When King Charles II signed the royal warrant that led to the founding of the Royal Observatory in 1675, it was to ensure that Britain was not left behind other European nations as they pursued global trade and resources. Now, in its 350th year, the 'small observatory within our park at Greenwich' is perhaps the most famous such institution in the world, home to the historic Prime Meridian of the World, 0 Degrees longitude, and an essential reference on our clocks, watches, maps and globes.

The 100 objects contained within the pages of this book highlight the many people, ideas and technologies that contributed to 'perfecting the art of navigation' and mapping the stars. They include some of the most famous objects in the Royal Observatory's collection, like John Harrison's pioneering timekeepers, the Great Equatorial Telescope and the Shepherd Motor Clock, along with lesser-known items that document how our ideas about time and space have changed over the centuries.

Instruments, photographs, plans and archival documents tell the story of the Royal Observatory from its early days as Britain's first state-funded purpose-built scientific institution, through periods of rapid scientific and social change, all the way to its twilight years at the forefront of astronomical research in the first few decades of the twentieth century. Today, the Observatory is once more a working observing site but also a heritage centre and home to London's only planetarium, seeking to inform and inspire with stories of discovery, innovation and wonder.