Publication Account
Date 2007
Event ID 587492
Category Descriptive Accounts
Type Publication Account
Permalink http://canmore.org.uk/event/587492
NF87 4 DUN TORCUILL ('Dun Torquil')
NF/889737
This unexcavated broch, probably ground-galleried, in North Uist stands on an islet in Loch an Duin, about 35m south-east of a promontory on the west shore; it is the best preserved example on both Uists and Benbecula (visited in 1971, 14/8/85 and 24/6/88). A broad stone causeway more than 1.8m (6 ft) wide runs in a shallow curve between the promontory and the island [4, fig. 107]; there are what look like sheep enclosures at the broch end of the causeway [4, 53]. The structure has been called a 'galleried dun' but the only reason for distinguishing it from a broch seems to be the slightly oval ground plan [5].
Description
Thomas' description [2] is fairly brief and he mentions only a “gallery or passage” in the wall about 76cm (2 ft 6 in) wide and interrupted by stairs in at least two places.
The building occupies almost the whole area of the islet, the wallfaces being festooned with lichen; the inner face stands nearly 2m above the rubble in places. The outer face has a slight batter and in 1914 it reached 2.7m (8.6 ft) in height on the north-west and 3.20m (10.5 ft) on the south [4]. The wall varies considerably in thickness, being 2.29m (7.5 ft) on the north and south-west sides, 3.05m (10.0 ft) on the east and 3.81m (12.5 ft) on the west-north-west; of course these thicknesses have been taken some distance above the primary floor level.
The dilapidated entrance is on the west-north-west but no door-frame can be seen at present; the width of the passage at the outer end is 1.14m (3.75 ft). A stretch of lintelled ground level gallery can be seen at about 9 o'clock on the northern arc and access into this is available by a gap in the lintels. One can thus determine that the gallery is 76cm (2.5 ft) at its floor and 60cm (2 ft) at its roof. There seems to have been an upper gallery on top of it; a short section of the inner wallface of the latter remains to a height of about 1.22m (4 ft). The top of the first flight of the intra-mural stair can be seen in the south-east arc, at about 1 o'clock, and the lintel of the doorway connecting this with the central court can be seen at about 12 o'clock, or about 3m anti-clockwise. A mural chamber is in the south-west, some 5.49m (18 ft) in length and 92cm (3 ft) in width.
Discussion
By contrast with Dun an Sticir a few more details of the architecture of Level 1 of this structure can be determined. A length of ground- level gallery is apparent, as well as a long intra-mural chamber, so one can probably conclude that the basal storey is mainly hollow-walled. The door to the intra-mural stair is exposed at 12 o'clock and the flight leads up into Level 2; the existence of the latter is confirmed by the fragment of an upper gallery. There are no signs of the other stair mentioned by Thomas.
The exactly elliptical shape of the inside wallface (below) is of considerable interest; the vast majority of brochs which have been surveyed to the necessary standard have precisely circular central courts. The dimensions of the ellipse (lengths of axes) at ground level could translate into 14 and 10 'megalithic yards' of 0.829m (Mackie 1977, fig.6) but this is implausible because too many fractions are needed to construct the ellipse. Yet the undoubted accuracy of the layout of the central court (not the outer wallface) surely gives us an insight into the nature of the community or family which commissioned the broch; ancient rituals involving precise measurement (and doubtless other things) were evidently involved in its planning and building and suggest that this broch was for a high-status group.
Dimensions [4]: internal diameter 11.59m (38 ft), wall thickness 2.39 - 3.81m (7.5 - 12.5 ft); the external diameter should therefore vary between about 16.17 to 18.91m (53-62 ft) and the average wall proportion seems to be about 33%, very low. In 1971 a new survey of the inner wallface (presumably above scarcement level) was made by the author and the inside wall of the broch, as noted, appears elliptical (it is surely significant that the places where the inner wallface leans inwards, and thus deviates from the elliptical shape, clearly show on the plan);
Allowing for 15sm for the width of the hidden scarcement it is striking how an ellipse based on a 5:12:13 Pythagorean triangle and with long and short axes of 39 and 36 Greek feet (of 12.15in or 30.86cm) fits the inner face as exactly as seems possible uner the circumstances. The author hopes to publish a paper on this topic, titled “Ritual and measurement among Scottish Iron Age elites: evidence from four elliptical brochs in the west”.
Sources: 1. NMRS site no. NF 87 SE 3: 2. Thomas 1890, 402: 3. Beveridge 2001, 149-52: 4. RCAHMS 1928, 52-3, no. 172: 5. Feachem 1963, 183: 6. Armit 1996, 9: 7. Armit 2002, 22.
E W MacKie 2007
