Interpreting ancient monuments involves both science and speculation – but wondering what might have been is half the fun. There are many unanswered questions about the Birkrigg stone rings; in fact very little has been written about them. I wanted to share some of my thoughts and researches on these issues although, in places, these may not be the conventionally accepted view. Closer inspection reveals much more than just the dramatic position of the stones revealed in part 1.

Birkrigg's rings may not be large and dramatic with full of celebrity status but they are amongst the most important, but under-rated, in the country because they have several rare and distinctive features. As we have seen they form part of an extensive array of Bronze Age settlements.

The Sunbrick "circle" actually comprises two rings of stones, neither of which is truly circular. Double rings are rare - only 15 of some 400 rings still in existence in Britain have this feature. The outer ring may well have been added at a later date than the inner ring. Unfortunately, in recent years, the stones of the outer ring have fallen and are now often obscured during the summer months by bracken. However, in 2015, a group of local volunteers managed to get all the necessary permissions and have been trying to clear some bracken on the Common at key wildlife and archeological sites, including the outer circle.

The outer ring is incomplete towards the north-east and is shown as such on all old plans. One wonders whether it was ever more than a horseshoe arrangement. Curiously, the other double ring on limestone in Cumbria, Gunnerkeld (Shap), is also incomplete at the north-east. This might make sense as the “horseshoe” opens out towards the mid-summer sunrise beyond Chapel Island (the horseshoe arrangement of trilithons at Stonehenge opens out towards the mid-summer sunrise)......

Most of what little we know about the Sunbrick rings comes from two archaeological digs carried out in 1911 and 1921. These were very amateurish by today's standards - three besuited gentleman (one a vicar, one a bookseller) stood around while a farm worker dug with a spade!

The diameter of the inner ring was given as 24 feet in 1911 and 27 feet in 1921. Actually, neither is particularly informative as the ring is far from a circle, stones 4 and 5 tending to bulge towards the south-east (see plan below). Taking the circle on which the majority of the stones lie gives a diameter of 26 feet (some would argue that this is exactly 10 Cumbrian “yards” - such a yard being equal to 0.794 metres or one man’s pace).

In 1911 there were only ten visible stones in the inner ring (see diagram below). Today you will notice two additional stones, both barely showing above ground (1a and 1b on the diagram below). These were discovered during the 1921 dig and left uncovered, as a record from 1850 had indicated that there were 12 stones at that time. I have marked these on the map below along with the major sun and moon events but, although some stones seem to have alignment with these, the inner ring is too small to serve this purpose accurately and the stones are too small to guarantee that they have not been moved down the ages. However, the concentration of stones in the north-east sector suggests that stones 1a and 1b may have indicated the extremes of mid-winter moonrise between the major and minor lunar standstills. *

* Just as the rotational axis of the earth is tilted relative to the orbit of the eath round the sun causing the position of sun rise to vary between south-east and north-east, the tilt of the moon on its axis means that the position of full mid-winter moon progresses from further north than the mid-summer sunrise to further south, and back again; this follows a 19 year cycle, with the extremes being known as the major and minor lunar standstills. Meton, of Ancient Greece, noticed that it takes the moon 19 years to reappear for the first time in exactly the same point in the sky (i.e. in precisely the same position within the zodiac constellation) and in exactly the same phase. This also creates the 19 year cycle of tides.

The 1911 dig discovered that the inner ring was paved with a layer of “cobbles”, some three to six inches (10 to 15 cm) below the surface, separated by a thin layer of earth from a second layer of cobbles beneath. In the centre of the pavement was a circular saucer-shaped depression just over 3 ft (1 metre) across. Local myth has it that these cobbles came from the shore, but they were described in the report of that dig as being of “blue rag”, a term used in those days to describe local blue slate. This suggests the use of the hard blue stones (of slate) found in the limestone quarried on the Common; many such blue “eggs” have been dug out during quarrying and incorporated into the limestone walls or left scattered around. These often break with a flat face, which would have made them suitable for paving and perfect as the flat-faced stones that were reported to be wedged around the stones of the inner ring, helping to hold them upright as the stones of the ring were not buried to any great depth.

Two stones of the circle have a special significance. The “north” (1) and “south” (6) stones have male and female connotations. The long thin male and bulky female stones are typically found in other Cumbrian rings (like Swinside) and elsewhere (even Britanny). At Sunbrick the female stone (below right) is sometimes referred to as the “whale stone” (because of its resemblance to a whale's head) and was at one time thought - incorrectly - to have been carved. The positions of these stones would have been determined by bisecting the positions of sun rise and sun set on any one day and are consequently a little out of alignment with the true north-south axis.

At Sunbrick there is also a deep trench running along the north-west side of the rings; it is several metres wide and almost 100 metres long and has always puzzled observers. It is obscured by bracken in summer.....

This trench has never been excavated or examined archaeologically. However, at the bottom of the slope it is aligned with Chapel Island, but as it skirts the north-west side of the rings it curves slightly to align with the mid-summer sunrise and the mid-winter sunset. It is possible, but I think unlikely, that the trench is a natural formation (streams don't form on Birkrigg) and it may have been dug as a processional feature. Whether true or not, I like to think it was dug with the shoulder blades of auroch used as spades! The skull of an auroch was discovered in 1955 near the shore opposite Chapel Island (in the photo above).....

A close examination of many of the stones of the inner ring , especially of the male and female stones shows that they have been eroded down the centuries. It looks like weathering, but actually a secret agent has been at work ........

The agent of attack is snails. The snails of Birkrigg featured in a scientific paper in the Geological Magazine in 1870, which led to a general acceptance that snails can digest limestone, creating deep cavities (saxicavous behaviour). The cavities on the stone circle are found on the leeward side, out of the sun and the prevailing winds. It is not unusual to find a snail occupying a hole in one of the stones, often a perfect fit.

In the autumn, Brown-lipped Banded snails make preparations for winter and large numbers of them can often be found “feeding” on the limestone – it is thought they secrete an acidic fluid at this time which enables then to dissolve the rock and take up the calcium.

It has been estimated that it takes a snail ten years to deepen a hole by 1 mm, so some of those holes must represent many hundred years of effort, by many generations. It appears that something in the formation of the limestone at particular points on the limestone appeals to the snails and this is where they concentrate their effort.

In the summer months, many visitors find that the stone rings are hard to find, as SLDC have failed to provide a single signpost to them and they are obscured from the road by bracken. By August the rings themselves also look terribly overgrown and neglected. It is not unusual to find the ground scarred by barbeque fires and pitted with holes that have been dug to bury cremation ashes or plant remembrance flowers.

Not only is it selfish to commandeer this public place in this way it is also illegal, as this is a very important Scheduled Ancient Monument. It has stood here for over four thousand years as a spritual place and deserves to be treated with more respect.....