Water-powered corn mill, 1767 by John Smeaton, extended to east and north by 1775 and subsequently raised in height.
Reason for Listing
This water-powered corn mill of later C18 by John Smeaton, extended by 1775 and subsequently raised in height, is listed at Grade II* for the following principal reasons:* Date: as a later C18 corn mill, the building sits firmly in the period when there is a presumption in favour of listing; * Historic interest: it is considered to be the only extant water-mill designed by the eminent C18 engineer John Smeaton; * Intactness: although extended, Smeaton's original corn mill retains its integrity and is readable; the extended building retains its C18 footprint and interventions are relatively minor in nature or do not detract from its overall interest; * Architecture and process: it is a good example of a relatively small scale later-C18 water-driven corn mill constructed to supply a local market, whose form visibly illustrates its former industrial function; * Machinery: the almost complete 1817 cast-iron and timber water wheel of genuine pitchback design with associated features is a fine example of extreme interest; *Documentary evidence: original drawings of the mill survive.
In the mid 1760s, Greenwich Hospital Estates required a new manorial corn mill in Alston, and engaged as designer one of their managing agents, the eminent engineer John Smeaton. High Mill was designed in c. 1767 and original drawings for the mill and machinery survive: the wheel was 30 feet in diameter and 10 inches wide and had a unique backward curved scoop feed, fed by overhead wooden troughs; Smeaton had worked out that this avoided the drag effect in discharge of the buckets to the tailrace. The mill was one of three mills driven from a large race into which water was channelled from a dam at High Fairhill; sub-ground channels beneath the town channelled the mill race and the spent water ran into an outlet and rejoined the main race. In 1775 the mill is described in a report as three pairs of stones, machinery for shelling oats, and oat mill and drying kiln, and the same year it was let to Adam Wilkinson & Co for £30 a year. John Smeaton (1724-92) was an eminent C18 engineer, perhaps best known for rebuilding the Eddystone Lighthouse. As his Oxford Dictionary of National Biography (ODNB) attests, he is highly regarded and is considered to have had a career of extraordinary distinction and breadth, producing a series of designs and plans unrivalled in clarity and logic; his works ranged from mills (water and wind) and steam engines to bridges, harbours, river navigations, canals, and fen drainage, in addition to major contributions to engineering science. he is considered the greatest authority of his time on mill works. Between 1764 and 1767, Smeaton was employed as one of two Greenwich Hospital agents or 'Receivers' and helped to improve many of the mills on the estates. Differences in the stonework of the present building show clearly the outline of Smeaton’s original mill, and that it was subsequently extended to the east and the rear; a map of the town of Alston by Fryer and Hilton dated to 1775, depicts the footprint of the mill with the eastern and rear extensions clearly shown, thus illustrating that the building had already been extended by this date. In 1817 a report describes the mill as ‘a large old wheat and flour mill, three storeys, with two pairs of millstones, a dressing machine and a stable under the same roof'. The mill required repair however, and later in 1817 a new water wheel, 21 foot in diameter, and of similar pitchback design, replaced the original; the original overhead water supply was also removed and water feed was restored by underground pipe and riser. The lease changed hands often after the mill was refurbished but in 1851 the miller was Robert Nattrass who employed four men. During the 1850s, documents record the installation of a steam engine, removed soon after as it proved unsuccessful. The last major extension to the building probably occurred in the later C19 when it was raised by the addition of a fourth storey and re-roofed. In 1947 after the mill had ceased to function, the building was purchased and used as the administrative headquarters of a precision foundry (Precision Products (Cumberland)) and it was linked via a pair of aerial walkways to newly-built workshops. The foundry produced coal mining drill bits (and subsequently precision cast golf club heads) using the Shaw Process, a ceramic mould casting process developed by Noel Shaw, who had been involved with early precision cast turbine blades for Frank Whittle's jet engines. The workshops were subsequently used to make preform moulds for a new casting process, ECOSHAW. In 1992 the North Pennines Heritage Trust carried out repairs to the mill including roof repairs, conservation of the wheel and the installation of a public viewing platform.
Water-powered corn mill, 1767 by John Smeaton, extended to east and north by 1775 and subsequently raised in height. MATERIALS: coursed rubble sandstone with dressed sandstone quoins; welsh slate and stone slate roofs.PLAN: the four-bay mill building is oriented roughly east to west and occupies a site that slopes down from south to north and more gently from west to east. The westernmost three bays comprise the original, rectangular, C18 mill with a semi-basement cart entrance in bay three on the south elevation. A slightly projecting, enclosed, rectangular wheel house is attached to the west gable of the mill building with water wheel and associated features. The easternmost bay and the rear extension are additions creating an overall L-shaped plan. EXTERIORMILL BUILDINGSouth elevation: comprising four bays and four storeys under a hipped roof of slate; clearly visible differences in stonework indicate that the building consists of three phases. Phase one comprises bays one to three to the top of the second floor, and is John Smeaton’s original three bay, three-storey mill with prominent quoins and a wide, segmental-arched cart entrance to bay three. There are paired windows to the ground and first floors; the left hand window of the latter has a crude stone lintel and is probably an original opening, and a single second floor window occupies the position of a window on Smeaton’s original plans. Where visible, all window openings are fitted with C20 timber casements. In phase two the mill was extended to the right by the addition of a fourth bay; this has paired window openings to the ground, first and second floors. First-floor windows are fitted with C20 cross frames and others are mostly C20 casements. The third phase of the building involved the raising of the roof to create a fourth attic storey across the full width of the building, pierced by three regularly spaced windows. East gable: this has a central, ground-floor entrance with stone lintel and jambs flanked by small square openings blocked with stone and brick. A covered aerial walkway links the building to surrounding C20 foundry workshops. Rear elevation: the visible part of the rear elevation contains a mixture of openings including one ground floor window with stone lintel and jambs, now blocked. Other openings comprise windows and taking-in doors at various levels all fitted with C20 frames and doors; a second aerial walkway links the building to surrounding C20 foundry workshops. A three-storey lean-to extension obscures all of Smeaton’s original rear elevation; this has a stone slate roof, a central chimney, a pair of upper windows and a large C20 inserted window, all of the latter fitted with C20 frames. The lower eastern end of the extension has a number of early blocked openings including a narrow door opening with a stone lintel and jambs, blocked with brick in its upper parts and stone below. Attached to the east is the slightly projecting rear wall of the wheel house, its upper parts rebuilt in brick. The west end of the extension has a double ground floor entrance with tall taking-in doors above (the left side shoulder-arched); there is a casement window above and the fourth floor has a second set of taking-in doors, all fitted with C20 window frames and doors. WHEEL HOUSE: an original single-storey wheel house is attached to the west end of the mill; it projects slightly forward and has a steeply pitched roof of slate and a single entrance with stone lintel and jambs. INTERIOR
MILL BUILDING: all floors (except the later attic floor) retain the original divisions between the original mill building and the extensions to the east and the rear. On all floors the original single mill space has been subdivided by insubstantial C20 partitions to create an enclosed C20 stair. The first floor of the original mill building, adjacent to the party wall with the wheel house, retains a second wheel pit housing a large timber and iron cogged wheel forming part of the gearing system; the blocked, round-headed opening through to the wheel house is also visible, as is a narrow rectangular slot in the wall above. The first and second floors of the original mill both retain partial timber floors and each has a large square hatch with iron hinges. The accessible part of the ground floor rear extension retains a rectangular space with an alcove at its west end, and there is a further space to the west about eight feet square, formerly accessed by a door (now blocked) in the rear wall of the extension; this space is considered to have been sealed off for some time and it is possible that original machinery may exist within. The attic floor is undivided and has a floorboard floor; its roof structure is formed of four triangular trusses which appear to be later replacements, although one member is a re-used beam.
WHEEL HOUSE: the former presence of the original, larger wheel is indicated by rim markings low down at the north end of the east wall, and there is a low-level doorway in the same wall that corresponds to an external exit on Smeaton's drawings, now blocked by the northwards extension of the mill. There is a further blocked off space about sixteen feet square beyond the pit wheel at the back of the main wheel in the wheelhouse. Against the east wall there is also a deep, wide, stone-lined wheel pit. This contains a 21 foot diameter and 26 inches wide water wheel of pitch back design; its hub and rim are of cast iron, the latter with timber-slatted underside and has wooden spokes and c. sixty wooden buckets. To the rear of the wheel is a suspended timber-slatted diversion channel and part of the tail race culvert. The axle passes through an carefully detailed round-arched opening in the east wall, now blocked with brick. The timber box or spreader, which contained the water feed and controls and provided a smooth supply of water to the wheel, remains in place above the wheel on a frame of timber supports; a tall cast-iron stand pipe, which formerly fed the wheel with water, stands to the west of the wheel.
Listed building text is © Crown Copyright. Reproduced under licence.