Monday, 2 May 2011

The Benchmark

Hidden in the Victorian brickwork on the corner of this church is an endangered species. This is a cut benchmark, it is a height datum used by surveyors for the Ordnance Survey when creating maps of the UK.

There used to be hundreds of thousands of these marks, often placed on churches or public buildings that the surveyors felt would be there for a long time. Of course these days surveying is done by GPS, by Radar and Lidar using a host of space age methods that would have seemed like Dark Arts to the Victorian Surveyors.

Just imagine: Being able to summon a measurement of your position out of thin air! Even though I work in the world of electronics I still find the function and accuracy of GPS extremely hard to believe...



It is these modern methods that spell the doom of the humble cut benchmark. They are no longer needed or maintained, so one by one they are being overgrown or demolished as new buildings replace old ones. It was nice to meet one hiding in this Hampshire churchyard 

So if someone offers to benchmark your computer, just check if they are holding a chisel...

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