Otto Lilienthal, a pioneer of German aeronautics, was interested in the relationship between lift and aerodynamics. From 1891 onwards, he made more than 2,500 glides from a hillside near Berlin using his own inventions. He built 16 machines made of willow wood and cotton canvas with a surface area of 10 to 20 m2, closer to the hang glider than the glider. His dream of flying was shattered in 1896 when his glider crashed from a height of 20 metres. Lilienthal succumbed to his injuries the next day. His research into 'heavier-than-air' machines inspired future aviation pioneers, including the Wright brothers.