1812 - aged 12 began working on construction of Göta Canal. 1824 - built his first hot air “caloric” engine. 1826 - moved to England and formed partnership with John Braithwaite. 1829 - built steam engine, 'Novelty', with John Braithwaite. 1836 - patented the marine “screw” propeller. 1839 - moved to US. 1848 - became US citizen. 1868 - built a rotating solar observatory on the roof of his Manhattan town house.