👑 350 years ago today on 22 June 1675, a royal warrant from Charles II ordered the building of the Royal Observatory in Greenwich. 👑 He had been persuaded by leading scientists that building an observatory would bring Britain closer to working out how to determine longitude at sea - a breakthrough that would boost the country's trade prospects by making global navigation easier, safer and more efficient. 👑 Over the next three and a half centuries, numerous scientific discoveries and advanceme