When King Charles II signed the royal warrant that led tothe founding of the Royal Observatory in 1675, it was to ensure that Britainwas not left behind other European nations as they pursued global trade andresources. Now, in its 350th year, the 'small observatory within our park atGreenwich' is perhaps the most famous such institution in the world, home tothe historic Prime Meridian of the World, 0 Degrees longitude, and an essentialreference on our clocks, watches, maps and globes. The 100 objects contained within the pages of this bookhighlight the many people, ideas and technologies that contributed to'perfecting the art of navigation' and mapping the stars. They include some ofthe most famous objects in the Royal Observatory's collection, like JohnHarrison's pioneering timekeepers, the Great Equatorial Telescope and theShepherd Motor Clock, along with lesser-known items that document how our ideasabout time and space have changed over the centuries. Instruments, photographs, plans and archival documents tellthe story of the Royal Observatory from its early days as Britain's firststate-funded purpose-built scientific institution, through periods of rapidscientific and social change, all the way to its twilight years at theforefront of astronomical research in the first few decades of the twentiethcentury. Today, the Observatory is once more a working observing site but alsoa heritage centre and home to London's only planetarium, seeking to inform andinspire with stories of discovery, innovation and wonder.