Stonehenge: Neolithic Man and the Cosmos. John North

FIG. 48. The two Grendon ring ditches surrounding the earlier square barrow. The broken circles are the suggested aims of those responsible for the ring ditches. Their centres are marked (near the upper crossing of lines of sight), and they are shown in the inset figure in more detail.

      The similarities do not end here, for despite their utterly different orientations—one is almost at right-angles to the other—the two barrows were clearly designed for observing Deneb twice over. The rising of Deneb would have been seen at Grendon by an observer in the ditch at D, looking over the mound along a line parallel to the inner edge of the southeast ditch. The azimuth of this is taken to be 45.5°, so that it would have fitted perfectly with the angle assumed for cross-viewing. They are not perfectly at right angles, but only a degree removed, and if the error is ours, rather than theirs, then the date—as alluded to earlier—moves to about 3550 BC. Like Skendleby 2, therefore, Grendon was aligned twice over on Deneb and once on Betelgeuse; but now, four or five centuries on, the last alignment is not on the setting but the rising of Betelgeuse.

      The other important similarity of function involves solar observation. To decide this question it is first necessary to make an estimate of the size of the mound. One cannot say exactly where were the preferred positions for crosswise viewing, but those marked A and D (for Deneb’s setting and rising, respectively, parallel to the lines a and d on Fig. 47) and B (for Betelgeuse’s rising, parallel to b) are the most likely, in view of the large post positions, and the lines crossing over the centre of the square seem the most significant of all. The proximity of the crossing point to the centres of the ring ditches adds credence to the idea that the mound was at its highest there. Even though there might originally have been a ridge, it would in any case have passed through this point. The height needed here, to set equal angles of 12.7° to observers in the three viewing positions, is about 1.9 m above eye-level. Perhaps the ditches were in fact 1.9 m deep at the appropriate places, so that by standing at ground level an observer could have seen the natural horizon over the mound from any position around it. If the eye of a normal male observer was at ground level—our previous findings fitted perfectly an assumption that the height of a man’s eye was critical—then the mound would have been about 23 cm above his eye were he to have stood at ground level. It is not even necessary to make this assumption, however, to make a claim for solar viewing at the site: the southernmost pair of posts would have been usable in connection with the natural horizon, using the line (at azimuth 132.4°/312.4°) marked on the figure, in order to observe the rising midwinter Sun in one direction and the setting midsummer Sun in the other. This is so because at a conservative estimate the height of the mound here would have been no higher than about a metre, and it might have been less. (The placement of such a sight line with respect to the posts in the manner shown was to become standard, as will be discovered in Chapter 7.)

      What is surprising here is the fact that, at a mere glance at the Grendon plan, midsummer sunrise or midwinter sunset would have been thought the likeliest candidates, either of them viewed along the axis of the barrow, just as at Skendleby 2 we found midwinter sunrise and midsummer sunset along its axis. At Grendon, this method is impossible; but by taking a line across the barrow, it is clear that what was observed could have been exactly the same as at Skendleby 2, namely midwinter sunrise or midsummer sunset or both. (It is also possible that these phenomena were observed by looking along the façade in some way.)

      The Grendon barrow is of greatest interest, not because it mirrors a much earlier style but because it seems to signal the approaching demise of the truly long barrow. This was not to occur for several centuries, but neither was the transition a sudden one. Beckhampton Road was built at least a century after Grendon, and was converted to a round barrow presumably more than a century after that. Long chambered tombs in stone were probably still being built in the third millennium. Grendon shows that it is unnecessary to postulate an invading culture, such as the ‘Beaker People’, to see how circular barrow-forms might have arisen quite naturally. Of course it is not being suggested that it was Grendon in particular that supplied Neolithic peoples with the idea that barrows might just as well be square, or round, as long—Radley, after all, had even greater economy of line than Grendon. It is rather that this barrow is symptomatic of changing Neolithic attitudes to barrow construction. It symbolizes too the great naturalness of three prominent features in those circular mounds that qualify as early ancestors of Stonehenge: (1) the circular ditch, which is no more than a rationalization of the encircling ditch of a shortened long barrow; (2) a low mound of height roughly equal to that of the human eye, within that ditch, and corresponding in some way to it; and (3) an assortment of posts within the mound area, at first arranged for crosswise viewing, and later supplemented by others in ever more perfect circles.

Hazleton North and Burn Ground—Cotswold–Severn Long Cairns

      Whilst the chambered long barrows at Wayland’s Smithy and West Kennet fit easily into the Wessex tradition, they also have affinities with the Neolithic stone long barrows (long cairns) of the Cotswolds, which might just as reasonably be considered their natural neighbours. (West Kennet is little more than 20 km from the string of known examples, and the isolated Wayland’s Smithy is hardly further from several at the northern end of the string than it is from West Kennet.) The differences are chiefly in the material used, although—threatened by endless classifications of type—it is wise to add that there are many differences of design too. Where easily split stone was plentiful it was used for the mound, and if larger upright stones (orthostats) were not locally available, then they were imported, from appreciable distances, if need be. Most barrows in the group were essentially roughly trapezoidal in plan, often with a Cupid’s-Bow wall at the high end (usually referred to as ‘horns’). Almost all seem originally to have been surrounded by a dry-stone revetment, a containing wall that even when excavated is usually found to be remarkable for its straightness along the sides. Changes of direction are much rarer than with earthen barrows, no doubt because good viewing positions are much harder to create along the length of the barrow, in a stony district. Like so many earthen barrows, there is a clearly identifiable spine, now usually of slabs of stone pitched together. Some of the stone barrows—perhaps all—have internal walls running across the width of the mound, dividing them into cells.

      These internal walls are exactly analogous to the much flimsier lines of stakes found in so many earthen barrows, and clearly mark the stages of construction. The conjecture made earlier in this chapter, that the stakes were deliberately set in the directions of lines of sight, and at right angles to the neighbouring or far barrow edge, is harder to test with a dry-stone wall, but all the evidence suggests that the same