The notch is nice. But it doesn't point to it at exactly midday, isn't that more what you'd expect if it was being used (being chipped out at great effort) for a deliberate marker, not at quarter to? At midday nothing particularly obvious seems to be happening. I would say 'well quarter to is near enough' but the patterns obviously change quite a bit between quarter to and noon?
just an observation.
If the Closure Stone was upright instead of being over 21" out of kilter like it is, the 'reading' would have been entirely different. I find it very difficult to believe that this most important and centralising orthostat was originally set in so much out of upright. In fact I know it wasn't because it has moved since last year! Look aound the remaining structure carefully and see how it is out of shape. Look at just the photos shown to see how the Capstone is way off centre to the main orthostat now and lurches badly to the left. I'll post a photo of the rear of the structure shortly to show you what I mean.
Here it is Rhiannon,
The rear right-hand stone (in my opinion) is not the original, that is elsewhere and patently obvious where to my mind. I believe that rear right stone to be the rear closure as it is the only one that fits. Can't say any more at this moment as it's part of my private research which is ongoing but I have them all sorted now I believe. To gauge the degree of sideways tilt on the Capstone just look at the level line of the ridge on the house. By replacing the uprights in the correct order you get a level sideways plane which would make modern 'readings' completely adrift from what you get today. That's my opinion anyway. I have no doubt in my mind that Trethevy Quoit has undergone drastic 'surgery' during the 5,000 years+ it has stood there. But as always nothing can be proven 100% so we have to rely on a bit of common sense taking over. This is a chambered tomb we are looking at, nothing else.
On saying that there is no reason why somebody should not come along after the build and put forward other ideas but in the main they will be incidental and only work for some of the claim not all. http://i26.servimg.com/u/f26/16/16/85/69/p1010013.jpg