History

1/2) An incredible Roman portable sundial. This ingenious device was the precision pocket watch of its day, telling the owner the time wherever they were in the Roman empire. The vertical disc sundial could function in a range of latitudes; first the user set their location by... pic.twitter.com/hZi8Xrsvlx

— Gareth Harney (@OptimoPrincipi) May 1, 2024