# johnharrison chronometer timeball stemlearning friday meridian royalobservatory greenwich london weekend

John Harrison's H4 chronometer was pivotal in maritime navigation. He is one of the main topics in our interactive STEM pod, as together, his invention and the Time Ball revolutionized sea travel and safety!

7 16
2021-02-03

Happy Friday!
~Weekend visit suggestion~ (°-°)/
If you are in Greenwich (London) visit the Prime Meridian, based at the Royal Observatory! Where the time starts (in a human way) \(°-°)

0 1
2018-02-23