chinese Invention Helicopter
mohamed and kalei
The Helicopter Rotor and the Propeller: China, Forth Century CE. By fourth century CE a common toy in China was the helicopter top, called the 'bamboo dragonfly'. The top was an axis with a cord wound round it, and with blades sticking out from the axis and set at an angle. One pulled the cord, and the top went climbing in the air. Sir George Cayley, the father of modern aeronautics, studied the Chinese helicopter top in 1809. The helicopter top in China led to nothing but amusement and pleasure, but fourteen hundred years later it was to be one of the key elements in the birth of modern aeronautics in the West. http://asiasociety.org/education/resources-schools/elementary-lesson-plans/chinese-inventions
China, Russia boost military cooperation.