Report of excavation in 1972 by Prof A.S.Robertson and Dr J.Mackenzie
The full text of this report can be found in A.S.Robertson “Roman ‘Signal Stations’ on the Gask Ridge”, Transactions of the Perthshire Society of Natural Science (Archaeological Section), Special Issue, 1974.
In 1972, opportunity offered itself of conducting a small-scale excavation at Roundlaw, since the field in which it stood was in that year under pasture. The week’s work was directed by Dr John Mackenzie, University of Lancaster, and myself, with help from Miss Kay Docherty (Hunterian Museum), Miss Gillian Gibson (St.Andrews University), Graham Magauran, M.A. (Glasgow University), Gordon Thomas (Edinburgh University) and members of the Archaeological Section of the Perthshire Society of Natural Science and of the Strathearn Archaeological Society.
The Air photograph supplied by Dr St. Joseph showed a circular ditch with an opening to the south, and apparently four post-holes inside. There are no surface indications whatsoever. The first trench laid out was sited a little too far west, since the “signal station” proved to have stood a little way down the slight eastern slope of a small hump, instead of on the highest part of it.
Trench 2, however, 84′ (25.7m) long and 4′ (1.22m) wide, soon revealed the west ditch and, as it progressed, the east ditch of the “signal station.” The site was of solid rock, and since the excavation followed several weeks of drought, the digging of this “signal station” was the hardest physical work yet required on the Gask ridge.
The reward came with the clearing out of the ditches in Trench 2. They were not the conventional V shaped ditches, but were of the “Punic” type, that is, there was an almost vertical drop on the outer side, or counterscarp, while the inner side or scarp sloped gently upwards from a narrow, flat bottom. The ditches sectioned in Trench 2 were 7′ (2.13m) wide, and had been hacked down to a depth of over 4′ (1.22m) into the solid rock.
The west and east ditches located in Trench 2 were 47.5′ (14.5m) apart, and in the space between them there was no sign of a bank in situ. The rock surface was only about 8″ (.20m) under the surface, and the plough in its work over the centuries must have skimmed off the upper part of any bank that had been present.
The nature of the bank was, however, made clear by material in the east ditch. There was natural silting in the bottom to a maximum depth of 2′ (.61m), and above that fallen turf which had evidently slipped into the ditch from a bank to the west of it. The west ditch in Trench 2 contained no turf slip, only natural silting. The reason for this was the slight slope in the ground from west to east, which allowed material to slip eastwards, but not westwards.
The use of turf for the bank of Roundlaw “signal station” was made necessary by the unsuitable nature of the material dug out of the solid rock in making the ditch. This material must have been in the form of rubble and small stones, which would make a very unsatisfactory, unstable bank. The bank must either have had turf cheeks retaining a central core of rubble, or else have been formed entirely of turf stripped from the surrounding area.
The perimeter of the encircling ditch was further determined in Trench 3, to the north-east of Trench 2. A well-preserved “Punic” ditch-section was again revealed, with the expected width, 7′ (2.13m) and depth, 4′ (1.22m). Natural silting filled the lower 2′ (.61m) of the ditch, and above that there was fallen turf, and earth with flecks of turf, the latter from wash-down into the ditch.
The interruption in the south side of the ditch for a causeway was located in Trenches 4 and 6. The sharp “Punic” outline was perfectly preserved quite close to the ditch-end on the east side of the causeway and there were turf flecks in the dark earth silting of both ditch-ends. The causeway was only 6′ (1.83m) wide.
No post-holes were present in the main long trench (T2), but three were found in Trench 5, south-east of Trench 2, and two others in two small squares (T7 and T8) cut on the north side of Trench 2. Yet another trench (T9) just missed a fourth post-hole which must have been located beyond its southern edge.
Since they had been chipped out of solid rock, the post-holes were not of the conventional round shape, but had very jagged edges. They were all about 2′ (.61m) across, and probably 2′ (.61m) deep.
The wooden tower whose four corners were marked by the post-holes seems to have been 10′ (3.05m) wide from east to west, and as much as 14′ (4.27m) long from north to south, measuring from centre to centre of the post-holes. The tower in that case stood much closer to the south ditch (i.e. on the causeway side), the distance being about 14′ (4.27m) than to the north, east and west ditches, the distance in these cases being about 17′ (5.18m). No evidence was recovered for the width of the encircling bank, but it may have been about 9′ (2.74m) wide, as at Gask House and Parkneuk.
Roundlaw “signal station” faced south over Strathearn. It stood about 140′-l50′ (42-46m) north of the Roman road. Presumably its southward link was with Ardoch, or with other stations on the Roman road running south from Strageath past Kaims Castle to Ardoch.
The only finds from Parkneuk were a few tiny flake and quartz chips, wood scraps and iron nails. The two last came from the two northern post-holes.