they run alongside the square of the storey posts, quite unobtrusively. On the north side the bins and a machine are placed under the two shorter bridgetrees.

 As in other late operating windmills, the machinery was carefully guarded to comply with the 1901 Factory Act, of note being the iron ring round the wallower and the metal sheeting which muzzled the fearsome bite of the cog jaws between wallower and brakewheel.

 Details of the last working sails at Upminster, which were double-shuttered anti-clockwise patents, were recorded by Denis Sanders in 1968, when they were taken down for replacement by Vincent Pargeter. The present sails were not intended to be exact replicas of the old.

 The last working middlings were 46ft long, 12in sq at centre, and continued thus for 5ft on either side, after which they tapered to 9in wide by 6in thick at the ends. The rear edges were relieved by 1¾in stopped chamfer starting at 2ft from the canister and running all the way to the tip, which was rounded by a curve of six in radius. The forward faces were left flat to receive the whips, which were bolted to them, giving an overall sail span of 70ft and a frame width of 7ft at the heel and 6ft 6in at the tip, indicating that they were slightly tapered. The whips, with small variations, were 33½ ft long, and tapered from 9in sq at their maximum section at the ends of the middlings to 6in sq at the outer extremities. They were also trimmed down on their rear faces, where bolted flat to the middlings, to a thickness of 7in at the heel; by this means the sails were dished. The whips projected about 12¼ ft beyond the middling.

 There were 36 leading and 36 driving all-wooden shutters on each sail, but the two pairs of sails differed in shutter size, one having only 35in by 8in shutters, and the other having leading shutters 26¾ in by 8in and driving shutters 39in by 8in. The last-mentioned had weights averaging 2 pounds 9 ounces and 3 pounds five ounces respectively, and the overall weight of all the 288 shutters would have been in the region of 870 pounds, a not inconsiderable addition to the weight of the middlings and whips combined, which, as a rough calculation shows, could have amounted to 1¾ tons. Assuming the use of timber weighing 35 pounds per cubic feet, and working from the dimensions above quoted, it appears that one of the middlings would have weighed approximately 1100 pounds and one whip 425 pounds.

 The middlings were of the shouldered type, having a 1in shoulder left on one of the side faces to abut the side of the canister, the timber being wedged in to hold it firm. The canister heads are about 25in long. Two pairs of oak clamps had been used to strengthen the middlings at centre. They were 16ft overall, and in one case measured 9in by 4in at centre reducing to 7in by 2in at the ends, near which were bolts passing from side to side to offset any tendency to split caused by the through-bolts mentioned below. As the canister has wrought-iron bands added for reinforcement at the ends of both boxes, it was necessary for the clamps to be cut away about an inch for accommodation, decreasing their effective thickness to an inadequate 3in in two rebates. The clamps were, of course, bolted together through the middling, there being three such bolt positions on either side of centre. Clamp and whip “overlapped” on the side and forward faces of the middling – by 5ft 4in in the example measured, and each whip was centrally attached.

 The sails had 12 bays between 13 sail bars mortised at varying angles through the whip, and also through the thimble bar provided on the trailing side and through the hemlaths on both sides. The following dimensions were taken from the pair of sails with shutters of unequal length. The innermost bar, at the heel of the sail, made an angle of about 23 degrees with the plane of the whip, this “weather” being less pronounced than on many. This angle diminished to almost zero at the tip. The heel bar was 5ft 3in from the inner end of the whip, which itself terminated about a foot from the canister. The bars were approximately 2½ in wide, but they were slightly tapered, and entered tapered mortices in the whips, thereby ensuring a good fit. Their thickness, in excess of 1½ in, was reduced to ¾ n to form the tenons in the hemlaths, projecting about 1in beyond. The whip was tapered on the drive side towards the tip in such a way that the thimble bar, placed against its trailing side face at the sail tip, diverged towards the heel, where it left a 3¾ in gap. This gap was closed by a piece of ½in thick boarding, tapered to suit, and nailed to the bars, with a decorative shaping at the heel. The thimble bar examined 3¼ in by 1¾ in, running in one length through the 12 bays, and carrying the thimbles on a pitch of 8¼ in. The thimble bar and hemlath on this trailing or driving side maintained a constant distance of 39 and 3/8 in clear between them, and this, in conjunction with the tapered fillet against the whip, explains the slight taper on the sail width to which reference has been made. On the leading side of the sail the thimbles were sunk directly into the whip, an awkward arrangement when it came to replacing damaged shutters, for the hemlaths opposite them had to be slackened off. The constant width of 27¼ in clear on the leading side between hemlath and whip face was maintained, despite the taper of the whip, by chamfering the side of the latter as necessary down to a line running close to the backs of the bars, which themselves projected through the chamfered face. The whip in each case was weathered or angled in sympathy with the angle of the bars in its outer face, with a clean-cut stopped chamfer point about 7in inwards from the first (outer) bar; this chamfer approximated to 5½ in wide.

 Back stays were fitted to alternate bars, making 7 stays in all on each sail frame. They were in heavy pitch pine, very well finished, and were tapered in both their sectional dimensions from 2 3/8 in to 2 1/8 in in width, and from 1 3/8 in to 1 1/8 in thickness. Their length was exactly 4ft, with in one example checked a 7¼ long land or housing at one end, terminating at a small shoulder, and a 3in long tapered land at the other. These took up the angles of the middling back and the outer end of a bar. Such complexity of work repeated in so many large and small component timbers underlines the enormous input of carpenter’s labour in the making of four such double-shuttered sails.

 The shutters were operated by an orthodox set of striking irons. On each sail iron U-pieces coupled the two shutter bars at two bays out from the heel, and were linked by a rod to the triangles and spider coupling, which was pushed out from the rear of the mill to close the shutters. The spider was linked by “rein irons” to the triangles, which were pivoted between “stump irons” standing on the whips.

 The steam engine formerly housed on the north side of the mill drove two pairs of stones independently of the windmill and situated outside it, but, through shafting, it was able to operate the line-shaft on the stone floor, used for powering machines. Sanders describes how the engine drove a 2½ in sq iron shaft 55ft long, coupled to an 8in wide wooden shaft 12ft long in the windmill base, and fitted with a ratchet device to prevent the sails from attempting to turn the engine. The engine was designed by Napiers, and had formerly been in use in a Thames steamboat. Wailes describes it as a grasshopper engine working in a 23in vacuum, and records its unauthorized removal from a “safe” depository.


Ruse’s Mill

Smock mill, gone


This low-built, self-effacing mill stood on a single-storied brick base on a low mound. A photograph of the massive wooden upright shaft, taken during demolition in 1955, shows an imposing inscription which may indicate the date of erection of the smock mill:




All four {sails} were double-shuttered, and each measured 8ft 2in and came within 2ft of the ground. The mill had three floors only. The machinery was predominantly wooden, including the windshaft, the nearly square upright shaft and the wallower; the brake and spur wheels had iron teeth segments attached. The two pairs of underdriven stones, on wooden bridgetrees and brays, were 4ft 2in for wheat and 4ft for barley, also powered by a portable steam engine which drove via a pulley and shaft to an all-iron extra rim added to the great spur gear. Mounted on the upright shaft was an unbevelled wheel with cogs on its lower face. This meshed with a spur gear on an all-wooden shaft for sack-hoist drive, the shaft being arranged to drop at its further end in order to tighten the belt (instead of the sack bollard being forced to rise). Another shaft with a wooden cogwheel was driven from the same downturned gear to drive an oat crusher on the first floor and a wooden countershaft on the ground floor.

 The mill had been topped in its later days by a shapely metalled ogee cap behind which the fantail drove to the iron rack. It had shuttered sails and vertical weatherboarding covering horizontal boarding.

Middleditch’s Mill

Smock mill, gone


Octagonal smock mill standing on a single-storied brick base. The mill had five floors, including the ground, and latterly had a gallery round the cap which James Wright, the last miller, had built himself. There was no stage. Two single-shuttered and two double-shuttered anti-clockwise sails had canvas on wooden frames, and these were operated by centrally-placed bars as at Radwinter smock mill. There was an 8-bladed fantail. The three pairs of stones last in use were 4ft 10in for wheat, 4ft 6in for barley and 3ft for splitting beans and peas, all underdriven from an iron windshaft and wallower in combination with a brakewheel and an upright shaft of wood. Two photographs of the mill show in the one case vertical weatherboarding and in the other horizontal, the latter probably in consequence of the removal of the former. The fantail was mounted close in at the expense of a surgical operation on the cap, a large section of which was cut away to give play to the blades.

Seward’s End

Post mill, gone


The roundhouse was built unusually close in, leaving half the brick piers exposed and giving the roof a very steep pitch. One pair of commons and one of double-shuttered sails were then in use; eventually all the sails were patents, struck from within the mill body. Winding was by tailpole. The weatherboarding at the front ran down at an angle from the corner posts to the prow, almost in herringbone pattern. There were two pairs of stones, arranged head and tail. Dibdin’s engraving of c1839 shows a wooden windshaft on the mill and another lying on the ground. Two side views of the mill, taken probably soon after 1900, show that the body had been extended to the rear at stone and “stage” (roof)-floor levels, probably to accommodate a flour dresser and striking tackle. External inclined wooden supports were evidently footed on the rear sill. The millers were assuredly not sun-seekers, as is indicated by the very small weather hatches and windows.