Publication Account

Date 2002

Event ID 585696

Category Descriptive Accounts

Type Publication Account

Permalink http://canmore.org.uk/event/585696

Euan W Mackie Broch Corpus 1

HY52 1 BURROUGHSTON ('Hillock of Burroughstone', 'Borrowstone')

HY/54042100

A solid-based broch on Shapinsay standing at the foot of a gently sloping field just above the low rocky beach. The grass-grown structure may be on a platform, and is surrounded by a huge ditch. In about 1862 a Mr. Balfour of Balfour and Trenabie got some men to open up the mound “shortly after the discovery of Maes Howe” and George Petrie made notes on the structures exposed while Sir H. Dryden made a plan of them. Very little can now be seen of broch in general from the outside since little of the outer wall was exposed during the excavations; the building appears now as a grassy mound.

The entrance passage is still visible with a little of the outer wall face on either side of it; it faces east and is about 3.7 - 4.0 m (12-13 ft.) long, 1.2 m (4 ft.) wide and 1.8 m (6 ft.) high. It now has one massive lintel at the outer end (the others having been snapped off), and in 1862 this was described as three close-set together on edge; they must have supported the outer wall face. The doorway below the lintel is now blocked u The underside of the surviving lintel presumably gives the height of the remainder, and it can thus be seen that the south side of the passage extends for at least 1.5 m above this level; it must therefore be the side of the chamber above the entrance.

Two door-frames are still apparent, some 2.5 m (8 ft. 1 in.) and 2.2 m (7 ft. 2 in.) from the outer end of the passage according to Dryden's plan; thus they are not quite opposite one another. The one on the left (looking in) is made from a projecting slab, and the other is a built check. Behind the left (S) check is the bar-socket and the hole can be seen opposite it. There is an elongated guard chamber opening from the left side of the passage (looking in), the door being only 41 cm (1 ft. 8 in.) wide. This cell is 4.4 m (14.5 ft.) long and about 2.4 m (8 ft.) high at its outer end; it diminishes gradually in height (to 1.14 m or 3 ft. 9 in.) and in width towards its inner end. The chamber is roofed with flat lintels which probably means that there is an upper gallery immediately above it. There is an ingenious slot leading from this chamber to the entrance passage in front of the door-checks; a ranging pole can be poked through this, so presumably a spear could in Iron Age times.

According to Petrie the average internal diameter of the broch is 10.2 m (33.5 ft.) and the wall apparently varies in thickness from 4.3 m (14 ft.) down to 3.05 m (10 ft.) or less [2]. Petrie actually describes it as thick at the entrance and on the opposite side, being thinner elsewhere, so he may have been mislead by a thinner wall head thickness in places. The wall was later measured as 3.7 - 4.0 m thick (12-13 ft.) near the entrance [3]. The inner face stood to a maximum height of 3.7 m (12 ft.) on the east and west in 1928 [3] but Petrie recorded it as 4.0 - 4.3 m (13-14 ft.) [2, 81]. On this face is a scarcement ledge 2.7 m (9 ft.) which was above the floor in 1928 [3] and 3.1 - 3.4 m (10-11 ft.) in Petrie’s day [2]: it is not much more than 2.5 m above the interior ground level now. The scarcement is of the “shelf” type and Petrie records it as 45 cm (18 in.) wide.

Petrie records two openings 1.1 cm (3.5 ft.) wide in the inner wall face nearly level with the scarcement, one at 12 o'clock and the other at 9 o'clock [2, 82]. Dryden's drawing shows one of these raised voids with its sill at scarcement level [2, fig. 12: 3, fig. 363], and he also shows a section through the raised mural gallery (which looks rather low) on the same level, resting on a wallbase which seems to be solid up to that point. However he also shows a section of what looks like a very low gallery at ground level, also at 9 o'clock, but nothing is indicated here on the plan; it is in fact the misplaced cross-section of the inner end of the guard chamber, which ends at about 7.30 o'clock. The upper gallery is recorded as 84 cm (2 ft. 8-9 in.) wide. There were also traces of “two ascending steps” in the gallery at one point, and “three at another” [2, 82]. No proper mural stair is described, and no door to it from ground level is shown. It may well not have been discovered behind the secondary constructions (below).

At present the outer face of the upper gallery is clearly visible from about 9.30 - 11 o'clock, with one lintel still in position. Traces of the opening to the upper gallery from the interior are still apparent at 9 o'clock, but the one at 12 o'clock is hidden or destroyed. The inner face of the upper gallery runs anti-clockwise towards the entrance from the first void.

Secondary constructions with radial partitions were found in the broch interior. Though Dryden's plan and elevation are not altogether clear, the section seems to show some form of incomplete aisled wheelhouse-like structure with radial piers joined by lintels to a secondary wall constructed against the inner face of the broch wall on the arc from 6-9 o'clock. At one point a solid block of masonry appears to project and lie against one of the radial stone slabs; on its other side it is shaped like an alcove, rather similar to the structure at Midhowe (HY/33 1); this was roofed with lintels when found, and the elevation shows this [2, fig. 12].

A deep well was in the broch floor, appearing like a vertical shaft in Dryden's section: the upper part was of dry stone masonry, the lower cut into the rock. An extension outwards to the main entrance -- evidently with door-checks of its own -- was built at one point for about 3.66 m (12 ft.) and led to an “oblong building” [2].

An outer wall was found to be concentric with the broch on the W, and about 2.74 m (9 ft.) from it. Beyond this was a broad ditch from 4.9 - 5.5 m (16-18 ft.) wide at the base with an earth bank or parapet beyond this, 76 - 92 cm (2.5 - 3 ft.) high in places.. Only on the seaward side are defences lacking, and here traces of outbuildings were found. The inner wall stood 1.8 or 2.1 m (6 or 7 ft.) above the bottom of the ditch outside it.

Dimensions. The external diameter has to be estimated as the wall thickness of 3.7 - 4.0 m (12-13 ft.) is apparent now only at the entrance. Taking the internal diameter as 10.21 m (33.5 ft.), the external diameter should be about 17.7 - 18.0 m (58-59 ft.) and the wall proportion 42.5%. New measurements of the interior wallface in 1985 by the writer showed that the broch was probably intended to be built round a true circle with a radius of 4.82 +/- 0.12 m, equivalent to a diameter of 9.64 m (31.61 ft.).

Finds. Little information was available about these but a list is now available [4]. According to Petrie they were mostly deer-horn fragments, many ox and sheep bones and "several rude stone vessels of different sizes", including a possible triangular lamp Only a bone or antler 'perforated mount' now survives [4, 122]. A stone lamp from 'Shapinsay' in the Hunterian Museum could be from this broch (B.1914.829).

Sources: 1. OS card HY 52 SW 4: 2. Petrie 1890, 81-4 and 87: 3. RCAHMS 1946, 3, 275-76, no. 778 and figs. 362 and 363: 4. Hedges et al. 1987, 122-24 and pls. 3.16-3.20 (ms plans (two), panoramas (two) of interior, and general plan of broch and outer wall, by Dryden): 5. Lamb 1987, 11.

E W MacKie 2002