The most significant pre-Wright brothers aeronautical experimenter was the German glider pioneer Otto Lilienthal. Between 1891 and 1896, he built and flew a series of highly successful full-size gliders. During this period, Lilienthal made close to 2,000 brief flights in 16 different designs based on aerodynamic research he conducted in the 1870s and 1880s. Like the example in the National Air and Space Museum collection, most were monoplanes with stabilizing tail surfaces mounted at the rear. Control was achieved by shifting body weight fore-and-aft and from side-to-side.