Ma Jun (mechanical engineer)

His most notable invention was that of the south-pointing chariot, a directional compass vehicle which actually had no magnetic function, but was operated by use of differential gears (which applies equal amount of torque to driving wheels rotating at different speeds).

[2] It is because of this revolutionary device (and other achievements) that Ma Jun is known as one of the most brilliant mechanical engineers and inventors of his day (alongside Zhang Heng of the earlier Eastern Han dynasty).

According to his friend and contemporary poet and philosopher Fu Xuan (217–278), Ma Jun was born in Fufeng Commandery (扶風郡), which is located around present-day Xingping, Shaanxi.

[3] Despite this degree, Ma Jun was relatively poor in his youth, yet found means to gain recognition by employing his natural genius in creating mechanical contraptions and inventions.

Gaotang Long and Qin Lang mocked Ma Jun for his belief in historical texts that the south-pointing chariot had actually been invented in the past (as the legend goes, by the Yellow Emperor), something they viewed as nonsensical, non-historical myth.

Ma Jun also made a mountain with wooden images dancing on balls, throwing swords about, hanging upside down on rope ladders, and generally behaving in an assured and easy manner.

The Eastern Han dynasty court eunuch Zhang Rang once ordered the engineer Bi Lan to construct a series of chain pumps outside the capital city of Luoyang, used for irrigation and means of fresh water source.

Ma Jun constructed his square-pallet chain pumps to water newly designated garden space established within Luoyang by Cao Rui.