Aironn Mill

The ruin of this corn-mill is situated on the W side of the valley of the Abhainn Mhor, some 300m N of the small 19th century crofting settlement of Aironn, which stands near a sheltered bay on the NW shore of Loch Caolisport. Although commonly known as 'Stronefield Mill', from the deserted settlement of that name situated 0.8km further up the valley (NR 720748), the mill belonged to the township of Balimore, and a footpath connects it to the remaining buildings of that farm, 0.7km to the W (NR 708740). The hearth-tax schedule of 1693 records 'ane miln' at Balimore, which was part of the Knap estate, and the Military Survey of about 1750 names the site 'Mill of Knap’ (1). The existing building probably dates from the last quarter of the 18th century, when the Knap estate was acquired by the Campbell family of Inverneill. In 1869 it was reported that the mill was 'now disused and going into ruins' (2).

The water-supply was secured by damming an extensive marshy area drained by a stream, about 25m above the level of the mill, which was shown by the Military Survey as a lake. The turf-and-stone dam, about 100m NW of the mill, incorporates a horizontally-placed slab with an 0.25m central aperture into which a bung could be fixed to control the flow of water into the lade (3). The lower course of the lade was excavated into the steep hillside behind the mill, but no remains of any artificial revetment are identifiable. It ran close to the natural watercourse and an overflow-channel into this stream was formed 5m NW of the mill. The building was gabled and two-storeyed, and measures 10.8m from E to W by 6.4m over walls 0.7m in general thickness but increasing to 0.9m at the SW end, which housed the machinery. Its masonry is of lime-mortared rubble, varying in size but with some substantial roughly-squared blocks in the outer faces, and large slab quoins. A few slates from the former roof are still visible.

In the original arrangement there was a wide segmental-arched loading-door in the NE gable. Subsequently this was blocked by the construction in the N angle of a drying-kiln 3.2m square. The only remaining entrance is a ground-floor doorway in the SE wall, O.95m in width, which leads into a passage formed by the kiln. The ground floor was lit by windows near the centre of both side-walls, and a low-level opening towards the SW end of the SE wall lit the gear-cupboard. An upper window above this one served the stones-floor, but there is no evidence of windows or doors in the loft in the NE end. Surviving joist-sockets in the sidewalls show that the level of this half of the upper floor was about 0.7m above that of the stones-floor, and subsequently it was encroached on by the kiln. Indeed it is possible that the area above the entrance-passage was not floored, allowing space for a sack-hoist, since no floor-sockets were built in the SE face of the kiln. Access to the upper floor was presumably by an'internal timber stair.

Outside the SW gable-wall a wheel-pit 0.7m in width has been formed by a neatly-built mortared wall, battered on the outer faces and connected to the mill by a slab bridging the tail-race. At its upper end a series of schist slabs has been shaped to the curve of a former water-wheel about 3.8m in diameter. A narrow ledge at this end of the lade may have carried a support for the flume, but no sockets for it are identifiable in the end-wall of the mill. It is probable that the wheel was of high breast-shot construction, with the flume carried at about eaves-level. The wheel-axle entered the mill by an opening 0.75m square, whose sill and lintel are perforated by sockets respectively 0.13m and 0.17m in diameter. Both of these slabs are probably re-used millstones, but the sockets are aligned and may have carried an axle-bearing. To the SE of this opening there is a socket, on the probable line of the rim of the wheel, which may have held a brake, and at a higher level there is a recess to allow inspection and repair of the inner rim of the wheel. Inside the building, the stones-floor was supported by a framework of heavy timbers fitted into two vertical chases in the end-wall, and into sockets at two levels in the side-walls. A low cross-wall forms a gear-pit 0.9m in width. A pair of schist stones, each 1.37m in diameter and having a 0.24m central aperture, lies on the floor of the mill, and outside the SE door there is a single lower stone, 1.42m in diameter and having a 0.l6m aperture within a shallow recess 0.21m square. A partially-quarried stone of much smaller dimensions, perhaps intended for an earlier mill on this site, has been recorded at Cnoc nan Sionnach, 650m to the NW (No. 232).

The masonry of the kiln is similar to that of the original building. In its SE wall there is a stokehole 0.79m wide opening into the lower chamber, which was lined with bevelled masonry to form an inverted pyramid but is now blocked with loose soil and rubble. The upper floor was spanned by joists utilising the existing sockets in the NW wall of the mill. It was entered by a door in the SW wall, and in the S angle there is what appears to be a chute for the dried grain, having an outlet opposite the entrance-doorway of the mill.

In a Knap estate-rental of 1789, Archibald MacCallum was recorded as paying £9. Is. 6d. for the 'miln and acre', and earlier reports listed the 'souming', or total livestock and sowing allowed on the land attached to the mill (4*). The miller's dwelling of this period is probably represented by the footings of a rectangular building situated 8m E of the track that passes the mill, at the edge of an area of level ground extending to the Abhainn Mh6r. It measured 12m from NE to SW by about 5.5m, and a cross-wall appears to have formed a small compartment in the NE end, with its own entrance-doorway, but few details of the layout are identifiable. Curving drystone walls abutting the side-walls of the dwelling form a small enclosure between it and the adjacent stream. A stone-lined spring has been cut into the rocky slope only 3m from the N angle of the mill, and its overflow is channelled into a drain beside the track.

RCAHMS 1992, visited May 1985

RCAHMS surveyed Aironn Mill on 16 May 1985 producing a site plan at a scale of 1:400 and ground and first floor plans at a scale of 1:100. The site plan and floor plans were redrawn in ink and published at scales of 1:1000 and 1:250 respectively (RCAHMS 1992, 479A-B).