High Mill

High Mill

Water-powered corn mill designed by John Smeaton in 1767, extended to the east and north by 1775 and subsequently raised in height. The building is constructed of coursed rubble sandstone with dressed sandstone quoins, and is roofed in Welsh slate and stone slate.

The mill building comprises four bays oriented roughly east to west on a sloping site that descends from south to north and more gently from west to east. The westernmost three bays form Smeaton's original rectangular three-storey mill, with a semi-basement cart entrance in the third bay on the south elevation. A slightly projecting enclosed rectangular wheel house is attached to the west gable. The fourth bay and rear extension are later additions, creating an overall L-shaped plan.

South elevation: This comprises four bays and four storeys under a hipped roof. Three distinct construction phases are evident in the stonework. The original three-bay, three-storey mill (Smeaton's work) extends through the first three bays to the top of the second floor, marked by prominent quoins and a wide segmental-arched cart entrance to the third bay. Paired windows occur at ground and first-floor levels; the left-hand first-floor window retains a crude stone lintel and is probably an original opening, while a single second-floor window aligns with Smeaton's original plans. All visible window openings are fitted with twentieth-century timber casements. The second phase of construction added a fourth bay with paired window openings to the ground, first and second floors, fitted with twentieth-century cross frames and casements. The third phase raised the roof to create a fourth attic storey across the full width, pierced by three regularly spaced windows.

East gable: A central ground-floor entrance with stone lintel and jambs is flanked by small square openings blocked with stone and brick. A covered aerial walkway links the building to surrounding twentieth-century foundry workshops.

Rear elevation: The visible part contains a mixture of openings including a ground-floor window with stone lintel and jambs, now blocked, along with windows and taking-in doors at various levels fitted with twentieth-century frames and doors. A second aerial walkway links to surrounding twentieth-century foundry workshops. A three-storey lean-to extension obscures Smeaton's original rear elevation, with a stone slate roof, central chimney, a pair of upper windows, and a large twentieth-century inserted window all fitted with twentieth-century frames. The lower eastern end of the extension contains several early blocked openings, including a narrow door with stone lintel and jambs, blocked with brick in its upper parts and stone below. The wheel house's rear wall is attached to the east, its upper parts rebuilt in brick. The west end of the extension features a double ground-floor entrance with tall taking-in doors above (the left side shoulder-arched), a casement window above, and a second set of taking-in doors on the fourth floor, all fitted with twentieth-century frames and doors.

Wheel house: An original single-storey structure attached to the west end of the mill, projecting slightly forward, with a steeply pitched slate roof and a single entrance with stone lintel and jambs.

Interior

Mill building: All floors except the later attic retain original divisions between the original mill and the eastern and rear extensions. On all floors, the original single mill space has been subdivided by insubstantial twentieth-century partitions to create an enclosed twentieth-century stair. The first floor of the original mill, 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. A blocked round-headed opening through to the wheel house is 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 a further space about eight feet square formerly accessed by a now-blocked door in the rear wall; this space has apparently been sealed for some time and may contain original machinery. The attic floor is undivided with a floorboard floor; its roof structure comprises four triangular trusses that appear to be later replacements, although one member is a re-used beam.

Wheel house: Rim markings low down at the north end of the east wall indicate the former presence of an original larger wheel. A low-level doorway in the same wall corresponds to an external exit shown on Smeaton's drawings, now blocked by the northwards extension of the mill. A further blocked space about sixteen feet square lies beyond the pit wheel at the back of the main wheel. A deep, wide, stone-lined wheel pit built against the east wall contains a water wheel of 21 feet diameter and 26 inches wide of pitch-back design. Its hub and rim are of cast iron, the latter with timber-slatted underside, wooden spokes, and approximately sixty wooden buckets. Behind the wheel is a suspended timber-slatted diversion channel and part of the tail race culvert. The axle passes through a 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.