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Zooming in on conservation: the treatment of a 17th century telescope

This beautiful 17th century telescope needs careful treatment before going on display. Object Conservator Rachel Roberts eyes up the issues

The lost chronometer: the timepiece that sailed with Charles Darwin and Sir John Franklin

Learn more about the marine chronometer that journeyed on board HMS Beagle before being lost at sea during Sir John Franklin's disastrous expedition

Early charts from the Mediterranean

The Caird Library and Archive’s display case highlighted three colourful charts from the rich cartographic collection of Royal Museums Greenwich.

True north and magnetic north: what's the difference?

In September 2019, for the first time in over 360 years, compasses at Greenwich pointed true north. But what does this mean - and haven't compasses always pointed 'north'?

What is longitude?

Find out what longitude is and what makes it so hard to measure

What made the search for longitude so important?

Why did most of the great European powers offer huge rewards for a way to determine longitude at sea?

Longitude found: Nevil Maskelyne and the lunar method

Find out how the celebrated Astronomer Royal helped to solve the longitude problem

Longitude found - the story of Harrison's Clocks

Who was John Harrison, and how did his clocks help to solve the problem of finding longitude at sea?

What is the Prime Meridian and why is it in Greenwich?

How Greenwich found its place in the centre of global time and navigation

Time

Time and navigation