Here are some of the most celebrated mechanical inventions from China that have exerte Mechanical d profound influences on the development of other societies, especially when they were passed to the West:

铸铁 Transcription: zhù tiě Translation: Cast iron
活塞风箱 Transcription: huó sāi fēnɡ xiānɡ Translation: The double-acting piston bellows
平衡环（被中香炉） Transcription: pínɡ hénɡ huán ( bèi zhōnɡ xiānɡ lú ) Translation: The gimbals (as in the ancient Chinese incense Burner)
链泵 Transcription: liàn bènɡ Translation: The chain pump (an irrigating machine)
独轮车 Transcription: dú lún chē Translation: The wheelbarrow
伞 Transcription: sǎn Translation: The umbrella
纺车 Transcription: fǎnɡ chē Translation: The spinning wheel
船尾舵 Transcription: chuán wěi duò Translation: Rudder

The compass is considered to be one of the four great inventions of ancient China.
Before the compass was invented, people depended upon the position of the sun and stars to tell them the direction when at sea, which only worked when it was not cloudy. The invention of the compass solved the problem.

Over 2,000 years ago, in the Warring States Period, Chinese ancestors invented the earliest compass – Si Nan, also known as the South Pointer. Si Nan was composed of two parts: a spoon and a tray. The spoon was cut from an intact piece of natural loadstone, with its handle as the South Pole and its round, smooth bottom as the center of gravity. The tray, on the other hand, was made of bronze, and at the center, there was a round, smooth groove, carved with checks and words indicating the 24 directions. When the spoon was put into the groove, it would rotate flexibly. When the spoon stopped, its handle would point to the south. This instrument was the predecessor of the magnetic compass.

However, since it was easy for natural loadstone (magnetic iron oxide) to lose its magnetism, Si Nan could not be widely used. During the Northern Song Dynasty, artificial magnetization was discovered, giving rise to the Pointing-to-the-South Fish, which was made from a piece of thin iron sheet, cut into the shape of a fish, magnetized in a geomagnetic field, and put into water, floating and lying north-to-south. However, due to its weak magnetic field, Pointing-to-the-South Fish was not of much practical value. On the basis of the Pointing-to-the-South Fish, people replaced the thin iron sheet with a magnetized steel needle, giving rise to the earliest artificially magnetic compass.

The compass was soon employed in navigation. The earliest recorded use of the compass in navigation was in Zhu Yu’s Ping Zhou  Ke Tan (written between 1119~1125), which recorded Zhu  Yu’s experiences in Guangzhou (South China’s Guangdong province), where navigation was highly developed. Zhu  also wrote about some of the experienced sailors, “The sailors know how to pinpoint the ship’s position; they watch the stars at night and the sun in the day, and when it is cloudy, they use the compass.” This might be the earliest record on the use of the compass in the world’s navigational history. Initiated by the Chinese people, this navigational instrument was a grand innovation in navigational technology.

Soon after this, Arabian sea-bound boats also employed the navigation device, and went on to introduce it to the European countries. As Friedrich Engels pointed out in his book Natural Dialectics, “The magnetic needle arrived in Europe via the Arabs in around 1180.” The statement shows the Europeans applied the compass in navigation 80 years after the Chinese.