Links between stone rows, banks and stone circles - BODMIN MOOR

Craddock Moor (South East Bodmin Moor)

The area northwest of the village of Minions is extraordinary for those who enjoy prehistory. Within an area just 2km by 2km there are two Tor enclosures (Stowe Pound and Treggarrick Tor), four stone circles (three known as The Hurlers plus Craddock Moor circle), two stone rows (Minions and Craddock Moor) and several barrows. The Rillaton Barrow is the largest (34m diameter, up to 2.7m high) and is visible from Dartmoor. A secondary burial in it yielded a fine Bronze Age gold cup which is now on display in the British Museum.

There is also a curious arrangement of parallel banks, thought to be prehistoric (see HER list entry 1009840). Two banks, each about 3m wide and 6m apart, run roughly SE for about 90m and then turn to head ENE for about 35m. The banks aren’t continuous in that they have gaps. It could be argued that they are cairn alignments, but the cairns are rectangular in plan rather than circular. The arrangement can also be interpreted as two lines of parallel banks intercepting each other, rather than one line that changes direction.

The geometrical arrangement of Craddock row, two of the circles and the banks strongly suggest to us that, at least at this location, the stone circles were designed to work in tandem with the stone row, and /or the row was designed to work with the stone circles. The map below explains why:.

It is clear that:

·        The north end of the row, the longer section of the parallel banks, the centre of the Craddock Moor circle, and the centre of the Hurlers South circle, are all precisely on one line. The line runs parallel to and between the parallel banks.

·        The Craddock Row is set exactly at 90 degrees to this line.

·        If the shorter section of banks is extended, the line meets the south end of Craddock Moor row, thereby completing a right-angle triangle.

·        If we extend the hypotenuse line to the northeast, it reaches the Merrivale stone row complex on Dartmoor. Furthermore, the line either runs down the west section of Merrivale 1 or is remarkably close to doing so.

It seems we are starting to see a design that involves a Bodmin Moor row, a Dartmoor row and two circles on Bodmin Moor.

There are several surveying sequences which could explain this arrangement. We examined several before we noticed that if you extend the north east side of the triangle eastwards for 26km it runs along a ridge at Whitleigh, just north of Plymouth. Furthermore, a line at right angles from Whitleigh takes you to Merrivale, plausibly arriving along the Merrivale 3 row.

INTERPRETATION

Let’s label the smaller triangle’s apexes as N, S and B which are at the North end of Craddock Moor row, the South end of the row and at the Banks intercept, respectively.

We will label the larger triangle apexes BMW i.e. Banks intercept – Merrivale – Whitleigh ridge.

NSB is on Bodmin Moor whilst the much larger BMW spans the low land between Bodmin Moor and Dartmoor. The two triangles are similar in that they share the same angles. Intriguingly, the larger triangle is exactly 70 times the size of the smaller one.

We noted that the surveyors seemed sufficiently confident of the accuracy of their line NBW that two circles are on it, and they probably set Craddock Moor row to be at 90 degrees from it. Also, the Craddock Moor banks are very unusual which is consistent with exceptional care being taken at their location. All the remains are consistent with line NBW being set early in the Bodmin survey, and other lines then being extended from it.

We suggest that a plausible interpretation is that:

1.      Merrivale had been fixed by surveyors on Dartmoor.

2.      They saw an opportunity in the flat area of Craddock Moor and the ridge at Witleigh to set geometry which would a) set new survey lines on Bodmin Moor b) anchor that survey to the Dartmoor survey oor and c) determine the distance of Bodmin Moor from Dartmoor.

3.      They set the line MW and fixed the location of W from Dartmoor.

4.      They set a line at 90 degrees to MW. The line went along the short Witleigh ridge which may have enabled lights to be lit to aid alignment from Bodmin Moor.

5.      The line arriving on Bodmin Moor was extended to include BN.

6.      They set a line at 90 degrees to WBN at N, setting stones southwards i.e. forming Craddock Moor row.

7.      The continued the row until its length NS was 1/70 of MW.

8.      They took a line from S to Merrivale. They laid row section Merrivale 1 West to assist the alignment of M and S, perhaps also aided by a light at S.

9.      The intercept at B was set carefully, with the aid of banks.

10.   The positioning of this intercept was important, presumably because once it was set, NB and SB would be measured and the distances to M and W deduced.

 There are probably other plausible survey sequences that can be proposed. However, this one has the strength that it aligns with the clear surveying objectives listed at (2). It also ensured that the Craddock Moor row line was precisely parallel to MW. Setting parallel lines may have still been important in the Circle survey -  as it clearly was in the Cursus survey.

Whether our sequence is correct or not, we do propose that the geometry of the remains cannot exist by chance, that the siting of the monuments on flat land with good views to Dartmoor supports a surveying narrative, and there is at least one plausible surveying explanation that matches the remains.

CHRONOLOGY OF Rows, Circles and BARROWS IN SOUTH WEST BRITAIN

On Dartmoor, large open stone circles (i.e. more than 20m diameter) are found within 100m of one or more stone rows at Merrivale, Scorhill, Sherberton, and Fernworthy. Shoveldown circle, with diameter 17.7m and just over 100m from the north end of Shoveldown row 3, may have had a similar function. Also, Sourton Tor cairn alignment is a tangent to the large circle there. There are though 10 other large circles on Dartmoor which are not in close proximity to a surviving row.

Some rows have circles at their ends. Whilst these circles are not ‘large’, in the sense of having a diameter greater than 20m, some are sizeable. For example, the diameter of the circle at the south end of Erme Valley row is 16m, whilst that at the at west end of Hingston Hill row is 13m. Most such circles are usually interpreted as cairn circles (i.e. surrounding a burial mound) but we wonder if some had a survey purpose initially, even if a cairn was later built within them.

The Craddock Moor remains suggest that the row, banks and, at least, two circles there are broadly contemporary because of their integrated layout. Given the site seems to have survey links back to Dartmoor non-megalithic rows at Merrivale, it is likely that that the Dartmoor non-megalithic rows and the Dartmoor large circles are also contemporary. A further hint is, perhaps, found at Sherberton and Sourton Tor, where the row lines are tangent to the stone circles. We hope to understand such relationships better, seeking to deduce for specific sites whether the row or circle was laid first, within the context that both assisted the same survey.

We have already found that many large barrows, both on Dartmoor and on the surrounding hills, lie on row lines. We suspect therefore that many of the rows, barrows and stone circles in Southwest Britain will prove to be contemporary and were built to support that same survey. 

Many of the stones of the Piles Hill megalithic row (on Dartmoor) today lie on the ground pointing in a similar direction. This suggests they were deliberately pushed over, because if they were left just to fall, one would expect to find random orientations. We have found indications, which need to be pursued further, that the Dartmoor megalithic rows are connected to the enclosure survey and/or the cursus survey. We suspect therefore that the megalithic rows, at least on Dartmoor, were part of an early survey and were decommissioned at the time of the circle survey.