Prismatic Compass

Silva Compasses (and subsequent GPS) seem to have taken over from Prismatic Compasses but when I learnt map navigation in the CCF at school these were what we used.  

They have a lovely chunky feel to them and I love them.

I was therefore delighted when we found this in Jane's Dad's house when we were clearing it.  I think it was the one he used in the war when he was part of the 8th Army in North Africa.