Following the movement of a shadow during the day is a way to track time. Try it yourself by making a sundial. A very long time ago (long before there were digital clocks and mobile phones), people ...

WE have received a small portable sundial of ingenious construction, made of aluminium (“Kosmos-Sonnenuhr”. Stuttgart: Franckhesche Verlags-handlung). The workmanship is neat and attractive, and the ...