Du Shi
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Du Shi (Wade-Giles: Tu Shih, active 1st century AD) was a Chinese governmental Prefect of Nanyang in 31 AD and a mechanical engineer of the Eastern Han Dynasty in ancient China. Du Shi is credited with being the first to apply hydraulic power (ie. a waterwheel) to operate bellows (air-blowing device) in metallurgy. His invention was used to operate piston-bellows of the blast furnace in order to forge cast iron (a metal product that had been used in China since the 6th century BC, slowly phasing out the dominance of bronze production by the 3rd century BC).
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[edit] The Water-Powered Blast Furnace
Du Shi is mentioned briefly in the Book of Later Han (Hou Han Shu) as follows (in Wade-Giles spelling):
In the seventh year of the Chien-Wu reign period (+31 (AD)) Tu Shih was posted to be Prefect of Nanyang. He was a generous man and his policies were peaceful; he destroyed evil-doers and established the dignity (of his office). Good at planning, he loved the common people and wished to save their labor. He invented a water-power reciprocator (shui phai) for the casting of (iron) agricultural implements. Those who smelted and cast already had the push-bellows to blow up their charcoal fires, and now they were instructed to use the rushing of the water (chi shui) to operate it...Thus the people got great benefit for little labor. They found the 'water(-powered) bellows' convenient and adopted it widely [1].
The historical text Sanguo Zhi (Records of the Three Kingdoms) records the use of both human labor and horse-power to operate metallurgic bellows of a blast furnace before water-power was applied.[1] It also records that around 238 AD, engineer Han Ji (Prefect of Luo-ling) reinvented a similar water-powered bellows that Du Shi had earlier pioneered. Two decades after this, it is recorded that another design for water-powered bellows was created by Du Yu.[1] In the 5th century text of the Wu Chang Ji, its author Pi Ling wrote that a planned, artificial lake had been constructed in the Yuan-Jia reign period (424–429) for the sole purpose of powering water wheels aiding the smelting and casting processes of the Chinese iron industry.[2] The 5th century text Shui Jing Zhu mentions the use of rushing river water to power waterwheels, as does the Tang Dynasty geography text of the Yuan-he Jun Xian Tu Chi, written in 814 AD.[3]
Although Du Shi is the first historical figure to apply water power to metallurgic bellows, the oldest extant Chinese illustration depicting such a device in operation can be seen in a picture of the Nong Shu, printed by 1313 AD during the Yuan Dynasty of China.[4] The text was written by Wang Zhen, who explained the methods used for a water-powered blast-furnace (Wade-Giles spelling):
According to modern study (+1313!), leather bag bellows (wei nang) were used in olden times, but now they always use wooden fan (bellows)(mu shan). The design is as follows. A place beside a rushing torrent is selected, and a vertical shaft (li chu) is set up in a framework with two horizontal wheels (wo lun) so that the lower one is rotated by the force of the water (yung shui chi chuan). The upper one is connected by a driving-belt (hsien so) to a (smaller) wheel (hsuan ku) in front of it, which bears an eccentric lug (lit. oscillating rod, tiao chih). Then all as one, following the turning (of the driving wheel), the connecting-rod (hsing kuang) attached to the eccentric lug pushes and pulls the rocking roller (wo chu), the levers (phan erh) to left and right of which assure the transmission of the motion to the piston-rod (chih mu). Thus this is pushed back and forth, operating the furnace bellows far more quickly than would be possible with man-power.[5]
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- Needham, Joseph (1986). Science and Civilization in China: Volume 4, Part 2. Taipei: Caves Books, Ltd.
