The Horse Collar: China. Third Century BCE. About the fourth century BC the Chinese devised a harness with a breast strap known as the trace harness, modified approximately one hundred later into the collar harness. Unlike the throat-and-girth harness used in the West, which choked a horse and reduced its efficiency (it took two horses to haul a half a ton), the collar harness allowed a single horse to haul a ton and a half. The trace harness arrived in Europe in the sixth century and made its way across Europe by the eighth century.
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.
The Kite: China, Fifth/Fourth Century BCE. Two kitemakers, Kungshu P'an who made kites shaped like birds which could fly for up to three days, and Mo Ti (who is said to have spent three years building a special kite) were famous in Chinese traditional stories from as early as the fifth century BCE. Kites were used in wartime as early as 1232 when kites with messages were flown over Mongol lines by the Chinese. The strings were cut and the kites landed among the Chinese prisoners, inciting them to revolt and escape. Kites fitted with hooks and bait were used for fishing, and kites were fitted with strings and whistles to make musical sounds while flying. The kite was first mentioned in Europe in a popular book of marvels and tricks in 1589.