The intentions of Alexander von Humboldt, who set out into the world at 27 after the death of his mother in 1796, make the aspirations of today’s gap-year travellers look pretty lame. According to Nathaniel Rich, reviewing a new biography of the great man for The New York Review of Books, “He would analyze everything, from wind patterns and cloud structures to insect behaviour and soil composition, collecting specimens, making measurements, and taking temperatures. He wanted no less than to discover how ‘all forces of nature are interlaced and interwoven.’ He took as the premise of his expedition that the earth was ‘one great living organism where everything was connected.’”