Caleb’s List (The Arthur’s)

This post doesn’t really relate to snow, but has everything to do with mountains in Scotland.

There’s been a bit of noise recently about Kellan MacInnes‘ book: Caleb’s List. This details the hills that Caleb George Cash could see from the top of Arthur’s Seat, back in 1898 and Kellan’s journey climbing them all. BBC Out of Doors did a feature on Kellan and the list a couple of months back and the Mountaineering Council of Scotland have also mentioned them.

So I thought, why not work it out? What’s visible from Arthur’s Seat? To do this I used the GIS GRASS and a digital elevation model (DEM) from the Ordnance Survey called Panorama (this was before Terrain 50 came out – I’ve just taken a while writing it up!). After loading the Panorama DEM into GRASS I opened the line of sight tool (r.los) and keyed in the Arthur’s Seat coordinates. I left the viewing height as default (1.75 m above the summit) and set the program going overnight with a maximum viewing distance of 200 km. This last part means it will look in a 200 km radius around Arthur’s Seat for all points that aren’t obscured by something higher in between. I used my work/uni computer for the analysis (8 Gb RAM, quad core Intel i5-2400 @ 3.1 GHz).

Coming back in the next morning and my machine had churned through a woefully small amount of the processing! I stopped it and ran it with a maximum viewing distance of 150 km. This still took a fair time to complete, but made much quicker headway than the larger extent.

You can see the results below, plotted up using QGIS (I’ve included Munros for comparison):

Visible area from Arthur's Seat, within 150 km

Visible area from Arthur’s Seat, within 150 km

What’s surprising is that there’s a clear line of site as far afield as Northumberland, Ben Cruachan and the Cairngorms! This doesn’t mean you can see these from Arthur’s Seat though… likely visibility isn’t often good enough.

If you’d like to see the above in more detail (with OS 250k background map), you can download it from my cloud storage.

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