Paris meridian. Really I just liked the look of it.
When I moved back to the UK it went missing, and I assumed it was lost for good. But we have been taking a load of boxes out of the loft for sorting, and it has turned up again, along with a lot of other bits and bobs.
On the back it says "Stanley London, 1935". There is a folding prism on the side, which is obviously for taking bearings, but until this afternoon I hadn't managed to figure out how to use it.
A lost compass was never much help, and I don't suppose a found one is going to get a lot of use either. But it's nice to have it back.