2.2K views · 26 reactions | #OnThisDay 1955: At the National Physical Laboratory, scientists built the world's first atomic caesium clock. | BBC Archive | Facebook

#OnThisDay #OTD 1955 Scientists at the National Physical Laboratory in London completed the world's first caesium atomic clock. The very first accurate atomic clock was built in the UK at the National Physical Laboratory in London. Louis Essen and Jack Parry were the two physicists who built it. | BBC Archive