Su Song (, 1020–1101),
courtesy name
A courtesy name ( zh, s=字, p=zì, l=character), also known as a style name, is an additional name bestowed upon individuals at adulthood, complementing their given name. This tradition is prevalent in the East Asian cultural sphere, particula ...
Zirong (), was a Chinese
polymath
A polymath or polyhistor is an individual whose knowledge spans many different subjects, known to draw on complex bodies of knowledge to solve specific problems. Polymaths often prefer a specific context in which to explain their knowledge, ...
ic scientist and statesman who lived during the
Song dynasty
The Song dynasty ( ) was an Dynasties of China, imperial dynasty of China that ruled from 960 to 1279. The dynasty was founded by Emperor Taizu of Song, who usurped the throne of the Later Zhou dynasty and went on to conquer the rest of the Fiv ...
(960–1279). He exceled in numerous fields including but not limited to
mathematics
Mathematics is a field of study that discovers and organizes methods, Mathematical theory, theories and theorems that are developed and Mathematical proof, proved for the needs of empirical sciences and mathematics itself. There are many ar ...
,
astronomy
Astronomy is a natural science that studies celestial objects and the phenomena that occur in the cosmos. It uses mathematics, physics, and chemistry in order to explain their origin and their overall evolution. Objects of interest includ ...
,
cartography
Cartography (; from , 'papyrus, sheet of paper, map'; and , 'write') is the study and practice of making and using maps. Combining science, aesthetics and technique, cartography builds on the premise that reality (or an imagined reality) can ...
,
geography
Geography (from Ancient Greek ; combining 'Earth' and 'write', literally 'Earth writing') is the study of the lands, features, inhabitants, and phenomena of Earth. Geography is an all-encompassing discipline that seeks an understanding o ...
,
metallurgy
Metallurgy is a domain of materials science and engineering that studies the physical and chemical behavior of metallic elements, their inter-metallic compounds, and their mixtures, which are known as alloys.
Metallurgy encompasses both the ...
,
mechanical engineering
Mechanical engineering is the study of physical machines and mechanism (engineering), mechanisms that may involve force and movement. It is an engineering branch that combines engineering physics and engineering mathematics, mathematics principl ...
,
hydraulic engineering,
poetry
Poetry (from the Greek language, Greek word ''poiesis'', "making") is a form of literature, literary art that uses aesthetics, aesthetic and often rhythmic qualities of language to evoke meaning (linguistics), meanings in addition to, or in ...
, and
statesmanship
A statesman or stateswoman is a politician or a leader in an organization who has had a long and respected career at the national or international level, or in a given field.
Statesman or statesmen may also refer to:
Newspapers United States
...
.
Su Song was the engineer for a
hydro-mechanical astronomical
Astronomy is a natural science that studies celestial objects and the phenomena that occur in the cosmos. It uses mathematics, physics, and chemistry in order to explain their origin and their overall evolution. Objects of interest include ...
clock tower located in
Kaifeng. It employed an early
escapement
An escapement is a mechanical linkage in mechanical watches and clocks that gives impulses to the timekeeping element and periodically releases the gear train to move forward, advancing the clock's hands. The impulse action transfers energy to t ...
mechanism.
[Needham, Volume 4, Part 2, 445.][Needham, Volume 4, Part 2, 448.][Bodde, 140.][Fry, 10.] The escapement mechanism of Su's clock tower was invented by the Tang dynasty
Buddhist
Buddhism, also known as Buddhadharma and Dharmavinaya, is an Indian religion and List of philosophies, philosophical tradition based on Pre-sectarian Buddhism, teachings attributed to the Buddha, a wandering teacher who lived in the 6th or ...
monk
A monk (; from , ''monachos'', "single, solitary" via Latin ) is a man who is a member of a religious order and lives in a monastery. A monk usually lives his life in prayer and contemplation. The concept is ancient and can be seen in many reli ...
Yi Xing
Yixing (, 683–727) was a Buddhist monk of the Tang dynasty, recognized for his accomplishments as an astronomer, a reformer of the calendar system, a specialist in the ''I Ching, Yijing'' (易經), and a distinguished Buddhist figure with exp ...
and government official Liang Lingzan in 725 AD to operate a water-powered
armillary sphere, however Su's armillary sphere was the first to utilize a mechanical clock drive.
[Needham, Volume 3, 351.] Su's clock tower also featured the oldest known endless power-transmitting
chain drive, called the ''tian ti'' (), or "celestial ladder", as depicted in his horological treatise.
[Needham, Volume 4, Part 2, 111.] The clock tower had 133 different
clock jacks to indicate and
sound the hours. The clock was dismantled by the
invading Jurchen army in 1127 AD, and although attempts were made to reassemble it, the tower was never successfully reinstated.
Su Song's treatise about the clock tower, ''Xinyi Xiangfayao'' (), was written in 1092 and received its official printed publication in 1094. The ''Xinyi Xiangfayao'' was Su's best-known treatise, but the polymath compiled other works as well. He completed a large
celestial atlas of several
star maps, several
terrestrial maps, as well as a treatise on pharmacology. The latter discussed related subjects on mineralogy, zoology, botany, and
metallurgy
Metallurgy is a domain of materials science and engineering that studies the physical and chemical behavior of metallic elements, their inter-metallic compounds, and their mixtures, which are known as alloys.
Metallurgy encompasses both the ...
.
Life and works
Career as a scholar-official
Su Song was of
Hokkien
Hokkien ( , ) is a Varieties of Chinese, variety of the Southern Min group of Chinese language, Chinese languages. Native to and originating from the Minnan region in the southeastern part of Fujian in southeastern China, it is also referred ...
ancestry
who was born in modern-day
Fujian
Fujian is a provinces of China, province in East China, southeastern China. Fujian is bordered by Zhejiang to the north, Jiangxi to the west, Guangdong to the south, and the Taiwan Strait to the east. Its capital is Fuzhou and its largest prefe ...
, near medieval
Quanzhou
Quanzhou is a prefecture-level city, prefecture-level port city on the north bank of the Jin River, beside the Taiwan Strait in southern Fujian, China, People's Republic of China. It is Fujian's largest most populous metropolitan region, wi ...
.
Like his contemporary,
Shen Kuo
Shen Kuo (; 1031–1095) or Shen Gua, courtesy name Cunzhong (存中) and Art name#China, pseudonym Mengqi (now usually given as Mengxi) Weng (夢溪翁),Yao (2003), 544. was a Chinese polymath, scientist, and statesman of the Song dynasty (960� ...
(1031–1095), Su Song was a
polymath
A polymath or polyhistor is an individual whose knowledge spans many different subjects, known to draw on complex bodies of knowledge to solve specific problems. Polymaths often prefer a specific context in which to explain their knowledge, ...
, a person whose expertise spans a significant number of different fields of study. It was written by his junior colleague and
Hanlin scholar
Ye Mengde (1077–1148)
[Liu, 593.] that in Su's youth, he mastered the
provincial exams and rose to the top of the examination list for writing the best article on general principles and structure of the
Chinese calendar
The traditional Chinese calendar, dating back to the Han dynasty, is a lunisolar calendar that blends solar, lunar, and other cycles for social and agricultural purposes. While modern China primarily uses the Gregorian calendar for officia ...
.
From an early age, his interests in astronomy and calendrical science led him onto a distinguished path as a
state bureaucrat. In his spare time, he was fond of writing poetry, which he used to praise the works of artists such as the painter
Li Gonglin (1049–1106).
[Edwards, 175–176.][Harrist, 269.] He was also an antiquarian and
collector of old artworks from previous dynasties.
In matters of administrative government, he had attained the rank of Ambassador and President of the
Ministry of Personnel at the capital of Kaifeng, and was known also as an expert in administration and finance.
[Needham, Volume 4, Part 2, 32.] After serving in the
Ministry of Personnel, he became a
Minister of Justice in 1086.
He was appointed as a distinguished editor for the Academy of Scholarly Worthies, where in 1063 he edited, redacted, commented on, and added a preface for the classic work ''
Huainanzi
The ''Huainanzi'' is an ancient Chinese text made up of essays from scholarly debates held at the court of Liu An, Prince of Huainan, before 139 BCE. Compiled as a handbook for an enlightened sovereign and his court, the work attempts to defi ...
'' of the
Han dynasty
The Han dynasty was an Dynasties of China, imperial dynasty of China (202 BC9 AD, 25–220 AD) established by Liu Bang and ruled by the House of Liu. The dynasty was preceded by the short-lived Qin dynasty (221–206 BC ...
(202 BC–220 AD).
[Roth, 224 & 226.] Eventually, Su rose to the post of Vice President of the
Chancellery Secretariat. Among many honorable positions and titles conferred upon him, Su Song was also one of the 'Deputy Tutors of the Heir Apparent'. At court, he chose to distance himself from the political rivalries of the Conservatives, led by Prime Minister
Sima Guang (1019–1086), and the Reformists, led by Prime Minister
Wang Anshi (1021–1086); although many of his associates were of the Conservative faction.
In 1077, he was dispatched on a diplomatic mission to the
Liao dynasty of the
Khitan people
The Khitan people (Khitan small script: ; ) were a historical Eurasian nomads, nomadic people from Northeast Asia who, from the 4th century, inhabited an area corresponding to parts of modern Mongolia, Northeast China and the Russian Far East.
...
to the north,
[Needham, Volume 4, Part 2, 446–447.] sharing ideas about calendrical science, as the Liao state had created its own calendar in 994 AD.
[Bowman, 105.] In a finding that reportedly embarrassed the court, Su Song acknowledged to the emperor that the calendar of the Khitan people was in fact a bit more accurate than their own, resulting in the fining and punishment of officials in the Bureau of Astronomy and Calendar.
[Needham, Volume 4, Part 2, 447.] Su was supposed to travel north to Liao and arrive promptly for a birthday celebration and feast on a day which coincided with the
winter solstice
The winter solstice, or hibernal solstice, occurs when either of Earth's geographical pole, poles reaches its maximum axial tilt, tilt away from the Sun. This happens twice yearly, once in each hemisphere (Northern Hemisphere, Northern and So ...
of the Song calendar, but was actually a day behind the Liao calendar.
[Wittfogel & Feng, 599.] Historian Liu Heping states that
Emperor Zhezong of Song sponsored Su Song's clocktower in 1086 in order to compete with the Liao for "scientific and national superiority."
[Liu, 577.] In 1081, the court instructed Su Song to compile into a book the diplomatic history of Song-Liao relations, an elaborate task that, once complete, filled 200 volumes.
[Breslin, 14.] With his extensive knowledge of
cartography
Cartography (; from , 'papyrus, sheet of paper, map'; and , 'write') is the study and practice of making and using maps. Combining science, aesthetics and technique, cartography builds on the premise that reality (or an imagined reality) can ...
, Su Song was able to settle a heated border dispute between the Song and Liao dynasties.
[Wright, 213.]
Astronomy
Su Song also created a celestial atlas (in five separate maps), which had the hour circles between the xiu (
lunar mansions) forming the
astronomical meridians, with stars marked in an equidistant cylindrical projection on each side of the
equator
The equator is the circle of latitude that divides Earth into the Northern Hemisphere, Northern and Southern Hemisphere, Southern Hemispheres of Earth, hemispheres. It is an imaginary line located at 0 degrees latitude, about in circumferen ...
,
[Miyajima, Kazuhiko (1997). ''Projection Methods in Chinese, Korean and Japanese Star Maps'' from "Highlights of Astronomy" vol. 11B p. 714. Ed. J. Andersen. Norwell: Kluwer Academic Publishers.] and thus, was in accordance to their north polar distances.
[Needham, Volume 4, Part 3, 569.] Furthermore, Su Song must have taken advantage of the astronomical findings of his political rival and
contemporary astronomer Shen Kuo.
[Needham, Volume 3, 278.] Su Song's fourth star map places the position of the
pole star halfway between Tian shu (−350 degrees) and the current
Polaris
Polaris is a star in the northern circumpolar constellation of Ursa Minor. It is designated α Ursae Minoris (Latinisation of names, Latinized to ''Alpha Ursae Minoris'') and is commonly called the North Star or Pole Star. With an ...
; this was the more accurate calculation (by 3 degrees) that Shen Kuo had made when he observed the pole star over a period of three months with his width-improved sighting tube.
There were many star maps written before Song's book, but the star maps published by Su represent the oldest extant star maps in
printed form.
[Sivin, III, 32.]
Pharmacology, botany, zoology, and mineralogy
In 1070, Su Song and a team of scholars compiled and edited the ''Bencao Tujing'' ('Illustrated Pharmacopoeia', original source material from 1058 to 1061), which was a groundbreaking treatise on pharmaceutical
botany
Botany, also called plant science, is the branch of natural science and biology studying plants, especially Plant anatomy, their anatomy, Plant taxonomy, taxonomy, and Plant ecology, ecology. A botanist or plant scientist is a scientist who s ...
,
zoology
Zoology ( , ) is the scientific study of animals. Its studies include the anatomy, structure, embryology, Biological classification, classification, Ethology, habits, and distribution of all animals, both living and extinction, extinct, and ...
, and
mineralogy
Mineralogy is a subject of geology specializing in the scientific study of the chemistry, crystal structure, and physical (including optical mineralogy, optical) properties of minerals and mineralized artifact (archaeology), artifacts. Specific s ...
.
[Wu, 5.] In compiling information for pharmaceutical knowledge, Su Song worked with such notable scholars as Zhang Yuxi, Lin Yi, Zhang Dong, and many others.
[Unschuld, 60.]
This treatise documented a wide range of pharmaceutical practices, including the use of
ephedrine
Ephedrine is a central nervous system (CNS) stimulant and sympathomimetic agent that is often used to prevent hypotension, low blood pressure during anesthesia. It has also been used for asthma, narcolepsy, and obesity but is not the preferred ...
as a drug.
[Needham, Volume 4, Part 2, 446.] It includes valuable information on metallurgy and the steel and iron industries during 11th century China. He created a systematic approach to listing various different minerals and their use in medicinal concoctions, such as all the variously known forms of
mica
Micas ( ) are a group of silicate minerals whose outstanding physical characteristic is that individual mica crystals can easily be split into fragile elastic plates. This characteristic is described as ''perfect basal cleavage''. Mica is co ...
that could be used to cure ills through
digestion
Digestion is the breakdown of large insoluble food compounds into small water-soluble components so that they can be absorbed into the blood plasma. In certain organisms, these smaller substances are absorbed through the small intestine into th ...
.
[Needham, Volume 3, 648.] He wrote of the
subconchoidal fracture of native
cinnabar
Cinnabar (; ), or cinnabarite (), also known as ''mercurblende'' is the bright scarlet to brick-red form of Mercury sulfide, mercury(II) sulfide (HgS). It is the most common source ore for refining mercury (element), elemental mercury and is t ...
, signs of
ore beds, and provided description on crystal form.
[Needham, Volume 3, 649.] Similar to the ore channels formed by circulation of ground water written of by the later German scientist
Georgius Agricola
Georgius Agricola (; born Georg Bauer; 24 March 1494 – 21 November 1555) was a German Humanist scholar, mineralogist and metallurgist. Born in the small town of Glauchau, in the Electorate of Saxony of the Holy Roman Empire, he was b ...
, Su Song made similar statements concerning
copper carbonate, as did the earlier ''Rihua Bencao'' of 970 with
copper sulphate.
Su's book was also the first pharmaceutical treatise written in China to describe the
flax
Flax, also known as common flax or linseed, is a flowering plant, ''Linum usitatissimum'', in the family Linaceae. It is cultivated as a food and fiber crop in regions of the world with temperate climates. In 2022, France produced 75% of t ...
, ''
Urtica thunbergiana'', and ''Corchoropsis tomentosa'' (crenata) plants.
[Needham, Volume 6, Part 1, 174, 175.] According to Edward H. Schafer, Su accurately described the translucent quality of fine
realgar, its origin from pods found in rocky river gorges, its matrix being pitted with holes and having a deep red, almost purple color, and that the mineral varied in sizes ranging from the size of a pea to a walnut.
[Schafer, 81.]
Citing evidence from an ancient work by
Zheng Xuan (127–200), Su believed that physicians of the ancient
Zhou dynasty
The Zhou dynasty ( ) was a royal dynasty of China that existed for 789 years from until 256 BC, the longest span of any dynasty in Chinese history. During the Western Zhou period (771 BC), the royal house, surnamed Ji, had military ...
(1046–256 BC) used realgar as a remedy for
ulcer
An ulcer is a discontinuity or break in a bodily membrane that impedes normal function of the affected organ. According to Robbins's pathology, "ulcer is the breach of the continuity of skin, epithelium or mucous membrane caused by sloughin ...
s.
[Schafer, 83.] As believed in Su's day, the "five poisons" used by Zhou era physicians for this purpose were thought to be cinnabar, realgar,
chalcanthite
Chalcanthite (, ) is a richly colored blue-green water-soluble sulfate mineral . It is commonly found in the late-stage oxidation zones of copper deposits. Due to its ready solubility, chalcanthite is more common in arid regions.
Chalcanthite i ...
,
alum
An alum () is a type of chemical compound, usually a hydrated double salt, double sulfate salt (chemistry), salt of aluminium with the general chemical formula, formula , such that is a valence (chemistry), monovalent cation such as potassium ...
, and
magnetite
Magnetite is a mineral and one of the main iron ores, with the chemical formula . It is one of the iron oxide, oxides of iron, and is ferrimagnetism, ferrimagnetic; it is attracted to a magnet and can be magnetization, magnetized to become a ...
.
Su made systematic descriptions of animals and the environmental regions they could be found, such as different species of freshwater, marine, and shore crabs.
[West, 606.] For example, he noted that the freshwater crab species ''Eriocher sinensis'' could be found in the
Huai River
The Huai River, formerly romanized as the Hwai, is a major river in East China, about long with a drainage area of . It is located about midway between the Yellow River and Yangtze River, the two longest rivers and largest drainage basins ...
running through
Anhui
Anhui is an inland Provinces of China, province located in East China. Its provincial capital and largest city is Hefei. The province is located across the basins of the Yangtze and Huai rivers, bordering Jiangsu and Zhejiang to the east, Jiang ...
, in waterways near the capital city, as well as reservoirs and marshes of
Hebei
Hebei is a Provinces of China, province in North China. It is China's List of Chinese administrative divisions by population, sixth-most populous province, with a population of over 75 million people. Shijiazhuang is the capital city. It bor ...
.
Su's book was preserved and copied into the ''
Bencao Gangmu'' of the
Ming dynasty
The Ming dynasty, officially the Great Ming, was an Dynasties of China, imperial dynasty of China that ruled from 1368 to 1644, following the collapse of the Mongol Empire, Mongol-led Yuan dynasty. The Ming was the last imperial dynasty of ...
(1368–1644) physician and pharmacologist
Li Shizhen (1518–1593).
[West, 605.]
Horology and mechanical engineering
Su Song compiled one of the greatest Chinese
horological treatises of the
Middle Ages
In the history of Europe, the Middle Ages or medieval period lasted approximately from the 5th to the late 15th centuries, similarly to the post-classical period of global history. It began with the fall of the Western Roman Empire and ...
, surrounding himself with an entourage of notable engineers and astronomers to assist in various projects. ''Xinyi Xiangfayao'' (lit. "Essentials of a New Method for Mechanizing the Rotation of an Armillary Sphere and a Celestial Globe"), written in 1092, was the final product of his life's achievements in horology and clockwork. The book included 47 different illustrations of great detail of the mechanical workings for his
astronomical
Astronomy is a natural science that studies celestial objects and the phenomena that occur in the cosmos. It uses mathematics, physics, and chemistry in order to explain their origin and their overall evolution. Objects of interest include ...
clock tower.
[Ceccarelli, 58.]
Su Song's greatest project was the 40-foot-tall water-powered astronomical clock tower constructed in Kaifeng, the wooden pilot model completed in 1088, the bronze components cast by 1090, while the wholly finished work was completed by 1094 during the reign of
Emperor Zhezong of Song.
[Fry, 9.][Needham, Volume 4, Part 2, 495.] The emperor had previously commissioned
Han Gonglian, Acting Secretary of the Ministry of Personnel, to head the project, but the leadership position was instead handed down to Su Song. The emperor ordered in 1086 for Su to reconstruct the ''hun yi'', or "armillary clock", for a new clock tower in the capital city. Su worked with the aid of Han Gong-lian, who applied his extensive knowledge of mathematics to the construction of the clock tower.
[Needham, Volume 4, Part 2, 39.] A small-scale wooden model was first crafted by Su Song, testing its intricate parts before applying it to an actual full-scale clock tower.
[Needham, Volume 4, Part 2, 465.] In the end, the clock tower had many impressive features, such as the hydro-mechanical, rotating armillary sphere crowning the top level and weighing some 10 to 20 tons,
a bronze celestial globe located in the middle that was 4.5 feet in diameter,
mechanically timed and rotating
mannequin
A mannequin (sometimes spelled as manikin and also called a dummy, lay figure, or dress form) is a doll, often articulated, used by artists, tailors, dressmakers, window dressers and others, especially to display or fit clothing and show off dif ...
s dressed in miniature
Chinese clothes that exited miniature opening doors to announce the time of day by presenting designated reading plaques, ringing bells and gongs, or beating drums,
[Needham, Volume 4, Part 2, 455.] a sophisticated use of oblique gears and an escapement mechanism,
[Needham, Volume 4, Part 2, 456.] as well as an exterior facade of a fanciful
Chinese pagoda
A pagoda is a tiered tower with multiple eaves common to Thailand, Cambodia, Nepal, India, China, Japan, Korea, Myanmar, Vietnam, and other parts of Asia. Most pagodas were built to have a religious function, most often Buddhism, Buddhist, bu ...
. Upon its completion, the tower was called the ''Shui Yun Yi Xiang Tai'', or "Tower for the Water-Powered Sphere and Globe". Joseph Needham writes:
Years after Su's death, the capital city of Kaifeng was
besieged and captured in 1127 by the
Jurchens of the
Manchuria
Manchuria is a historical region in northeast Asia encompassing the entirety of present-day northeast China and parts of the modern-day Russian Far East south of the Uda (Khabarovsk Krai), Uda River and the Tukuringra-Dzhagdy Ranges. The exact ...
-based
Jin dynasty during the
Jin–Song wars.
[Wright, 96.] The clock tower was dismantled piece by piece by the Jurchens, who carted its components back to their own capital in modern-day Beijing. However, due to the complexity of the tower, they were unable to piece it back together. The new
Emperor Gaozong of Song instructed Su's son, Su Xie, to construct a new astronomical clock tower in its place, and Su Xie set to work studying his father's texts with a team of other experts. However, they were also unsuccessful in creating another clock tower, and Su Xie was convinced that Su Song had purposefully left out essential components in his written work and diagrams so that others would not steal his ideas.
As the
sinologist historian
Derk Bodde points out, Su Song's astronomical clock did not lead to a new generation of mass-produced clockworks throughout China since his work was largely a government-sponsored endeavor for the use of astronomers and
astrologer
Astrology is a range of Divination, divinatory practices, recognized as pseudoscientific since the 18th century, that propose that information about human affairs and terrestrial events may be discerned by studying the apparent positions ...
s in the imperial court.
[Bodde, 362.] Yet the mechanical legacy of Su Song did not end with his work. In about 1150, the writer Xue Jixuan noted that there were four types of clocks in his day, the basic
waterclock, the
incense clock, the
sundial
A sundial is a horology, horological device that tells the time of day (referred to as civil time in modern usage) when direct sunlight shines by the position of the Sun, apparent position of the Sun in the sky. In the narrowest sense of the ...
, and the clock with 'revolving and snapping springs' ('gun tan').
[Needham, Volume 4, Part 2, 462.] The rulers of the continuing
Yuan dynasty
The Yuan dynasty ( ; zh, c=元朝, p=Yuáncháo), officially the Great Yuan (; Mongolian language, Mongolian: , , literally 'Great Yuan State'), was a Mongol-led imperial dynasty of China and a successor state to the Mongol Empire after Div ...
(1279–1368 AD) had a vested interest in the advancement of mechanical clockworks.
[Fry, 12.] The astronomer
Guo Shoujing helped restore the
Beijing Ancient Observatory beginning in 1276, where he crafted a water-powered armillary sphere and clock with clock jacks being fully implemented and sounding the hours.
[Needham, Volume 4, Part 2, 504–505.] Complex gearing for uniquely Chinese clockworks were continued in the
Ming dynasty
The Ming dynasty, officially the Great Ming, was an Dynasties of China, imperial dynasty of China that ruled from 1368 to 1644, following the collapse of the Mongol Empire, Mongol-led Yuan dynasty. The Ming was the last imperial dynasty of ...
(1368–1644), with new designs driven by the power of falling sand instead of water to provide motive power to the wheel drive, and some Ming clocks perhaps featured reduction gearing rather than the earlier escapement of Su Song.
[Needham, Volume 4, Part 2, 509–512.] The earliest such design of a sand-clock was made by
Zhan Xiyuan around 1370, which featured not only the scoop wheel of Su Song' device, but also a new addition of a
stationary dial face over which a pointer circulated, much like new European clocks of the same period.
[Needham, Volume 4, Part 2, 511.]
Su Song's escapement mechanism
In Su Song's waterwheel linkwork device, the action of the escapement's arrest and release was achieved by gravity exerted periodically as the continuous flow of liquid filled containers of a limited size.
In a single line of evolution, Su Song's clock therefore united the concept of the clepsydra and the mechanical clock into one device run by mechanics and hydraulics. In his memorial, Su Song wrote about this concept:
In his writing, Su Song credited, as the predecessor of his working clock, the hydraulic-powered armillary sphere of
Zhang Heng
Zhang Heng (; AD 78–139), formerly romanization of Chinese, romanized Chang Heng, was a Chinese polymathic scientist and statesman who lived during the Han dynasty#Eastern Han (25–220 AD), Eastern Han dynasty. Educated in the capital citi ...
(78–139 AD), an earlier Chinese scientist.
[Needham, Volume 4, Part 2, 466.] Su Song was also strongly influenced by the earlier armillary sphere created by
Zhang Sixun (976 AD), who also employed the escapement mechanism and used liquid
mercury instead of water in the waterwheel of his astronomical clock tower (since liquid mercury would not freeze during winter and would not corrode and rust metal components over time).
[Needham, Volume 4, Part 2, 469–471.] However, Su Song stated in his writing that after Zhang's death, no one was able to replicate his device, much like his own.
[Needham Volume 4, Part 2, 470.]
The mechanical clockworks for Su Song's astronomical tower featured a great driving-wheel that was 11 feet in diameter, carrying 36 scoops, into each of which water poured at a uniform rate from the "constant-level tank" (Needham, Fig. 653). The main driving shaft of iron, with its cylindrical necks supported on iron crescent-shaped bearings, ended in a pinion, which engaged a gear wheel at the lower end of the main vertical transmission shaft.
[Needham, Volume 4, Part 2, 451.]
Joseph Needham gives a general description of the clock tower itself:
That was figure Fig. 650, while Fig. 656 displays the upper and lower
norias with their tanks and the manual wheel for operating them.
Fig. 657 displays a rather miniature and scaled-down picture for the basics of the escapement mechanism in an illustration (from Su's book), with Needham's caption here in this quote: "The 'celestial balance' or escapement mechanism of Su Song's clockwork (Xinyi Xiangfayao, ch. 3, p. 18b)".
[Needham, Volume 4, Part 2, 458.] The latter figure carefully labels:
*a right upper lock
*upper link
*left upper lock
*axle or pivot
*long chain
*upper counterweight
*sump
*checking fork of the lower balancing lever
*coupling tongue
*main (i.e., lower) counterweight
Figure 658 displays a more intricate and most-telling half-page scale drawing of Su Song's large escapement mechanism, labeling these individual parts as they interact with one another:
*arrested spoke
*left upper lock
*scoop being filled by
*water jet from constant-level tank
*small counterweight
*checking fork tripped by a projection pin on the scoop, and forming the near end of
*the lower balancing lever with
*its lower counterweight
*coupling tongue, connected by
*the long chain with
*the upper balancing lever, which has at its far end
*the upper counterweight, and at its near end
*a short length chain connecting it with the upper lock beneath it;
*right upper lock
[Needham, Volume 4, Part 2, 460.]
The endless chain drive
The world's oldest illustrated depiction of an endless power-transmitting chain drive is from Su Song's horological treatise.
It was used in the clockworks for coupling the main drive shaft to the armillary sphere gearbox (rotating three small pinions),
[Needham, Volume 4, Part 2, 457.] as seen in Needham's Fig. 410 and Fig. 652.
This belonged to the uppermost end of the main vertical transmission shaft, incorporating right angle gears and oblique gears connected by a short idling shaft.
The toothed ring gear called the diurnal motion gear ring was fit around the shell of the armillary sphere along the declination parallel near the southern pole.
[Needham, Volume 4, Part 2, 456–457.] Although the ancient
Greek Philo of Byzantium
Philo of Byzantium (, ''Phílōn ho Byzántios'', ), also known as Philo Mechanicus (Latin for "Philo the Engineer"), was a Greek engineer, physicist and writer on mechanics, who lived during the latter half of the 3rd century BC. Although he wa ...
(3rd century BC) featured a sort of endless belt for his magazine
arcuballista, which did not transmit continuous power,
the influential source for Su Song's chain drive is most likely the continuously driven
chain pump known in China since the
Han dynasty
The Han dynasty was an Dynasties of China, imperial dynasty of China (202 BC9 AD, 25–220 AD) established by Liu Bang and ruled by the House of Liu. The dynasty was preceded by the short-lived Qin dynasty (221–206 BC ...
(202 BC–220 AD).
From his horological treatise, Su Song states:
In addition, the motion gear rings and the upper drive wheel both had 600 teeth, which by Su's mathematical precision carefully calculated measured units of the day in a division of 1/600.
[Fry, 11.] These gears, having 600 teeth, thus ensured the division of the day into measurements of 2 minutes and 24 seconds each.
Su Song's armillary sphere
In Joseph Needham's third volume of ''Science and Civilization in China'', the drawing for Fig. 159 displays a drawing of Su Song's armillary sphere (as depicted in his 11th century treatise), complete with three 'nests' or layers of mechanically rotated rings. It was the earlier Chinese astronomer Li Chun-feng of the Tang dynasty who in 633 AD created the first armillary sphere with three layers to calibrate multiple aspects of astronomical observation.
[Needham, Volume 3, 343.] Zhang's armillary sphere has often been compared to that of the 13th century monarch
Alfonso X of Castile
Alfonso X (also known as the Wise, ; 23 November 1221 – 4 April 1284) was King of Castile, Kingdom of León, León and Kingdom of Galicia, Galicia from 1 June 1252 until his death in 1284. During the April 1257 Imperial election, election of 1 ...
in Islamic-era Spain. The chief difference was that Alfonso's instrument featured an arrangement for making measurements of the
azimuth
An azimuth (; from ) is the horizontal angle from a cardinal direction, most commonly north, in a local or observer-centric spherical coordinate system.
Mathematically, the relative position vector from an observer ( origin) to a point ...
and altitude, which was present in the
Arabic
Arabic (, , or , ) is a Central Semitic languages, Central Semitic language of the Afroasiatic languages, Afroasiatic language family spoken primarily in the Arab world. The International Organization for Standardization (ISO) assigns lang ...
tradition, while Su Song's armillary sphere was duly graduated.
[Needham, Volume 3, 353.] For the drawing of Su's armillary sphere, the listing of components are:
*The Outer Nest
[Needham, Volume 3, 351.]
**meridian circle
**horizon circle
**outer equator circle
*The Middle Nest
**solstitial colure circle
**ecliptic circle
**diurnal motion gear-ring, connecting with the power-drive
*The Inner Nest
**polar-mounted declination ring or hour-angle circle, with
**sighting tube attached to it and strengthened by a
**diametral brace
*Other Parts
**vertical column concealing the transmission shaft
**supporting columns in the form of dragons
**cross-piece of the base, incorporating water-levels
**south polar pivot
**north polar pivot
Transmission of Su's text and his legacy
When Su Song's ''Xinyi Xiangfayao'' was written in 1092 and the horological monograph finalized and presented in 1094, his work was published and widely
printed
Printing is a process for mass reproducing text and Printmaking, images using a master form or template. The earliest non-paper products involving printing include cylinder seals and objects such as the Cyrus Cylinder and the Cylinders of Nabon ...
in the north (see
woodblock printing and
movable type
Movable type (US English; moveable type in British English) is the system and technology of printing and typography that uses movable Sort (typesetting), components to reproduce the elements of a document (usually individual alphanumeric charac ...
of
Bi Sheng). In the south, printing and circulation of his work was not widely distributed until Shi Yuanzhi of
Jiangsu
Jiangsu is a coastal Provinces of the People's Republic of China, province in East China. It is one of the leading provinces in finance, education, technology, and tourism, with its capital in Nanjing. Jiangsu is the List of Chinese administra ...
had it printed there in 1172.
When presenting his clocktower design to the Emperor Zhezong, Su Song equated the constant flow of water with the continuous movements of the heavens, the latter of which symbolized the unceasing power of the emperor.
[Liu, 578, 585.] This appealed to the emperor, who featured artwork representing the clocktower on vehicles of major imperial processions, as illustrated in the ''Illustration of the Imperial Grand Carriage Procession'' of 1053.
[Liu, 578.]
The later
Ming dynasty
The Ming dynasty, officially the Great Ming, was an Dynasties of China, imperial dynasty of China that ruled from 1368 to 1644, following the collapse of the Mongol Empire, Mongol-led Yuan dynasty. The Ming was the last imperial dynasty of ...
/
Qing dynasty
The Qing dynasty ( ), officially the Great Qing, was a Manchu-led Dynasties of China, imperial dynasty of China and an early modern empire in East Asia. The last imperial dynasty in Chinese history, the Qing dynasty was preceded by the ...
scholar Qian Zeng (1629–1699) held an old volume of Su's work, which he faithfully reproduced in a newly printed edition. He took special care in avoiding any rewording or inconsistencies with the original text as well.
Again, it was later reprinted by Zhang Xizu (1799–1844).
Su Song's treatise on astronomical clockwork was not the only one made in China during his day, as the ''
Song Shi'' (compiled in 1345) records the written treatise of the ''Shuiyunhun Tianjiyao'' (Wade–Giles: ''Shui Yun Hun Thien Chi Yao''; lit. Essentials of the
echnique ofmaking Astronomical Apparatus revolve by Water-Power), written by Juan Taifa. However, this treatise no longer survives.
[Needham, Volume 4, Part 2, 450.]
European
Jesuit
The Society of Jesus (; abbreviation: S.J. or SJ), also known as the Jesuit Order or the Jesuits ( ; ), is a religious order (Catholic), religious order of clerics regular of pontifical right for men in the Catholic Church headquartered in Rom ...
visitors to China like
Matteo Ricci and
Nicolas Trigault briefly wrote about Chinese clocks with wheel-driven mechanisms,
[Needham, Volume 4, Part 2, 438.] but others mistakenly believed that the Chinese had never advanced beyond the stage of the
clepsydra,
incense clock, and
sundial
A sundial is a horology, horological device that tells the time of day (referred to as civil time in modern usage) when direct sunlight shines by the position of the Sun, apparent position of the Sun in the sky. In the narrowest sense of the ...
.
They thought that advanced mechanical clockworks were new to China and viewed them as innovations that Europeans could introduce.
[Needham, Volume 4, Part 2, 435–440.] Although not as prominent as in the Song period, contemporary Chinese texts of the
Ming dynasty
The Ming dynasty, officially the Great Ming, was an Dynasties of China, imperial dynasty of China that ruled from 1368 to 1644, following the collapse of the Mongol Empire, Mongol-led Yuan dynasty. The Ming was the last imperial dynasty of ...
(1368–1644) described a relatively unbroken history of mechanical clocks in China, from the 13th to the 16th century.
However, Su Song's clock tower was not independent of external forces to power its movement, as it relied on a
waterwheel via a chain drive mechanism. It was thus not fully mechanical like late medieval European clocks, which typically used descending weights to drive their gears and escapement, requiring periodic winding but functioning without continuous external forces.
In the realm of modern research, the British biochemist and historian of Chinese science
Joseph Needham (1900–1995) (known as Li Yuese in China) conducted extensive research and analysis of Su Song's texts and various achievements in his ''Science and Civilization in China'' book series. Joseph Needham also related many detailed passages from Su's contemporary medieval Chinese sources on the life of Su and his achievements known in his day. In 1956, John Christiansen reconstructed a model of Su Song's clocktower in a famous drawing, which garnered attention in the West towards 11th-century Chinese engineering.
[Liu, 577–579.] A miniature model of Su Song's clock was reconstructed by John Cambridge and is now on display at the
National Science Museum at
South Kensington, London.
In China, the clocktower was reconstructed to one-fifth its actual scale by Wang Zhenduo, who worked for the Chinese Historical Museum in Beijing in the 1950s.
[Xi, 466.]
See also
*
Cartographers
*
Chinese inventions and
discoveries
*
Chinese writers
*
Clock tower
*
Mineralogists
*
Technology of the Song dynasty
*
Water clock
*
Zhang Heng
Zhang Heng (; AD 78–139), formerly romanization of Chinese, romanized Chang Heng, was a Chinese polymathic scientist and statesman who lived during the Han dynasty#Eastern Han (25–220 AD), Eastern Han dynasty. Educated in the capital citi ...
, second-century inventor of water-powered armillary sphere
References
Citations
Sources
* Bodde, Derk (1991). ''Chinese Thought, Society, and Science''. Honolulu: University of Hawaii Press.
* Bowman, John S. (2000). ''Columbia Chronologies of Asian History and Culture''. New York: Columbia University Press.
* Breslin, Thomas A. (2001). ''Beyond Pain: The Role of Pleasure and Culture in the Making of Foreign Affairs''. Westport: Praeger Publishers.
* Ceccarelli, Marco (2004). ''International Symposium on History of Machines and Mechanisms''. New York: Kluwer Academic Publishers.
* Edwards, Richard. "Li Gonglin's Copy of Wei Yan's 'Pasturing Horses'," ''Artibus Asiae'' (Volume 53, Number 1/2, 1993): 168–181; 184–194.
* Fry, Tony (2001). ''The Architectural Theory Review: Archineering in Chinatime''. Sydney: University of Sydney.
* Harrist, Robert E., Jr. "The Artist as Antiquarian: Li Gonglin and His Study of Early Chinese Art," Artibus Asiae (Volume 55, Number 3/4, 1995): 237–280.
* Liu, Heping. ""The Water Mill" and Northern Song Imperial Patronage of Art, Commerce, and Science," ''The Art Bulletin'' (Volume 84, Number 4, 2002): 566–595.
*
Needham, Joseph, Wang Ling & Lu Gwei-Djen (1986)
965 ''
Science and Civilization in China'', Taipei: Caves Books, Ltd. (reprint edition of Cambridge & New York: Cambridge University Press).
** ''Volume 3: Mathematics and the Sciences of the Heavens and the Earth''.
** ''Volume 4: Physics and Physical Technology, Part 2: Mechanical Engineering''
** ''Volume 4: Physics and Physical Technology, Part 3: Civil Engineering and Nautics''
** ''Volume 6: Biology and Biological Technology, Part 1, Botany''
* Roth, Harold D. "Text and Edition in Early Chinese Philosophical Literature," ''Journal of the American Oriental Society'' (Volume 113, Number 2, 1993): 214–227.
* Schafer, Edward H. "Orpiment and Realgar in Chinese Technology and Tradition," ''Journal of the American Oriental Society'' (Volume 75, Number 2, 1955): 73–89.
* Sivin, Nathan (1995). ''Science in Ancient China: Researches and Reflections''. Brookfield, Vermont: VARIORUM, Ashgate Publishing.
* Unschuld, Paul U. (2003). ''Nature, Knowledge, Imagery in an Ancient Chinese Medical Text''. Berkeley: University of California Press.
* West, Stephen H. "Cilia, Scale and Bristle: The Consumption of Fish and Shellfish in The Eastern Capital of The Northern Song," ''Harvard Journal of Asiatic Studies'' (Volume 47, Number 2, 1987): 595–634.
* Wittfogel, Karl A. and Feng Chia-Sheng. "History of Chinese Society Liao (907–1125)," Transactions of the American Philosophical Society (Volume 36, 1946): i–xv; 1–752.
* Wright, David Curtis (2001) ''The History of China''. Westport: Greenwood Press.
* Wu, Jing-nuan (2005). ''An Illustrated Chinese Materia Medica''. New York: Oxford University Press.
* Xi, Zezong. "Chinese Studies in the History of Astronomy, 1949–1979," ''Isis'' (Volume 72, Number 3, 1981): 456–470.
External links
Su Song's Clock 1088Su Song in the Encyclopædia Britannica
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