Stonehenge: Neolithic Man and the Cosmos

Although they are similar, the mortuary houses at the two sites differ in ways reflected in the final forms of their associated barrows. First, it seems that one of the right angles within the quadrangle of scaling posts is exactly as before, but that the other is not. It seems to have been drawn to the axis, and perhaps relates to a post in Ashbee’s ‘Pit III’ at the centre of the four. Second, the Fussell’s Lodge example is not itself plainly associated with a pair of viewing ditches and there was certainly none for use with the scaling posts. As for the way they functioned, much the same procedure could have been followed as at Wayland’s

.

FIG. 21. Potential right angles in the (highly stylized) forms of the barrows at Fussell’s Lodge and Wayland’s Smithy, drawn to approximately the same scale.

Again it is necessary to consider viewing at right angles to near (qualified as explained) and far edges. In both cases the stars would have been the same. At an altitude of no less than 20.4° a perfect fit for the first alternative is produced, with Arcturus at declination 54.89° and Betelgeuse at –14.36°. The required year is 4240 BC.

FIG. 22. A cross-section of the ditches at Fussell’s Lodge (P. Ashbee’s section CD), roughly 15 m from the wide end and 25 m from the narrow. Note that the revetting posts have one third showing and two-thirds buried—a sound constructional principle.

Again it is necessary to consider viewing at right angles to near (qualified as explained) and far edges. In both cases the stars would have been the same. At an altitude of no less than 20.4° a perfect fit for the first alternative is produced, with Arcturus at declination 54.89° and Betelgeuse at –14.36°. The required year is 4240 BC—complementing in an unexpected but very welcome way the date (for the foundation barrow) previously obtained by averaging over individual (and different) stars, that is to say, 4235 BC.

Taking the second alternative, the altitude increases to 23.64° and the year is 4180 BC. In all cases small errors in the fundamental directions can alter appreciably the dates derived. (An idea of how sensitive the method is to error in the directions of key edges will be given briefly in a later section.) This alternative fits marginally more comfortably with the radiocarbon dates for material from the D-post pit (4250–3950 BC), but the first is to be preferred if Wayland’s style is to be followed. Far more important than those dates, however, is the fact that procedures derived from a study of Wayland’s Smithy can explain this monument equally well.

Was there a viewing ditch for the mortuary house? The palisade trench for the later barrow would not have served, for it would have been much too cramped, but short sections of the ditches known from the final barrow would have served very well. These ditches were relatively cavernous in the necessary region, reaching a depth of about 3.6 m below the base of the mortuary house. This great depth, slightly more than twice human height, might at first seem to be an insuperable objection to the idea that viewing was from them, but in fact the ground chalk is cut away, especially on the inside edge. The excavator, P. Ashbee, interpreted this as a weathering ramp, and no doubt some weathering has taken place—although presumably fairly uniformly. The angle of this ramp, however, is suspiciously close to what we require it to be, and not only in one section but in all seven places where Ashbee’s profiles allow us to measure it. To both sides of the house, an adult observer of normal height standing at the back of the true floor of the ditches—almost symmetrically now—would have been perfectly placed to look along a line barely skimming the ground at between 16° and 19°. The angles are not easy to measure accurately, but rejecting Ashbee’s section K (which lacks the flatness of the chamfer of the others, but certainly produces something in excess of 14°), the other six range from 16° to 19° and average at about 17.5°. This might not seem particularly close to 20.4°, but that is hardly surprising, for in its present form it does not belong to the mortuary house phase at all. It is a figure germane to the final barrow phase, and as we shall see shortly this figure is within a degree of what is predicted—again very welcome evidence in favour of the general principles being proposed.

The implied height of the ridge of the mortuary house is 2.45 m, almost identical to the height of the final barrow at this point, as estimated by Ashbee—although the loaf shape he favoured for the final barrow does not fit with the ideas being put forward here. Accepting the idea of two distinct phases, with the cairn an intermediary, building around the old house was just as rooted in tradition as at Wayland’s Smithy. Again, the form derived for the roof of the old mortuary house very probably resembled the flared form of the later barrow, for which there is the evidence of the palisade trench. It is conceivable, however, that the roof had a simpler form into which the gradients for the two different directions were nevertheless worked. The two alternatives are illustrated in Fig. 20 (#ulink_ad5c2b2b-1e84-5dbd-baef-21b6111c2166). The fact that the pit between the split trunks is somewhat east of centre seems to favour the flared alternative, for if the pit was meant for another short trunk supporting the roof, it would have been appropriate to place it at the centre of gravity of the roof. It is in fact placed precisely where one would judge the centre of gravity of the flared, barrow-shaped, roof to have been.

At Wayland’s, we worked back from the later to the earlier. At Fussell’s Lodge, we now know something of the local tradition, and also the directions of the bounding lines of the barrow across which viewing at right angles would have been planned. The outline of the later structure has been corrupted to some extent through the collapse of parts of the palisade trench, but averaging across sizeable lengths, the lines of sight seem to have been at 16.2° west of north and 23.3° east of south. From those data, using the same sort of argument as before, the conclusion is drawn that the date of the barrow was around 4180 BC and that viewing was at an altitude of 18.1°. The same star, Arcturus, was observed setting, but now the rising Bellatrix rather than Betelgeuse seems to have been observed. (The stars now observed were at declinations 54.63° and –17.83° respectively.) Even if viewing was at right angles to far edges, the same stars produce the only acceptable solution, with the altitude 20.23° and the year 4082 BC.

The lower angle seems preferable, as already explained. Other options might be thought relevant, for it does seem that the Fussell’s Lodge barrow has certain right angles deliberately built into it. (Fig. 21 (#ulink_4b5a949a-b13a-54e4-aeb4-9cee19d13b58) shows three, and the Wayland’s barrow is added, to scale, as a reminder of the arrangement there.) If, instead of viewing across lines a and d, lines b and c were taken, the (equal) altitudes of the same stars Arcturus and Bellatrix would have been about 16.0° and the year approximately 4140 BC. If planning was based on b and d, then the angle was 17.1° and the year 3960 BC. The differences are not as great as one might have imagined, and simplicity favours the original choice.

In appearance, with viewing at such relatively steep viewing angles (see Fig. 22 (#ulink_b67e11ff-a00d-513f-be2d-0b59ea069d89)), the barrow must have resembled an upturned boat. It is conceivable that there was chalk outside the revetting posts of the barrow, so that only the tops of them were visible. In this case, the whole thing would at first have taken on the appearance of an isolated giant white wave in the landscape. If duly trimmed as the stars changed their declinations, and regularly scoured to prevent vegetation settling on it, this form could have been kept for decades. The revetting posts would have rotted, perhaps within a century, but the downward wash of the cover might have been repaired even for several centuries. Of course it could be that alignment on stars was merely a foundation activity, regarded as done once and for all, and that the stars were not observed over the barrows thereafter, or were observed for only a few years. Perhaps, in time, closer attention to ditches will produce the much-needed evidence—the burning of lamps on the walls, the tread of feet on the floor and on sloping platforms, provision for drainage inside and on the lip, scouring tools on the ditch bottom with unexpectedly late radiocarbon dates, and so forth.

It has been shown by experiment that weathering of the surroundings of a ditch can cause it to fill in five or ten years, and it has usually been taken for granted that the ditches of a long barrow filled up quickly in this way, soon after its completion, since it has been assumed that the only purpose of the ditches was to provide raw material for the barrows. If the barrows were used as suggested here, however, and not merely in a foundation activity, then they would have been regularly cleared of rubble, baled out, and possibly even recut from time to time, to accommodate changing star positions. They might even have been given penthouse roofs to keep them dry, and so have weathered much more slowly than if they had been exposed. This last is a purely speculative remark, in the absence of any remains; but such roofs would have been as nothing by comparison with those often postulated for circles like the Sanctuary and Woodhenge, which would make them into prehistoric equivalents of St Paul’s Cathedral. And needless to say, the bigger the roof postulated, the more surprising that no traces of its fallen timbers have been found.

Lambourn (#ulink_729f15f2-ebf5-5b08-bde1-afded0d38278)

A radiocarbon date for the long barrow on the Lambourn Downs, 4 km north of Lambourn, provides it with a venerable status that has not had much influence on its preservation. Corrected in the usual way, the date falls in the calendar range 4200 ± 200 BC. Part of the long barrow not in woodland has been badly ploughed down, and part in woodland has been interpenetrated by tree roots. It was excavated in a peremptory way by Martin Atkins in the 1850s and rediscovered by Leslie Grinsell in 1935. It was so ruthlessly ploughed that a rescue excavation was mounted in 1964 by John Wymer, who found that very little remained of the exposed mound.

Grinsell described it in outline, and following his plan its central axis seems to have been about 74.7° east of north, which is probably true to better than a degree. Wymer’s plan is more detailed, and shows that the ditches were tolerably straight, and had mid-ditch azimuths (corrected for 4.0° compass error) of about 76.2° (south side) and 73.2° (north side). The average corresponds exactly to the figure obtained from Grinsell’s plan. It differs only slightly from that of the Fussell’s Lodge barrow, but so, of course, do the geographical latitudes and horizon profiles at the two places, and the conclusions to be drawn from the two are very different.

Scattered sarsen boulders are still to be found at the eastern end of the barrow, deriving from a chamber there, and at the exposed western end many of the boulders still lying at the edge of the field are what were removed by the farmer, through deep-ploughing. The modern partial excavation of the head of the mound, within the wood, revealed that sarsen boulders in the mortuary area followed a well-defined line (azimuth about 72°). The Lambourn barrow was perhaps a two-stage structure, like those at Wayland’s Smithy and Fussell’s Lodge, containing a primary wooden-framed tomb that was covered over by the present barrow at a later stage.

Atkins, who tells us that a farmer had already dug into it before him, and that ‘human remains and a quantity of black earth’ were found, also unearthed other skeletons. One was lacking its skull—as a result, he thought, of the farmer’s enthusiasm. More recently, Wymer found a crouched burial in a rough sarsen stone cist, together with seashells, but this was not a primary burial. It is unfortunate that the character of the first structure is unknown, and that we are left with only the decrepit remains of the outer barrow as a guide.

The slope of the badly worn mound when Grinsell charted its profile in 1936 was about 2.3° upwards to the east, and an estimate of the barrow’s maximum height to be made shortly suggests that it might originally have been about 3.0°. The critical land horizon (eastwards) is 2.02° and had there been trees on the horizon 10 m tall, the angle would have risen to 2.32°. (Corresponding western altitudes are 1.54° and 1.97°.) It looks very much as though, just as at Fussell’s Lodge, the slope of the barrow was made to mask the distant horizon, as would be explained if the viewing of a rising star to the east was along its spine by a person standing in the natural hollow at its western end. This appears to have been a ditch, judging from old aerial photographs, and Grinsell took it to be such, like those he knew from Dorset barrows, but Wymer did not detect any such ditch.

Accepting an azimuth of 72° for the line of the barrow’s sarsen core, the rising of the star Altair would have been seen at the stated altitude around the year 3960 BC—a very tentative date, of course.

The barrow was certainly tapered, like that at Fussell’s Lodge, and judging by the ditches the taper amounted to only about three degrees. Observation towards the west was also in principle possible, using the natural horizon. Another way of looking at a star on the western horizon would have been to use the gentle incline up to the tomb entrance from the place of the present road (there is no path in that position now). A person of average height would have seen the foreground (land, track) coincide with the far horizon—assuming trees of more or less 10 m. The high end of the tomb, at 2.6 m above the surrounding ground or thereabouts, would have made a third (intermediate) horizon for the ray to skim, rather as at Wayland’s Smithy, which is less than 5 km away. The artificial altitude would in this case have been 2.0°, which is the extinction angle for the most likely star in that direction, the setting star Aldebaran. There is little point in setting down what are no more than directed guesses, based on a very superficial survey, but a line of sight of azimuth 250.5° would have been needed for the fortieth century BC, not far from the reverse of the supposed direction to Altair’s rising. Both of these alignments might have been embodied in a set of scaling posts, as at the head of the barrows at Fussell’s Lodge and Wayland’s Smithy.

Another possible observation along the barrow to the west could have been in connection with the setting of the Pleiades at the same period, as at Wayland’s Smithy. Not enough detail is known of the Lambourn structure to speculate on a precise alignment. Another long barrow over which the setting of the Pleiades might have been observed is at Nutbane, in north Hampshire, 20 km or so from Stonehenge, a barrow that is perhaps five centuries younger.

The use of the Lambourn barrow as an artificial horizon for crosswise viewing admits of two distinct solutions. One of these involves the setting Arcturus to the north together with the rising Bellatrix to the south. The estimated date (4272 BC) fits well with the corrected radiocarbon date of 4200 ± 200 BC, and yet reluctantly the solution must be rejected. It requires viewing in both directions at an angle of approximately 19.0° to the horizontal, a figure that implies a mound 4.7 m high, seemingly much more massive than the ditches could have provided.

The alternative solution, which is tentatively accepted, is that the setting of Vega was observed to the north and the rising of Sirius to the south, around the year 3970 BC, both stars being viewed at an altitude of 11.0°.

The implied maximum barrow height (2.6 m) fits very well with what is known of the ditch sizes and their potential for providing material for the mound. The derived date is probably not in error by more than a century. The dates obtained for Altair and Aldebaran along the barrow’s length are compatible with it, but why then does it not square with the radiocarbon date?

The latter was based on a patch of burnt wood from the floor of the tail end of the south ditch. It could have originated with timber from an old mortuary house, or from posts that had been removed from an old structure by burning—broadly speaking, the bigger the post the older the timber. As one of the long barrows at Skendleby will later demonstrate, a set of more than a dozen radiocarbon dates from a single site may span two millennia, and any one of them in isolation might have given an entirely false impression. In a sentence: the Lambourn barrow we (barely) know is perhaps not as old as is generally supposed.

Although the Lambourn barrow is now in a relatively isolated spot, there was considerable later prehistoric activity nearby. It is unlikely to have been by chance that, almost in line with it, and half a kilometre to the east, is a disc barrow. Mostly to the southeast of it, and within a circle of radius under a kilometre, there are remains of at least thirty round barrows of various types of the early and middle Bronze Age. A dozen of these lie together in a group with the collective name of ‘Seven Barrows’ (the English having always found barrows difficult to count), and six of them lie virtually in a line that passes directly over the long barrow, while another four lie roughly on another line, parallel to the first. The former and better alignment is about 40° north of west (or south of east), but this depends on how one selects the barrows, for the line is not perfect. It seems obvious that these much later tombs were aligned on the setting of the Sun over the long barrow at the summer solstice—a direction which changed very slightly with historical period. (The calculation depends on the horizon altitude, which in turn depends on the line chosen.)

It is hard for us now to comprehend how such a simple mound as the Lambourn long barrow could have kept its reputation as a place of great sanctity for perhaps two thousand years after it was first erected. Having accepted the idea, however, we seem to catch a glimpse of one reason for shifting allegiance away from the stars to the Sun in these matters of alignments: the directions of the Sun’s risings and settings are more or less constant over very long periods of time. For most of the stars this is not true, even though Deneb, as we have already seen, had a certain constancy in its behaviour.

Horslip (Windmill Hill) (#ulink_e48b079b-8da8-5fee-afc1-a9a48a293f24)

One of the most valuable of modern reports on long barrow excavations is that in which Paul Ashbee, I. F. Smith, and J. G. Evans describe respectively excavations that took place between 1959 and 1967 at Horslip, Beckhampton Road, and South Street, all in or near Avebury. The Horslip barrow lies a kilometre due south of Windmill Hill, and so is often called after that enclosure—which in turn has given its name to a whole culture. Selected radiocarbon dates for the three barrows produce the ranges 4000 ± 160, 3550 ± 185, and 3300 ± 100 BC in calendar years (3240 ± 150, 2750 ± 135, 2517 ± 90 bc). There is no unambiguous evidence that any of these barrows was built in more than a single phase, although Horslip probably was; and none has produced evidence that it was used for burials at all in the earliest phase, a discovery that has caused much surprise. All three barrows have been ploughed down considerably in recent centuries, but even so, the second and third retained extremely valuable clues as to the astronomical and architectural procedures followed by those who built them.

FIG. 23. Plan of the Horslip long barrow. Details of most of the inner area had been removed by ploughing. The letters indicate Paul Ashbee’s ditch sections. The broken-line trapezium represents no more than a directed guess at the outline of the limits of the barrow. The line of pits at the north western end might represent viewing positions for an earlier mortuary house on the site.

The Horslip barrow was originally perhaps of trapezoidal form, since the ditches that flank it are slightly splayed (Fig. 23 (#ulink_6ec3f4df-5acb-5d98-8cf7-ee4dd0b7c117)). In 1743 William Stukeley described it as being ‘of large bulk, length, and height’, but ploughing after his time virtually removed all surface features. Its orientation was roughly 45° south of east, and in this direction the ground falls away. The southeastern end is the higher in relation to the surrounding ground, but the overall slope of the ridge of the barrow when it was erected was very probably between four and five degrees upwards in the opposite direction, that is, to the northwest. Observation in this direction seems unlikely, for want of bright stars, but looking the other way, over the natural horizon, the rising of Sirius might have been seen. The line is not securely known, and trees might have been a factor, but all plausible directions indicate a date within a couple of centuries of 4000 BC.

FIG. 24. Sections of the ditches at the Horslip long barrow, with labels following those of Fig. 23 (#ulink_6ec3f4df-5acb-5d98-8cf7-ee4dd0b7c117). The lines of sight are arrived at entirely on astronomical grounds. The verticals represent the height of the eye of a male observer of average height. The broken horizontals show the excellent levelling of observing positions, which ditches purely for quarrying purposes would not have had. The maximum height of the barrow can be judged easily enough from the suggested lines of sight, and is not indicated. The broken lines of sight are what might have been used had the ditches changed direction here, for example with a lower barrow. Note that observers’ heights may still be equal.

The orientation of the barrow can be estimated from the average direction of the inner edges of the ditches (135.0° for the northeastern and 140.8° for the southwestern), or from an interesting pair of pits (134.5° through their centres) that might well have been related to the line of the ridge itself, or perhaps to that of an earlier mortuary house on the site, as at Wayland’s Smithy. The pit near the northwest was roughly a metre square and three quarters of a metre deep; the other, about a third of the way up the ridge from the southeastern end, was circular in section and had dimensions about a third as great as the first. Other pits in a rough line following the southwestern edge are also represented in two cross-sections of the ditches, illustrated in Fig. 24 (#ulink_c69256fa-eaa0-5000-ac53-c7818adb31cd).

Even from a single ditch, there are possibilities of multiple viewing positions. It is conceivable that the pits (here at b and d) are meant to add more, but the spread of a reasonably stable mound, of a height to be suggested shortly, makes it more probable that they are vestiges of an earlier phase in the history of the barrow, perhaps relating to the two pits on the axis. The ditches are interesting for their equalization of the lower levels, the places which on our basic assumption offer the ideal positions for viewing. Section E appears to be an aberration, failing to conform to our principles, and yet in the EF section there is a ledge providing viewing from the very same level. A change of ditch and barrow directions here could well have changed the requirements for viewing heights, to fit a later date, but still, it seems, the possibility of viewing at equal angles is being retained. The height of the spine of the barrow above the old ground level was perhaps around 3 m. The evidence for this comes from the astronomical possibilities offered by the lines of the ditches.

Applying yet again the principle of viewing at equal altitudes, at right angles to barrow and ditch edges, near or far, there is only one likely star to the north, namely the rising Deneb, but to south there is a choice of two, Aldebaran and Betelgeuse. The setting of Betelgeuse seems preferable, since it produces dates fully consistent with the radiocarbon date—which came from a piece of horn of red deer from a ditch fill. Taking the option of right angles to near edges, the date is 3809 BC (altitude 16.21°), while far edges give 3940 BC (altitude 12.26°). Coupling Aldebaran and Deneb, the angles would have been little changed, but the date would have moved earlier by three and a half centuries. Out of these four options, 3940 BC seems most acceptable. (The latitude is 51° 25' 58". Azimuths are taken as 50.8° and 224.7° (near) or 44.7° and 230.8° (far). The favoured declinations are: Deneb 36.76° and Betelgeuse –12.69°.)

In the case of the Horslip barrow, there is an odd piece of evidence supporting our preference. There is no chamfered inner edge to the ditch to suggest a viewing altitude, but if one tries to superimpose lines of sight on the ditch sections (as in Fig. 24 (#ulink_c69256fa-eaa0-5000-ac53-c7818adb31cd)) the floors of the ditches turn out to be better suited to the lower angle of view (12.3° rather than 16.2°), in the sense that they can accommodate more usable viewing positions. The sizes of the excavated ditches therefore give a rough idea of the height of the barrow, twice over, since they also provided the materials for it. They are quite consistent with the implied height of around 3 m above eye level.

The finer points of barrow construction, as illustrated by Fussell’s Lodge and Wayland’s Smithy, are at Horslip completely beyond recall. As already suggested, there was very probably an alignment down the line of the barrow’s axis on the setting of Sirius over natural ground (the declination being around –26.2°). This in itself would have been notable enough, in combination with the alignments on Deneb and Betelgeuse, but in the thirty-ninth century BC the Horslip site had another very remarkable property: the natural horizons there are not equal, but are such that the direction of the rising of Sirius was then at right angles to that of its setting. (Without tree cover the extinction angle was operative to the southeast but the altitude to the southwest was 1.26°.) In view of the Neolithic preoccupation with right-angled viewing, this would have endowed the site with exceptional importance, even though the right-angle property was relatively short-lived, and within a century or so was to be lost. But was it matched by another, which persisted?

It will be shown later in this chapter that the planet Venus, the brightest of the planets, might just have been seen when she was at her southern limit of setting, along the same direction as Sirius. The planet would have had this property already in the fifth millennium, and would have kept it long after it ceased to hold for Sirius. While it is a property to which one is led by considering the barrow, it is really one that belongs to the site. There are later qualifications to be made, in regard to a fundamental difference between Venus’ extremes of rising and setting, but assuming that the property was discovered at the time to apply to Sirius and to one or more of the four extremes of Venus (risings, settings, north or south), there would have been ample reason for building a barrow along one of the key directions. It is just conceivable that this property influenced the choice of a site for the Windmill Hill settlement in the first place.

West Kennet and its Star Chambers (#ulink_247fbe6d-256d-53d7-b108-7723ba080366)

Today almost as well known as Wayland’s Smithy, the chambered long barrow on a ridge of the chalk downs to the south of the hamlet of West Kennet in Wiltshire is even grander in scale. Just over a hundred metres in length, and tapering from about 24 m at its eastern façade to 12 m at the western end, it is (with that at nearby East Kennet) the largest in the region, and among the largest in the country. Its sheer size has enabled it to survive a number of crude onslaughts. One of these was by a certain Dr R. Toope of Marlborough, who in 1685 raided it for bones, for their supposed pharmaceutical properties. John Aubrey gave a vague account of the tomb at about the same time. It is in a letter to him from Toope that we learn of the doctor’s attitude to prehistory, and of how already in 1678, alerted to the large quantities of bones in the area around the Sanctuary nearby, he had acquired ‘many bushels’ with which he had made ‘a noble medicine’ that relieved many of his distressed neighbours. (One might doubt whether those particular bones, lying near the surface and closely packed in the open field, skull to skull, were prehistoric at all, although Toope did insist that their feet were all directed to the Sanctuary.)

William Stukeley made valuable drawings of the West Kennet long barrow, and described it, in 1723–4. ‘It stands east and west’, he wrote, ‘pointing to the dragon’s head on Overton-hill.’ (This is the hill on which stood the Sanctuary, now known to have comprised a succession of concentric rings of timber posts, before they were replaced by rings of stones.) The long barrow was partially excavated in 1859 by John Thurnam, who reported that farmers had cut a wagon-road through it, and had raided it for flints and chalk rubble. The definitive excavations were done in 1955–6 by Stuart Piggott and Richard Atkinson, like those later at Wayland’s Smithy.

The West Kennet barrow has much to tell us about the evolution of a single long barrow, but it shows, too, that it is a mistake to consider that changes in ditch direction necessarily imply additions to an old barrow at a later time, as is often supposed. It will be discovered that it was probably built in two distinct phases, a century or so apart, but that there is a change in direction within the first barrow. Quite apart from its intrinsic interest, this long barrow has an importance deriving from the fact that it is in the neighbourhood of an extraordinary complex of prehistoric remains. Silbury Hill, the largest man-made mound of prehistoric Europe, is less than a kilometre away (NNW), and less than 5 km in the same direction is Windmill Hill. Roughly 1.3 km east of the barrow lies the site known as the Sanctuary, and from there the Kennet Avenue of stones stretched, initially roughly westwards, then turning closer to north and heading for the southern entrance to the stone circle at Avebury. (The Avenue will be discussed again in Chapter 5 (#litres_trial_promo).) Avebury, by far the largest of all British stone circles, is only a little over 2 km to the north of the West Kennet barrow. The almost equally large long barrow at East Kennet is just under 1.5 km to the southeast. On most days, all of these places are to be seen from the West Kennet barrow.

The barrow is flanked by ditches, running alongside it for all of its length. Its orientation was said by Stuart Piggott, in his report of the excavations, to be 265° 20'—that is to say, a person looking at the façade would be facing 4° 40' south of west. To define an axis, however, one must be able to identify the intentions of the builders, and this figure presumably rests on the assumption that the stones of the central passage were set symmetrically about an axis that agrees with the spine of the mound. Another interpretation, to be offered shortly, substitutes a figure of 267.0°.

FIG. 25. Sections of the West Kennet long barrow, as drawn by Stuart Piggott.

The mound had a central core in the form of a long cairn of sarsen boulders, rising to about 2 m in the excavated section. This core was in turn overlaid with chalk rubble from the ditches, and at the higher end this virtually doubled the height. A kerb round the barrow, resembling that at Wayland’s Smithy, was robbed of its stones long ago, and consequently a much less accurate picture is available of the outline of the tomb. As for the difficulty of assessing the orientations of the sides, their sheer length makes this a little easier, compensating to some extent for the loss of the kerbstones. The northern ditch apparently changes direction so that it is in at least four sections, while the southern ditch is in at least two. The bounding edge of the mound seems to follow those changes closely (Fig. 26 (#ulink_8ca8362e-e6fe-551a-9918-fb9608e1bd96)). Viewing across the barrow, it will be shown that section A was paired with B, but not with C, which is a linking section only, while D was matched with both E and F, but at times a century apart.

FIG. 26. Outline plan of the West Kennet long barrow and ditches, showing the deliberate changes of direction, resulting in four sections to the north but only two to the south. (The inset scale at upper left is 10 m long.)

The most obvious stone structures, now largely restored, are at the eastern end, built out of massive local sarsen stones and dry-stone walling of oolite slabs. The sarsens were brought up the hill perhaps 2 km or more from the southeast, and the smaller stones from a distance of 10 km or more. The chambers form a ‘cross of Lorraine’. They are arranged around a roofed passage running for more than 8 m down the spine of the barrow: a burial chamber opens off it at its end, lengthening it to 12 m, while two others open off at each side. The passage is as high in places as 2.3 m. It is entered from a crescent-shaped forecourt formed out of large but rather irregular uprights, and a false front closes off the forecourt, making the façade seem more or less flat. There are two stones flanking the entrance, immediately behind the large blocking stone in the middle of the façade. They should not be dismissed as merely helping to seal the entrance, for they have another important function. As will be seen from Fig. 28 (#ulink_d34eb058-3952-5dfa-9a69-fe0a933ba574) (from which blocking stones are removed), they help to limit lines of sight from particular points within the five chambers. These lines of sight—of which more shortly—seem to have been directed to five significant stars.

FIG. 27. The five chambers at the eastern end of the West Kennet barrow, with surviving blocking stones in position.

FIG. 28. The West Kennet chambers with blocking stones removed, showing potential lines of sight, limited by the edges and faces of stones. The other lines added to the figure (see also Fig. 29 (#ulink_5c45e277-44bb-548b-8ea8-8cc634571fa7)), show the great care that went into the planning, and justify the position given to the axis.