I watched a compelling programme on BBC Four last night in which Stephen Fry learnt about the Gutenberg printing press, and some very enthusiastic history and carpentry chaps recreated the first press itself. The way this machine was constructed is truly incredible - and the method used to make the twin thread for the screw, ingenious.

Did you see it?! If you missed it on the TV, with the very latest in modern technology, for the next six days you can watch it here on BBC iPlayer. Genius.