300th Anniversary of the Longitude Act

Maritime museum finds time for celebration of Harrison’s sea clocks

The exhibition marks the 300th anniversary of the Longitude Act, passed in 1714, which established the Longitude Board and offered a vast £20,000 prize to anyone who could solve the problem of measuring longitude at sea. It includes the actual act of parliament, passed in the last weeks before the death of Queen Anne, on display for the first time.

The story of John Harrison, the carpenter and self-taught genius clockmaker who invented a series of ever more accurate clocks and then a cabbage-sized watch that solved the problem, but never got the full prize from the board, inspired Dava Sobel’s bestselling book and film, Longitude.

This is the reason why my job (making atomic clocks — real clocks) is a navy job — precise navigation requires precise time. The transition to GPS hasn’t changed that fact. Poor navigational ability is costly:

In a storm in 1707, when an entire British fleet was driven onto the rocks at Scilly believing they were safely out at sea, more than 1,400 sailors drowned.

More: Why longitude mattered in 1714