...THIS is a sundial.
Or "Don't stand just there at noon."
Thinking back on last year's big trip, one of the stand outs was the Musée des Arts et Metiers (previous posts here and here) and this is one of the items from the first gallery of instruments.
I don't recall what it is, but I reckon it's pretty ace. I mean - with one of these in the [stately home] garden you should be able to pull off a top notch locked-room mystery, no problem, and shoot the Pope while proving the curvature of the earth. Your only problem was going to be coming up with something better and teaching the butler to load it while keeping clear of the barrel.
I'd like to thank Greg for making sure we didn't miss this. With the Pitt Rivers Museum, it's one of the great 'secret museums' of the world.