OK all you fellow carpenters and anyone else who think they know.
Here is a photo of one nail which has been just tapped into a piece of scrap timber with 10 other nails laying at it's base. The nails in question are 65mm flat heads.
The task is to balance the 10 nails on top of the one standing . No magnets, electricity, glue of any kind are used and provided it is not too windy if done out doors, it can be done anywhere. All you need is a steady hand. I have the photo of the nails balancing, but haven't uploaded that photo anywhere yet, so It's no use looking !
I will post a pic of the answer in a day or 2 time. Have fun !