How Britain Built the Impossible Bell Rock Lighthouse in 2 Hours a Day
Bell Rock Lighthouse: a 36 metre tower standing on a reef 18 kilometres off the Angus coast that is underwater for most of every day. Between 1807 and 1810 the masons had the rock available for about 2 hours at each low tide, and only in summer. They placed around 2,800 interlocking blocks in 90 courses, with the lowest 9 metres built solid all ...