Alexander von Humboldt (1769-1859) is the great lost scientist: more things are named after him than anyone else. There are towns, rivers, mountain ranges, the ocean current that runs along the South American coast; there's a penguin, a giant squid - even the Mare Humboldtianum on the moon.
His colourful adventures read like something out of a Boy's Own story: Humboldt explored deep into the rainforest, climbed the world's highest volcanoes and inspired princes and presidents, scientists and poets alike. Napoleon was jealous of him; Simon Bolívar's revolution was fuelled by his ideas; Darwin set sail on the Beagle because of Humboldt; and Jules Verne's Captain Nemo owned all his many books. He simply was, as one contemporary put it, 'the greatest man since the Deluge'.