The façade sets a good line at right angles to a row of thin stakes (see Fig. 40, azimuth 133.8°) at its centre. It was likewise almost exactly perpendicular to four posts of intermediate size at the northeast side, which were no doubt an aid to setting out the façade, with properties to be explained. The direction of the façade is comparable with that of the front edge of the mound and that of a transverse stake fence on the northern side, but again these will be kept in reserve. It will be assumed that viewing across an unspecified mound (not the last erected there) from the northern ditch was done at an azimuth of about 223.8°. This is the second crucial azimuth.
FIG. 40. Outline of the Skendleby 2 long barrow. The coarse broken lines pick out some of the symmetries of the plan. Lines numbered 1 and 2, passing through the gap in the façade, are sight lines for solar observation in two directions. For further detail see Fig. 41.
Combining it with the first, in the now standard way, one finds that the rising of Deneb could have been seen over the mound of Skendleby 2A to the northeast from the southwest ditch at altitude 13.96° around 4020 BC, together with the setting of Betelgeuse at the same date and altitude, looking from the other ditch to the southwest.
In this first phase of the monument, the ditches might well have differed somewhat from the later ditches, as is known from the excavation, but it must be said that the change cannot have been great, for what is known of them fits very well with the derived viewing angle. The ditch to the front, moreover, is everything that we could wish for. By a fortunate chance, the excavators took a section almost exactly where it is needed. The short row of stake holes in front of the façade (not to be confused with the long row along the axis) meets the front ditch at a very special point indeed (Fig. 41). Lines from this point to the extremes of the observation trench run due west and due north. (This is our oldest example of a more than tacit occurrence of precise cardinal points.) Not only this, but there are two steps cut into the chalk at this point (see the right-hand side of Fig. 42), and from the upper step, observation could have been made over the top of the façade at the very angle (nearly 14°) to be derived from the assumption of cross-viewing from the side ditches. This angle has two remarkable properties. First, it allows the setting of Deneb to be seen in a direction virtually identical to that of the line of stakes in front of the façade, at the same date as the crosswise observation of Deneb’s rising. (The discrepancy in azimuth is about a quarter of a degree, which is of the same order as the accuracy of our present measurements.) Second, taken in conjunction with the levels of the ground and distance of the ditch, it carries the important implication that the height of the eye of a man of normal stature making the observation would have been exactly the height of the operative posts in the façade itself. In other words, the same man could just have seen over the relevant part of the façade, had he stood against it at ground level. The assumption here is that the height of the eye (E, in the figure) is made equal to that of the average West Kennet male (nominally 1.66 m).
It is hard to avoid the feeling that the near-perpendicularity of the two Deneb directions was the result of an attempt to make them precisely so. Had they been so then each would have been precisely 45° from north, that is, yielding azimuths of 315° and 45°, rather than 314.2° and 45.8°. The discrepancy might have been adjusted by a slight difference in viewing altitudes. It is not likely to be entirely due to our own error in the azimuths, since the need to bring Betelgeuse to the same altitude was surely enough to thwart any ambition to produce a Deneb right angle. What is certainly of great interest is the similarity between the Skendleby 2A’s use of perpendicular sighting lines to Deneb and the presence of perpendicular sighting lines to Sirius over the natural horizon at the Horslip long barrow. The date assigned above to that barrow was only three quarters of a century later than the date obtained here for Skendleby 2A.
The façade held thirty-one posts, and showed signs that at some stage posts had been removed by burning. This is of course one of the easiest ways of removing an old heavy post, but it should not be assumed that removal was once and for all. The façade functioned, if the present analysis is accepted, for many centuries, and might have been replaced many times. Traces of the posts of the façade show that they were by no means of constant girth, and some posts—especially towards the middle—were no doubt appreciably taller than others. How they were arranged it is impossible to say, but the excavation produced fragments of charcoal from small branches that the excavator interpreted as possibly indicating a wattle and daub arrangement. This fits very well with the idea of a curtain of timber through a gap in which observation of the first glint of the rising midwinter Sun was seen, in a way that will be explained.
FIG. 41. Plan of the area around the façade of the Skendleby 2 long barrow. An observer in the front ditch, looking over the façade in a direction originally marked with four stakes, saw the setting of Deneb. Note the north–south and east–west directions to the corners of the façade from the observer. An observer at the gap could observe the setting Sun at its midsummer extreme, along line 1. Line 2 is the sight-line towards the midwinter rising Sun from the ditch at the northwest (see Fig. 40).
The line of four posts meets the backfilled ditch at its very centre, and there are two equally spaced parallels to it that graze the holes for the large D-posts in the burial area and bring us to the corner of the (original) end-ditch. Over a natural treeless horizon, midwinter sunrise was at altitude 0.57° and azimuth 132.7°, and midsummer sunset at an altitude 1.44° and azimuth 311.6°. From a point near the northwest corner of the original back ditch (see Fig. 40), the Sun would have been observable at its midwinter extreme along the line marked 2 in the figure, grazing one of the burial split trunks and one side of the gap in the façade. The burial post would have covered the solar image as it rose, being about 10 per cent larger in angular diameter. The first glint of the Sun’s image would thus have been trapped between two posts, almost (but not quite) in a manner that was to become classic over the following two millennia. Midsummer sunset was similarly observable by an observer looking along the line of sight marked 1. The posts flanking the gap in the façade were unusual, as it happens, in that they had flattened faces to the inside. It was easy to follow the rising Sun, by shifting one’s own position slightly, opening and closing the slit at will. The angular width of the D-post was well matched to that of the Sun, as seen from the end-ditch, being about 10 per cent larger. From the façade, of course, the post was nearer and the margin much greater.
While we do not have a ditch section at the observer’s position—a high priority for any future excavation—we do have one not far from the centre that offers support for the claim that the end ditch was used for solar observation. As shown in Fig. 42, a ledge there—had it been used for viewing—would have brought the observer’s eye to the same level as the top of the posts over which the setting of Deneb was observed. Given no other obstacle, in other words, the observer can see perfectly well down to the natural horizon. This suggests solar viewing, since no star, not even Sirius, is visible down to that level (0.57° without trees). Observations would have been made by someone standing at the point described, but level with the step and at the inside edge of the ditch—in fact more or less at the old ground level.
FIG. 42. The front