Look along the posts: https://timdaw37.github.io/bulford-posts-3d/
Set Midwinter, Sunset, Full orb. Then Midsummer, Sunrise, First gleam. The question is which of those two pictures you trust.
Stonehenge has the same argument. The axis works both ways, and for a generation the tourist photograph has been midsummer sunrise up the Avenue. Parker Pearson and others have put the weight on the other end: you walk in from the north-east and watch midwinter sunset drop through the Great Trilithon. Ruggles has been careful to say the architecture is precise enough to pick the solstice in space, and that first or last gleam is the closer convention, not that one festival owns the monument.
Harding, Leivers and Silva, in PAST 113, publish the Bulford posts as a solstitial pair — midsummer sunrise and midwinter sunset, about 120 m apart, around 2950 BC. Harding found the two structural pits first and only then asked what they pointed at. That is the right order. The question here is only which way the line is better.
The 3D model is the published plan, not the Wessex GNSS. From that plan the posts run 48.31° / 228.31° true. On Bulford’s own skyline, 2950 BC, the six like-for-like events are:
| Event | Convention | Azimuth | Miss from the posts |
| Midwinter sunset | Full orb | 228.55° | +0.23° |
| Midsummer sunrise | First gleam | 48.90° | +0.58° |
| Midwinter sunset | Half orb | 229.03° | +0.72° |
| Midsummer sunrise | Half orb | 49.29° | +0.97° |
| Midwinter sunset | Last gleam | 229.53° | +1.22° |
| Midsummer sunrise | Full orb | 49.72° | +1.41° |
Full orb at midwinter sunset is the closest of the six — a quarter of a degree, inside a solar radius. First gleam at midsummer is next, half a degree, one disc. The rest are worse.
Two warnings, which do not cancel the table.
You must not mix conventions. First gleam at one end and full orb at the other are different ways of watching. If the same limb is used both ways, winter last gleam is worse than summer first gleam. Reciprocity was never going to give a second bullseye on one straight line: refraction and the solar radius push rise and set apart, and the south-west horizon is not high enough to cancel that.
The picture also flatters the winter disc. The south-west skyline is a local rise at about 880 m, so the sun sitting on it looks planted. The north-east gleam is 5.7 km out. Your eye and the azimuth are not quite the same measurement.
Ruggles’ published rule of thumb is that claimed sightlines of half a degree and better in the old lists were the ones most easily explained as selection, that British prehistoric orientations show no evidence of precision much greater than about 1°, and that a couple of degrees is still a fair orientation in a group of sites (Ruggles 1984, 304–306; 1997, 207). On that scale the midwinter full-orb miss is allowed, the midsummer first-gleam miss is allowed, and neither is a prosecution. A single pair in a crowded pit field still has to beat coincidence.
We do not have the GNSS. Two independent digitising jobs of the PAST plan agree to 0.2 m, which is inside the pit and not the solar miss. The miss may move when the survey comes out. Until then, the model says: if you have to pick one, pick the sun standing on the south-west ridge at midwinter.
Have a go with the table in one hand and the model in the other.
Harding, P., Leivers, M. and Silva, F. 2026. A newly discovered solstitial post alignment in the Stonehenge landscape at Bulford. PAST 113, 2–5.
Ruggles, C.L.N. 1984. Megalithic Astronomy. BAR British Series 123. Oxford.
Ruggles, C.L.N. 1997. Astronomy and Stonehenge. Proceedings of the British Academy 92, 203–229.
Ruggles, as well as the late Timothy Darvill are correct. The monument celebrates many things. However, all interrelated.
ReplyDeleteFor instance multiply the 56 Aubrey markers by 12, making 672 even divisions. Marching 672 lunations anticlockwise, starting on hole #56, one would wheel back to #56, 672 full moons later. At 669 lunations one would be inline with the Great Trilithon. Three quarters of the way from marker #1 to #56. If one halved the 669 lunations, one would again be inline with the great trilithon at 334.5 lunations. Once the wheel is turning, it would be hard to stop. For whatever “reason” science has forgotten the Yin and Yang of 334.5 and 669 lunations. They interrelate. Not one is a start nor an end. The interrelationship understanding is what is monumental (and forgotten).
I also imagine, if clans were to spend many days at the monument during important celestial events, they had time to explore. I hypothesize they might have camped in traditional areas. Separate from other “tribes”. Year after year, hence the barrow groupings. There is no reason why other things wouldn’t be studied, celebrates, explored, in other parts of the landscape, at different points in time. I wouldn’t mind retrieving a arrow head I left behind, as I heard now it is pink. Mabe dig a deep pit. Explore the sky at Woodhenge, etc.
Tim, I finally managed to comment by using a different browser, Firefox doesn't work for me on this website. Anyway, here's my comment drafted earlier:
ReplyDeleteAlignment as per 3D Model: 228.31
From Stellarium(David Hoyle) @ MWSS, 2950BC:
Full Orb(FO) - 229.1245 (+0.8145)
Last Gleam(LG) - 230.0168 (+1.7068)
Alignment as per 3D Model: 48.31
From Stellarium(David Hoyle) @ MSSR, 2950BC:
First Gleam(FG) - 48.9604 (+0.6504)
Full Orb(FO): - 49.7791 (+1.4691)
Averages:
(MWSS_FO+MSSR_FG)/2 = 0.73245
(MWSS_LG+MSSR_FO)/2 = 1.58795
Alignments (see 1 below):
To MWSS(FO) = (229.1245-0.73245) = 228.39205
To MSSR(FG) = (48.9604-0.73245) = 48.22795
Altitudes FO:
MWSS = 0.69
MSSR = 0.64
1) In terms of conventions, coupled to practicalities of observing the sun, full orb at MWSS is when the sun begins its entry into the "underworld" and first gleam at MSSR is when the sun begins its exit from the "underworld".
2) Building a reverse model from the most accurate horizon available (David Hoyle, https://www.standingstones.org/viewer.html?name=bulford-neolithic-pits-and-alignment_su1739043550&country=uk&year=3750&grid=None&res=Med&zoom=10&x=86.9364161849711&y=20)
I took the observation location as being approximately at the centre between the two post holes. From here the horizon altitudes are almost equal at 0.69 deg. to MSSR, and 0.64 deg. to MWSS as measured by full orbs on the horizon, hence mid-sun values.
The post alignments from this location, and averaging the results, come out as 48.22795 deg. to MSSR, and 228.39205 deg. to MWSS. A straight line alignment would then average 48.31/228.31.
3) One could speculate that this setup was potentially capable of being created and used for scientific observation within what might have been an otherwise important location for ritual/cultural purposes. Equally, the site might have been purely an educational setup to research the rises and sets of both the sun and the moon and their relationships.
The discoidal knife could equally be symbolic of either or both of the sun and the moon.
4) As an educational/research setup and from a central observation point, the speculation can be made that each post could have had an artificial horizon attached by way of a horizontal wooden slat, or similar, against which the respective sunsets and sunrises would have been observed and all four limbs of the sun and moon marked onto the posts and artificial horizons.
From this centre, at approximately 60 metres to posts of 0.5 meter diameter, this would represent a field of view of approximately the sun/moon diameter. In short the sun or moon would be hidden behind each post at some time during respective sets or rises. The metric of 120 metres/0.5 metres gives a result of 240, which in seconds is the time it takes the sun to travel one degree on its orbital plane. perhaps indicative of knowledge at the time.
Conclusion:
As a research setup the precise on-horizon alignments aren't crucial at this location, rather both directions offer reasonably level horizons against which artificial horizons on the posts offer practical observation opportunities.
The key question - is this too sophisticated for post-Avebury and pre-Stonehenge? Perhaps our archaeological mindset is the barrier going by the assumptions in the PAST 113 pdf.