A hand-carved wooden clock that scribes the time on a magnetic board
by Cory Doctorow from on (#15GHG)
https://www.youtube.com/watch?v=WEbmYp5VVcw&feature=youtu.be
Suzuki Kango carved over 400 wooden parts for his senior thesis exhibition project: it uses "four magnetic stylus pens on a magnetic drawing board to mechanically write the full time every minute in 24-hour format."