Principal triangulation point for Northern Scotland

[Morecambe Monkey]

On a recent trip to Glen Affric,one of the walks i took in was a long day to bag the Munros Carn Eige,Beinn Fhionnlaidh & Mam Sodhail. While i was researching routes for the walk it came to my attention that apart from the primary trig on Carn Eige,the huge hollow cairn on Mam Sodhail was itself built by the Ordinance Survey & used as the principal triangulation point for the initial mapping of Northern Scotland in the 1840's. I was just wondering if there was any reason why it wasn't included on this website? Not in any way a critisism,as in the 4 plus years i've been using this site,i've found it to be a superb & enjoyable sourch of info.

Cheers MM.

[agentmancuso]

Very interesting, I doubt many people here knew that. But the simple answer is that T:UK generally lists stations that formed part of the Re-triangulation of Britain that started in 1936 (often referred to as OSGB36). Earlier OS operations are not so well documented unfortunately.

[Morecambe Monkey]

Ah i see,that makes perfect sense. Thought the date was a tad early. Thanks for your reply,much appreciated.

[peregrinus]

On a recent trip to Glen Affric,one of the walks i took in was a long day to bag the Munros Carn Eige,Beinn Fhionnlaidh & Mam Sodhail. While i was researching routes for the walk it came to my attention that apart from the primary trig on Carn Eige,the huge hollow cairn on Mam Sodhail was itself built by the Ordinance Survey & used as the principal triangulation point for the initial mapping of Northern Scotland in the 1840's.

If there's evidence for this, would it be valid to add Mam Sodhail as an Old Trig (with summary of evidence in log)?