Ships, Clocks and Stars: The Quest for Longitude

23 Jul 2014
Written by
Richard Dunn
Photo: Royal Museums Greenwich

2014 is the year Royal Museums Greenwich celebrates an important scientific breakthrough with its major new exhibition, Ships, Clocks & Stars: The Quest for Longitude.

Finding the longitude was one of the triumphs of the Georgian age, largely thanks to the impetus provided by the Longitude Act of 1714. The Act sought to encourage people – anyone – to answer a challenge previously considered impossible: coming up with a practical method for finding a ship’s longitude at sea. And, eventually, it worked. It’s no surprise, then, that the Longitude Prize 2014 has been set up to commemorate what is often seen as a model of how incentives can encourage innovation in science and technology.

The story we’re telling in Greenwich begins in the 17th century, when the expansion of long-distance sea trade provided ample reason to tackle one of the great seafaring challenges – knowing your ship’s longitude or east-west position. Latitude (north-south position) was quite easy to measure, so this was the missing link in accurately fixing a ship’s position and navigating efficiently.

A challenge that captured the imagination

How to find longitude was understood in theory; it was doing it on a ship in the middle of the ocean that was proving impossible. To encourage new thinking, the Longitude Act offered life-changing rewards of up to £20,000 (several million pounds today) for methods that worked. Longitude became the talk of London’s coffee-houses and captured the imaginations of astronomers, artisans, politicians, seamen and satirists.

Ships, Clocks & Stars tells the story of how two schemes – one mechanical, one astronomical – finally solved the longitude problem. To do so, it brings together a range of wonderful objects. Some, like John Harrison’s famous timekeepers, are well known but still hold an extraordinary fascination. Others will be more surprising. You may never have wondered what an 18th-century astronomer wore at night – this is your chance to find out. You can also see the original Act that inspired so much inventive creativity.

Ships, Clocks & Stars makes use of the latest exhibition techniques to immerse visitors in the story, helping them understand what it was all about and appreciate why it mattered. How could a clock or the Moon help you find where you were, and why were these ideas so difficult to use in practice? How did coffee-loving Georgians react to the countless schemes offered in pursuit of the great rewards? And how did the ultimately successful methods become part of daily life at sea and change how we understood the world?

Beyond the horizon

In a year when celebrating the 300th anniversary of the 1714 Longitude Act has prompted us to think about the global challenges of the future, we hope that Ships, Clocks & Stars will get visitors thinking about how science, politics and commerce have worked together in the past.

We hope they’ll enjoy themselves at the same time. We’re also using it to open up the conversation, asking visitors what they think today’s ‘longitude problem’ is, just as the Longitude Prize 2014 has done. Their responses could be surprising.


Join the conversation on Twitter, with the hashtag #WhereOnEarth

Ships, Clocks & Stars: The Quest for Longitude is at the National Maritime Museum, Greenwich, until 4 January 2015.

Richard Dunn is Senior Curator and Head of Science and Technology at Royal Museums Greenwich. He and Rebekah Higgitt are the curators of Ships, Clocks & Stars and authors of Finding Longitude: How Clocks and Stars Helped Solve the Longitude Problem (Collins, 2014).