… and Christmas trees were tall … one of the odd things we learned at primary school was the purpose of bench marks. The school was split between two locations with only one canteen so, every lunch time, we were marched in pairs down to the lower school; a hungry chattering snake. Carved into a wall near the end of the route was a bench mark – I have never been good with remembering the abstract but because there was a tangible example nearby, the lesson stuck.
With the advent of more sophisticated mapping techniques these old marks have fallen into disuse. This explanation is from the Ordnance Survey website:
Ordnance Survey Bench marks (BMs) are survey marks made by Ordnance Survey to record height above Ordnance Datum. If the exact height of one BM is known then the exact height of the next can be found by measuring the difference in heights, through a process of spirit levelling.
Most commonly, the BMs are found on buildings or other semi-permanent features. Although the main network is no longer being updated, the record is still in existence and the markers will remain until they are eventually destroyed by redevelopment or erosion.
Bench marks are the visible manifestation of Ordnance Datum Newlyn (ODN), which is the national height system for mainland Great Britain and forms the reference frame for heights above mean sea level. ODN is realised on the ground by a network of approximately 190 fundamental bench marks (FBMs). From these FBMs tens of thousands of lower-order BMs were established. The network has had little maintenance for 30 years, and in some areas (mining areas for example), subsidence has affected the levelling values. In these regions the BMs cannot be relied upon to accurately define ODN.
When outdoors for a walk along the local lanes yesterday I came across this example on a local farm gate:
Following some extensive online time-wasting, I found there was a Bench Mark Database – a trainspotter’s delight! Even more exciting, this bench mark was not registered but, it is now – Beaufront, Gatepost 3 – not exactly my own star but an acceptable, humble alternative 🙂
that’s interesting, I will look for some bench marks now here too :o) we sadly have no database :o(
It would be interesting to know how extensive these types of mark are across Europe. A database for such things strikes me as peculiarly British – the sort of thing only an ex-trainspotter could get excited about. I am an ex-trainspotter 🙂
I always looked for such a database, we have so much bench marks and stones with carvings and I would like to know more about the meaning :o)
I am familiar with, and have spotted benchmarks from time to time in the past…but a database?!
Who’d a thought it – I will now be spotting the others around our lanes 😀
Woah, a database of benchmarks? You did your good deed for the week by adding this one, little soldier. 😉
Even worse, I am now on a mission to find more 😀
Wonderful, Robin ! – now you have a Quest !
I loved the Bee Gees. I don’t know why thinking about them is so sad … I suppose it’s because they led such strangely unfinished lives.
One of my more innocent, cheaper pastimes. I think I might tire of it quite quickly 🙂
“… strangely unfinished lives …” – exactly right. The video of the young Robin and Barry is particularly poignant, almost as though it were made with stardom in mind. I was never very keen on their later disco phase (not cool enough :-)) but I think Odessa, as a concept album, is up there with Sgt Pepper.
Have a grand weekend, R
Saturday not so hot: the party I don’t support won the NSW elections. But today on telly is the grand final of World Cup cricket: Oz vs the Kiwis ! I love ’em; so that even if they beat us, I shan’t be all that cast down. 😀
Coverage of the World Cup is very low-key in the UK – I wonder why 🙂
Wow – thanks for this fascinating lesson – and how nice that you have contributed your shot to the legacy!
A pleasure and many thanks for stopping by.
When I was small my friends and I were obsessed with Secret Seven stories about spies. We trailed an old woman who had hair on her chin, thinking she was a spy in disguise. She obliged us by sitting on a bench and throwing away an Embassy packet. Geddit!!! We were confirmed in our suspicions, we felt.
We then followed her to a corner which had a bench mark on it and we thought this was where she might be making a reconnaissance. Poor old soul. Talk about witch hunts.
So , yes, bench marks have always intrigued me.
Excellent story – is it memory playing tricks or was there once many more scary old ladies about. Without wishing to plug Golf in the Wild ( 🙂 ), I talk about this in the book. There was one old lady in a brown mac and beret who used to frighten me witless. Bench marks didn’t come into it but she had some very strange habits.
Thanks for stopping by and the splendid comment.
There is one of my poems called What MI6 Didn’t Tell Us in the Poetry section of my site ( March 2013). It mentions the episode I described-and benchmarks in particular! You might enjoy it…
Thanks for that, I will go and have a look.
You had me singing along from the word go and I love the photo, too, Robin. I shall pay more attention in future. 🙂
Thanks Jo, wonderful track isn’t it. I had some trouble accessing your latest posts in the Reader – I will go back and try the direct route (hence the silence from me).
I’m diverting from yours to M-R and then coming back, Robin. I’m happy that WP only victimise me occasionally 🙂
You write so well, Robin. So poetic… I really like the image too!
That’s very kind Makin.
My submission for silence will follow tomorrow – a bit of struggle that one 🙂 ❤