I too watch the programme and remembered using a similar method when making a type of mortise and tenon joint in wood at school. In this case a wedge is used to splay the tenon apart as it is pushed into the mortise giving a very tight joint that did not require pining or glueing.
This then made me wonder if this method could have been used fix together the many wooden structures instead of wooden pins or rope.....just a thought :o)

"I was watching 'Standing with Stones' at the weekend, and in it Mr Soskin was going on about the mysterious long slot holes in the Stones he was looking at. Somewhere or other. "

I've got the DVD Rhiannon, it was'nt Wales or the South West which I looked at yesterday, so it must have been one of the other chapters, will check for you.. that roman one was a very skinny slot, you're sure they (neolithic/bronze) would have been capable of creating a deep thin slot?.
Actually I got sidetracked by the outtakes, they are incredibly funny;

Hi Rhiannon,
Amazing isn't it? I've asked loads of archeos what they think of the slots and not a single one has even mentioned a Lewis. It's a new one on me too so a big thank you for the pointer.

It does open up more questions. The main reason I dismiss their use as 'unfinished splitting' is that those at Fernworthy and Castleruddery are situated in similar positions within their circles and there are no other seemingly redundant stones. It seems almost impossible to me that each site would contain a single slotted stone, identical in number of slots, that did not serve some specific function.

I have to say that, if the slots were for hoisting I think they would be even more numerous than they are but it certainly adds another possibility.

Best wishes

Rupert