Science and technology of the Han Dynasty

Han Dynasty

The Han Dynasty was the second imperial dynasty of China, preceded by the Qin Dynasty and succeeded by the Three Kingdoms . It was founded by the rebel leader Liu Bang, known posthumously as Emperor Gaozu of Han. It was briefly interrupted by the Xin Dynasty of the former regent Wang Mang...

(206 BCE – 220 CE) of ancient China

History of China

Chinese civilization originated in various regional centers along both the Yellow River and the Yangtze River valleys in the Neolithic era, but the Yellow River is said to be the Cradle of Chinese Civilization. With thousands of years of continuous history, China is one of the world's oldest...

, divided between the eras of Western Han (206 BCE – 9 CE, when the capital was at Chang'an

Chang'an

Chang'an is an ancient capital of more than ten dynasties in Chinese history, today known as Xi'an. Chang'an literally means "Perpetual Peace" in Classical Chinese. During the short-lived Xin Dynasty, the city was renamed "Constant Peace" ; yet after its fall in AD 23, the old name was restored...

), Xin Dynasty

Xin Dynasty

The Xin Dynasty was a Chinese dynasty which lasted from AD 9 to 23. It followed the Western Han Dynasty and preceded the Eastern Han Dynasty....

of Wang Mang

Wang Mang

Wang Mang , courtesy name Jujun , was a Han Dynasty official who seized the throne from the Liu family and founded the Xin Dynasty , ruling AD 9–23. The Han dynasty was restored after his overthrow and his rule marks the separation between the Western Han Dynasty and Eastern Han Dynasty...

(r. 9–23 CE), and Eastern Han (25–220 CE, when the capital was

History of the Han Dynasty

The Han Dynasty , founded by the peasant rebel leader Liu Bang ,From the Shang to the Sui dynasties, Chinese rulers were referred to in later records by their posthumous names, while emperors of the Tang to Yuan dynasties were referred to by their temple names, and emperors of the Ming and Qing...

at Luoyang

Luoyang

Luoyang is a prefecture-level city in western Henan province of Central China. It borders the provincial capital of Zhengzhou to the east, Pingdingshan to the southeast, Nanyang to the south, Sanmenxia to the west, Jiyuan to the north, and Jiaozuo to the northeast.Situated on the central plain of...

, and after 196 CE at Xuchang

Xuchang

Xuchang is a prefecture-level city in central Henan province in Central China. It borders the provincial capital of Zhengzhou to the northwest, Kaifeng to the northeast, Zhoukou to the east, Luohe to the southeast, and Pingdingshan to the southwest....

), witnessed some of the most significant advancements in premodern Chinese science and technology

History of science and technology in China

The history of science and technology in China is both long and rich with many contributions to science and technology. In antiquity, independently of other civilizations, ancient Chinese philosophers made significant advances in science, technology, mathematics, and astronomy...

.

There were great innovations in metallurgy

Metallurgy

Metallurgy is a domain of materials science that studies the physical and chemical behavior of metallic elements, their intermetallic compounds, and their mixtures, which are called alloys. It is also the technology of metals: the way in which science is applied to their practical use...

. In addition to Zhou-dynasty China's

Zhou Dynasty

The Zhou Dynasty was a Chinese dynasty that followed the Shang Dynasty and preceded the Qin Dynasty. Although the Zhou Dynasty lasted longer than any other dynasty in Chinese history, the actual political and military control of China by the Ji family lasted only until 771 BC, a period known as...

(c. 1050 BCE – 256 BCE) previous inventions of the blast furnace

Blast furnace

A blast furnace is a type of metallurgical furnace used for smelting to produce industrial metals, generally iron.In a blast furnace, fuel and ore and flux are continuously supplied through the top of the furnace, while air is blown into the bottom of the chamber, so that the chemical reactions...

and cupola furnace

Cupola furnace

A Cupola or Cupola furnace is a melting device used in foundries that can be used to melt cast iron, ni-resist iron and some bronzes. The cupola can be made almost any practical size. The size of a cupola is expressed in diameters and can range from . The overall shape is cylindrical and the...

to make pig iron

Pig iron

Pig iron is the intermediate product of smelting iron ore with a high-carbon fuel such as coke, usually with limestone as a flux. Charcoal and anthracite have also been used as fuel...

and cast iron

Cast iron

Cast iron is derived from pig iron, and while it usually refers to gray iron, it also identifies a large group of ferrous alloys which solidify with a eutectic. The color of a fractured surface can be used to identify an alloy. White cast iron is named after its white surface when fractured, due...

, respectively, the Han period saw the development of steel

Steel

Steel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten...

and wrought iron

Wrought iron

thumb|The [[Eiffel tower]] is constructed from [[puddle iron]], a form of wrought ironWrought iron is an iron alloy with a very low carbon...

by use of the finery forge

Finery forge

Iron tapped from the blast furnace is pig iron, and contains significant amounts of carbon and silicon. To produce malleable wrought iron, it needs to undergo a further process. In the early modern period, this was carried out in a finery forge....

and puddling process

Puddling (metallurgy)

Puddling was an Industrial Revolution means of making iron and steel. In the original puddling technique, molten iron in a reverberatory furnace was stirred with rods, which were consumed in the process...

. With the drilling of deep borehole

Borehole

A borehole is the generalized term for any narrow shaft bored in the ground, either vertically or horizontally. A borehole may be constructed for many different purposes, including the extraction of water or other liquid or gases , as part of a geotechnical investigation, environmental site...

s into the earth, the Chinese used not only derrick

Derrick

A derrick is a lifting device composed of one tower, or guyed mast such as a pole which is hinged freely at the bottom. It is controlled by lines powered by some means such as man-hauling or motors, so that the pole can move in all four directions. A line runs up it and over its top with a hook on...

s to lift brine

Brine

Brine is water, saturated or nearly saturated with salt .Brine is used to preserve vegetables, fruit, fish, and meat, in a process known as brining . Brine is also commonly used to age Halloumi and Feta cheeses, or for pickling foodstuffs, as a means of preserving them...

up to the surface to be boiled into salt

Salt

In chemistry, salts are ionic compounds that result from the neutralization reaction of an acid and a base. They are composed of cations and anions so that the product is electrically neutral...

, but also set up bamboo-crafted pipeline transport

Pipeline transport

Pipeline transport is the transportation of goods through a pipe. Most commonly, liquids and gases are sent, but pneumatic tubes that transport solid capsules using compressed air are also used....

systems which brought natural gas

Natural gas

Natural gas is a naturally occurring gas mixture consisting primarily of methane, typically with 0–20% higher hydrocarbons . It is found associated with other hydrocarbon fuel, in coal beds, as methane clathrates, and is an important fuel source and a major feedstock for fertilizers.Most natural...

as fuel to the furnaces. Smelting techniques were enhanced with inventions such as the waterwheel-powered bellows

Bellows

A bellows is a device for delivering pressurized air in a controlled quantity to a controlled location.Basically, a bellows is a deformable container which has an outlet nozzle. When the volume of the bellows is decreased, the air escapes through the outlet...

; the resulting widespread distribution of iron tools facilitated the growth of agriculture. For tilling the soil

Tillage

Tillage is the agricultural preparation of the soil by mechanical agitation of various types, such as digging, stirring, and overturning. Examples of human-powered tilling methods using hand tools include shovelling, picking, mattock work, hoeing, and raking...

and planting straight rows of crops, the improved heavy-moldboard plough with three iron plowshare

Plowshare

In agriculture, a plowshare is a component of a plow . It is the cutting or leading edge of a moldboard which closely follows the coulter when plowing....

s and sturdy multiple-tube iron seed drill

Seed drill

A seed drill is a sowing device that precisely positions seeds in the soil and then covers them. Before the introduction of the seed drill, the common practice was to plant seeds by hand. Besides being wasteful, planting was very imprecise and led to a poor distribution of seeds, leading to low...

were invented in the Han, which greatly enhanced production yields and thus sustained population growth. The method of supplying irrigation

Irrigation

Irrigation may be defined as the science of artificial application of water to the land or soil. It is used to assist in the growing of agricultural crops, maintenance of landscapes, and revegetation of disturbed soils in dry areas and during periods of inadequate rainfall...

ditches with water was improved with the invention of the mechanical chain pump powered by the rotation of a waterwheel or draft animals, which could transport irrigation water up elevated terrains. The waterwheel was also used for operating trip hammer

Trip hammer

A trip hammer, also known as a helve hammer, is a massive powered hammer used in:* agriculture to facilitate the labor of pounding, decorticating and polishing of grain;...

s in pounding grain and in rotating the metal rings of the mechanical-driven astronomical armillary sphere

Armillary sphere

An armillary sphere is a model of objects in the sky , consisting of a spherical framework of rings, centred on Earth, that represent lines of celestial longitude and latitude and other astronomically important features such as the ecliptic...

representing the celestial sphere

Celestial sphere

In astronomy and navigation, the celestial sphere is an imaginary sphere of arbitrarily large radius, concentric with the Earth and rotating upon the same axis. All objects in the sky can be thought of as projected upon the celestial sphere. Projected upward from Earth's equator and poles are the...

around the Earth.

The quality of life was improved with many Han inventions. The Han Chinese had hempen-bound bamboo scrolls to write on, yet by the 2nd century CE had invented the papermaking

Papermaking

Papermaking is the process of making paper, a substance which is used universally today for writing and packaging.In papermaking a dilute suspension of fibres in water is drained through a screen, so that a mat of randomly interwoven fibres is laid down. Water is removed from this mat of fibres by...

process which created a writing medium that was both cheap and easy to produce. The invention of the wheelbarrow

Wheelbarrow

A wheelbarrow is a small hand-propelled vehicle, usually with just one wheel, designed to be pushed and guided by a single person using two handles to the rear, or by a sail to push the ancient wheelbarrow by wind. The term "wheelbarrow" is made of two words: "wheel" and "barrow." "Barrow" is a...

aided in the hauling of heavy loads. The maritime junk ship

Junk (ship)

A junk is an ancient Chinese sailing vessel design still in use today. Junks were developed during the Han Dynasty and were used as sea-going vessels as early as the 2nd century AD. They evolved in the later dynasties, and were used throughout Asia for extensive ocean voyages...

and stern-mounted steering rudder

Rudder

A rudder is a device used to steer a ship, boat, submarine, hovercraft, aircraft or other conveyance that moves through a medium . On an aircraft the rudder is used primarily to counter adverse yaw and p-factor and is not the primary control used to turn the airplane...

enabled the Chinese to venture out of calmer waters of interior lakes and rivers and into the open sea. The invention of the grid reference

Grid reference

Grid references define locations on maps using Cartesian coordinates. Grid lines on maps define the coordinate system, and are numbered to provide a unique reference to features....

for maps and raised-relief map

Raised-relief map

A raised-relief map or terrain model is a three-dimensional representation, usually of terrain. When representing terrain, the elevation dimension is usually exaggerated by a factor between five and ten; this facilitates the visual recognition of terrain features.-History:In his 1665 paper for the...

allowed the Chinese to better navigate their terrain. In medicine

Traditional Chinese medicine

Traditional Chinese Medicine refers to a broad range of medicine practices sharing common theoretical concepts which have been developed in China and are based on a tradition of more than 2,000 years, including various forms of herbal medicine, acupuncture, massage , exercise , and dietary therapy...

, they used new herbal remedies

Chinese herbology

Chinese Herbology is the theory of Traditional Chinese herbal therapy, which accounts for the majority of treatments in Traditional Chinese medicine ....

to cure illnesses, calisthenics

Calisthenics

Calisthenics are a form of aerobic exercise consisting of a variety of simple, often rhythmical, movements, generally using multiple equipment or apparatus. They are intended to increase body strength and flexibility with movements such as bending, jumping, swinging, twisting or kicking, using...

to keep physically fit, and regulated diet

Diet (nutrition)

In nutrition, diet is the sum of food consumed by a person or other organism. Dietary habits are the habitual decisions an individual or culture makes when choosing what foods to eat. With the word diet, it is often implied the use of specific intake of nutrition for health or weight-management...

s to avoid diseases. Authorities in the capital were warned ahead of time of the direction of sudden earthquakes with the invention of the seismometer

Seismometer

Seismometers are instruments that measure motions of the ground, including those of seismic waves generated by earthquakes, volcanic eruptions, and other seismic sources...

that was tripped by a vibration-sensitive pendulum

Pendulum

A pendulum is a weight suspended from a pivot so that it can swing freely. When a pendulum is displaced from its resting equilibrium position, it is subject to a restoring force due to gravity that will accelerate it back toward the equilibrium position...

device. To mark the passing of the seasons and special occasions, the Han Chinese utilized two variations

Chinese calendar

The Chinese calendar is a lunisolar calendar, incorporating elements of a lunar calendar with those of a solar calendar. It is not exclusive to China, but followed by many other Asian cultures as well...

of the lunisolar calendar

Lunisolar calendar

A lunisolar calendar is a calendar in many cultures whose date indicates both the moon phase and the time of the solar year. If the solar year is defined as a tropical year then a lunisolar calendar will give an indication of the season; if it is taken as a sidereal year then the calendar will...

, which were established due to efforts in astronomy

Chinese astronomy

Astronomy in China has a very long history, with historians considering that "they [the Chinese] were the most persistent and accurate observers of celestial phenomena anywhere in the world before the Arabs."...

and mathematics

Chinese mathematics

Mathematics in China emerged independently by the 11th century BC. The Chinese independently developed very large and negative numbers, decimals, a place value decimal system, a binary system, algebra, geometry, and trigonometry....

. Han-era Chinese advancements in mathematics include the discovery of square root

Square root

In mathematics, a square root of a number x is a number r such that r2 = x, or, in other words, a number r whose square is x...

s, cube roots, the Pythagorean theorem

Pythagorean theorem

In mathematics, the Pythagorean theorem or Pythagoras' theorem is a relation in Euclidean geometry among the three sides of a right triangle...

, Gaussian elimination

Gaussian elimination

In linear algebra, Gaussian elimination is an algorithm for solving systems of linear equations. It can also be used to find the rank of a matrix, to calculate the determinant of a matrix, and to calculate the inverse of an invertible square matrix...

, the Horner scheme

Horner scheme

In numerical analysis, the Horner scheme , named after William George Horner, is an algorithm for the efficient evaluation of polynomials in monomial form. Horner's method describes a manual process by which one may approximate the roots of a polynomial equation...

, improved calculations of pi
Pi
' is a mathematical constant that is the ratio of any circle's circumference to its diameter. is approximately equal to 3.14. Many formulae in mathematics, science, and engineering involve , which makes it one of the most important mathematical constants...

, and negative numbers. Hundreds of new roads and canals were built to facilitate transport, commerce, tax collection, communication, and movement of military troops. The Han-era Chinese also employed several types of bridges to cross waterways and deep gorges, such as beam bridge

Beam bridge

Beam bridges are the most simple of structural forms being supported by an abutment at each end of the deck. No moments are transferred through the support hence their structural type is known as simply supported....

s, arch bridge

Arch bridge

An arch bridge is a bridge with abutments at each end shaped as a curved arch. Arch bridges work by transferring the weight of the bridge and its loads partially into a horizontal thrust restrained by the abutments at either side...

s, simple suspension bridge

Simple suspension bridge

A simple suspension bridge is an early type of bridge that is supported entirely from anchors at either end, and has no towers or piers. However, it may have saddles...

s, and pontoon bridge

Pontoon bridge

A pontoon bridge or floating bridge is a bridge that floats on water and in which barge- or boat-like pontoons support the bridge deck and its dynamic loads. While pontoon bridges are usually temporary structures, some are used for long periods of time...

s. Han ruins of defensive city walls

Chinese city wall

Chinese city walls refer to civic defensive systems used to protect towns and cities in China in pre-modern times. The system consisted of walls, towers, and gates, which were often built to a uniform standard throughout the Empire....

made of brick

Brick

A brick is a block of ceramic material used in masonry construction, usually laid using various kinds of mortar. It has been regarded as one of the longest lasting and strongest building materials used throughout history.-History:...

or rammed earth

Rammed earth

Rammed earth, also known as taipa , tapial , and pisé , is a technique for building walls using the raw materials of earth, chalk, lime and gravel. It is an ancient building method that has seen a revival in recent years as people seek more sustainable building materials and natural building methods...

still stand today.

Modern perspectives on science and technology during Han

Jin Guantao, a professor of the Institute of Chinese Studies at the Chinese University of Hong Kong

Chinese University of Hong Kong

The Chinese University of Hong Kong is a research-led university in Hong Kong.CUHK is the only tertiary education institution in Hong Kong with Nobel Prize winners on its faculty, including Chen Ning Yang, James Mirrlees, Robert Alexander Mundell and Charles K. Kao...

, Fan Hongye, a research fellow with the Chinese Academy of Sciences

Chinese Academy of Sciences

The Chinese Academy of Sciences , formerly known as Academia Sinica, is the national academy for the natural sciences of the People's Republic of China. It is an institution of the State Council of China. It is headquartered in Beijing, with institutes all over the People's Republic of China...

' Institute of Science Policy and Managerial Science, and Liu Qingfeng, a professor of the Institute of Chinese Culture at the Chinese University of Hong Kong, assert that the latter part of the Han Dynasty was a unique period in the history of premodern Chinese science and technology. They compare it to the incredible pace of scientific and technological growth

Technology of the Song Dynasty

The Song Dynasty provided some of the most significant technological advances in Chinese history, many of which came from talented statesmen drafted by the government through imperial examinations....

during the Song Dynasty

Song Dynasty

The Song Dynasty was a ruling dynasty in China between 960 and 1279; it succeeded the Five Dynasties and Ten Kingdoms Period, and was followed by the Yuan Dynasty. It was the first government in world history to issue banknotes or paper money, and the first Chinese government to establish a...

(960–1279 CE). However, they also argue that without the influence of proto-scientific precepts in the ancient philosophy of Mohism

Mohism

Mohism or Moism was a Chinese philosophy developed by the followers of Mozi , 470 BC–c.391 BC...

, Chinese science continued to lack a definitive structure:

From the middle and late Eastern Han to the early Wei and Jin dynasties, the net growth of ancient Chinese science and technology experienced a peak (second only to that of the Northern Song dynasty). . .Han studies of the Confucian classics, which for a long time had hindered the socialization of science, were declining. If Mohism, rich in scientific thought, had rapidly grown and strengthened, the situation might have been very favorable to the development of a scientific structure. However, this did not happen because the seeds of the primitive structure of science were never formed. During the late Eastern Han, disastrous upheavals again occurred in the process of social transformation, leading to the greatest social disorder in Chinese history. One can imagine the effect of this calamity on science.

Joseph Needham

Noel Joseph Terence Montgomery Needham, CH, FRS, FBA , also known as Li Yuese , was a British scientist, historian and sinologist known for his scientific research and writing on the history of Chinese science. He was elected a fellow of the Royal Society in 1941, and as a fellow of the British...

(1900–1995), a late Professor from the University of Cambridge

University of Cambridge

The University of Cambridge is a public research university located in Cambridge, United Kingdom. It is the second-oldest university in both the United Kingdom and the English-speaking world , and the seventh-oldest globally...

and author of the groundbreaking Science and Civilization in China series, stated that the "Han time (especially the Later Han) was one of the relatively important periods as regards the history of science in China." He noted the advancements during Han of astronomy

Chinese astronomy

and calendrical

Chinese calendar

sciences, the "beginnings of systematic botany

Botany

Botany, plant science, or plant biology is a branch of biology that involves the scientific study of plant life. Traditionally, botany also included the study of fungi, algae and viruses...

and zoology

Zoology

Zoology |zoölogy]]), is the branch of biology that relates to the animal kingdom, including the structure, embryology, evolution, classification, habits, and distribution of all animals, both living and extinct...

", as well as the philosophical skepticism

Philosophical skepticism

Philosophical skepticism is both a philosophical school of thought and a method that crosses disciplines and cultures. Many skeptics critically examine the meaning systems of their times, and this examination often results in a position of ambiguity or doubt...

and rationalist thought

Rationalism

In epistemology and in its modern sense, rationalism is "any view appealing to reason as a source of knowledge or justification" . In more technical terms, it is a method or a theory "in which the criterion of the truth is not sensory but intellectual and deductive"...

embodied in Han works such as the Lunheng
Lunheng
The Lunheng is a wide-ranging Chinese classic text containing critical essays by Wang Chong on natural science, Chinese mythology, philosophy, and literature.-Title:...

by the philosopher Wang Chong

Wang Chong

Wang Chong , courtesy name Zhongren , was a Chinese philosopher active during the Han Dynasty. He developed a rational, secular, naturalistic and mechanistic account of the world and of human beings and gave a materialistic explanation of the origin of the universe. His main work was the Lùnhéng...

(27–100 CE).

Writing materials

The most common writing mediums found in archaeological digs from ancient sites predating the Han period are shells and bones

Oracle bone

Oracle bones are pieces of bone normally from ox scapula or turtle plastron which were used for divination chiefly during the late Shang Dynasty. The bones were first inscribed with divination in oracle bone script by using a bronze pin, and then heated until crack lines appeared in which the...

as well as bronzewares

Chinese bronzes

Bronzes are some of the most important pieces of Chinese art, warranting an entire separate catalogue in the Imperial art collections. The Chinese Bronze Age began in the Xia Dynasty, and bronze ritual containers form the bulk of the collection of Chinese antiques, reaching its zenith during the...

. In the beginning of the Han period, the chief writing mediums were bamboo (Chinese: 竹簡) and clay tablet

Clay tablet

In the Ancient Near East, clay tablets were used as a writing medium, especially for writing in cuneiform, throughout the Bronze Age and well into the Iron Age....

s, silk

Silk

Silk is a natural protein fiber, some forms of which can be woven into textiles. The best-known type of silk is obtained from the cocoons of the larvae of the mulberry silkworm Bombyx mori reared in captivity...

cloth, and rolled scrolls made of strips of bamboo

Bamboo

Bamboo is a group of perennial evergreens in the true grass family Poaceae, subfamily Bambusoideae, tribe Bambuseae. Giant bamboos are the largest members of the grass family....

sewn together with hemp

Hemp

Hemp is mostly used as a name for low tetrahydrocannabinol strains of the plant Cannabis sativa, of fiber and/or oilseed varieties. In modern times, hemp has been used for industrial purposes including paper, textiles, biodegradable plastics, construction, health food and fuel with modest...

en string passed through drilled holes (册) and secured with clay stamps. The written characters

Chinese character

Chinese characters are logograms used in the writing of Chinese and Japanese , less frequently Korean , formerly Vietnamese , or other languages...

on these narrow flat strips of bamboo were arranged into vertical columns.

While maps drawn in ink on flat silk cloths have been found in the tomb of the Marquess of Dai

Mawangdui Silk Texts

The Mawangdui Silk Texts are texts of Chinese philosophical and medical works written on silk and found at Mawangdui in China in 1973. They include some of the earliest attested manuscripts of existing texts such as the I Ching, two copies of the Tao Te Ching, one similar copy of Strategies of the...

(interred in 168 BCE at Mawangdui, Hunan

Hunan

' is a province of South-Central China, located to the south of the middle reaches of the Yangtze River and south of Lake Dongting...

province), the earliest known paper

Paper

Paper is a thin material mainly used for writing upon, printing upon, drawing or for packaging. It is produced by pressing together moist fibers, typically cellulose pulp derived from wood, rags or grasses, and drying them into flexible sheets....

map found in China, dated 179–41 BCE and located at Fangmatan (near Tianshui

Tianshui

Tianshui is the second largest city in Gansu province in northwest China. Its population is approximately 3,500,000.Tianshui lies along the route of the ancient Northern Silk Road at the Wei River, through which much of trade occurred between China and the west...

, Gansu

Gansu

' is a province located in the northwest of the People's Republic of China.It lies between the Tibetan and Huangtu plateaus, and borders Mongolia, Inner Mongolia, and Ningxia to the north, Xinjiang and Qinghai to the west, Sichuan to the south, and Shaanxi to the east...

province), is incidentally the oldest known piece of paper. Yet Chinese hempen paper of the Western Han and early Eastern Han eras was of a coarse quality and used primarily as wrapping paper

Wrapping Paper

"Wrapping Paper" is a song with music composed by Jack Bruce and lyrics by Pete Brown, performed by Cream and originally released as a single in 1966 with "Cat's Squirrel" as the B side. It is featured on The Very Best of Cream...

. The papermaking

Papermaking

process was not formally introduced until the Eastern Han court eunuch Cai Lun

Cai Lun

Cai Lun , courtesy name Jingzhong , was a Chinese eunuch. He is traditionally regarded as the inventor of paper and the papermaking process, in forms recognizable in modern times as paper...

(50–121 CE) created a process in 105 CE where mulberry tree bark, hemp, old linens, and fish nets were boiled together to make a pulp that was pounded, stirred in water, and then dunked with a wooden sieve containing a reed

Reed (plant)

Reed is a generic polyphyletic botanical term used to describe numerous tall, grass-like plants of wet places, which are the namesake vegetation of reed beds...

mat that was shaken, dried, and bleached into sheets of paper. The oldest known piece of paper with writing on it comes from the ruins of a Chinese watchtower

Watchtower

A watchtower is a type of fortification used in many parts of the world. It differs from a regular tower in that its primary use is military, and from a turret in that it is usually a freestanding structure. Its main purpose is to provide a high, safe place from which a sentinel or guard may...

at Tsakhortei, Alxa League

Alxa League

Alxa League is one of 12 prefecture level divisions and three extant leagues of Inner Mongolia. The league borders Mongolia to the north, Bayan Nur to the northeast, Wuhai and Ordos to the east, Ningxia to the southeast, and Gansu to the south and west. The capital is Bayan Hot in the aimag's...

, Inner Mongolia

Inner Mongolia

Inner Mongolia is an autonomous region of the People's Republic of China, located in the northern region of the country. Inner Mongolia shares an international border with the countries of Mongolia and the Russian Federation...

, dated precisely 110 CE when the Han garrison abandoned the area following a nomadic Xiongnu

Xiongnu

The Xiongnu were ancient nomadic-based people that formed a state or confederation north of the agriculture-based empire of the Han Dynasty. Most of the information on the Xiongnu comes from Chinese sources...

attack. By the 3rd century, paper became one of China's chief writing mediums.

Ceramics

The Han Dynasty ceramics industry was upheld by private businesses as well as local government agencies. Ceramics were used in domestic wares and utensils as well as construction materials for roof tile

Tile

A tile is a manufactured piece of hard-wearing material such as ceramic, stone, metal, or even glass. Tiles are generally used for covering roofs, floors, walls, showers, or other objects such as tabletops...

s and brick

Brick

s.

Han Dynasty grey pottery

Pottery

Pottery is the material from which the potteryware is made, of which major types include earthenware, stoneware and porcelain. The place where such wares are made is also called a pottery . Pottery also refers to the art or craft of the potter or the manufacture of pottery...

—its color derived from the clay

Clay

Clay is a general term including many combinations of one or more clay minerals with traces of metal oxides and organic matter. Geologic clay deposits are mostly composed of phyllosilicate minerals containing variable amounts of water trapped in the mineral structure.- Formation :Clay minerals...

that was used—was superior to earlier Chinese grey pottery due to the Han people's use of larger kiln

Kiln

A kiln is a thermally insulated chamber, or oven, in which a controlled temperature regime is produced. Uses include the hardening, burning or drying of materials...

chambers, longer firing tunnels, and improved chimney designs. Kilns of the Han Dynasty making grey pottery were able to reach firing temperatures above 1000°C (1832°F). However, hard southern Chinese pottery made from a dense adhesive clay native only in the south (i.e. Guangdong

Guangdong

Guangdong is a province on the South China Sea coast of the People's Republic of China. The province was previously often written with the alternative English name Kwangtung Province...

, Guangxi

Guangxi

Guangxi, formerly romanized Kwangsi, is a province of southern China along its border with Vietnam. In 1958, it became the Guangxi Zhuang Autonomous Region of the People's Republic of China, a region with special privileges created specifically for the Zhuang people.Guangxi's location, in...

, Hunan

Hunan

' is a province of South-Central China, located to the south of the middle reaches of the Yangtze River and south of Lake Dongting...

, Jiangxi

Jiangxi

' is a southern province in the People's Republic of China. Spanning from the banks of the Yangtze River in the north into hillier areas in the south, it shares a border with Anhui to the north, Zhejiang to the northeast, Fujian to the east, Guangdong to the south, Hunan to the west, and Hubei to...

, Fujian

Fujian

' , formerly romanised as Fukien or Huguing or Foukien, is a province on the southeast coast of mainland China. Fujian is bordered by Zhejiang to the north, Jiangxi to the west, and Guangdong to the south. Taiwan lies to the east, across the Taiwan Strait...

, Zhejiang

Zhejiang

Zhejiang is an eastern coastal province of the People's Republic of China. The word Zhejiang was the old name of the Qiantang River, which passes through Hangzhou, the provincial capital...

, and southern Jiangsu

Jiangsu

' is a province of the People's Republic of China, located along the east coast of the country. The name comes from jiang, short for the city of Jiangning , and su, for the city of Suzhou. The abbreviation for this province is "苏" , the second character of its name...

) was fired at even higher temperatures than grey pottery during the Han. Glazed pottery

Ceramic glaze

Glaze is a layer or coating of a vitreous substance which has been fired to fuse to a ceramic object to color, decorate, strengthen or waterproof it.-Use:...

of the Shang

Shang Dynasty

The Shang Dynasty or Yin Dynasty was, according to traditional sources, the second Chinese dynasty, after the Xia. They ruled in the northeastern regions of the area known as "China proper" in the Yellow River valley...

(c. 1600 – c. 1050 BCE) and Zhou

Zhou Dynasty

(c. 1050 – 256 BCE) dynasties were fired at high temperatures, but by the mid Western Han (206 BCE – 9 CE), a brown-glazed ceramic was made which was fired at the low temperature of 800°C (1472°F), followed by a green-glazed ceramic which became popular in the Eastern Han (25–220 CE).

Wang Zhongshu states that the light-green stoneware

Stoneware

Stoneware is a vitreous or semi-vitreous ceramic ware with a fine texture. Stoneware is made from clay that is then fired in a kiln, whether by an artisan to make homeware, or in an industrial kiln for mass-produced or specialty products...

known as celadon

Celadon

Celadon is a term for ceramics denoting both a type of glaze and a ware of a specific color, also called celadon. This type of ware was invented in ancient China, such as in the Zhejiang province...

was thought to exist only since the Three Kingdoms

Three Kingdoms

The Three Kingdoms period was a period in Chinese history, part of an era of disunity called the "Six Dynasties" following immediately the loss of de facto power of the Han Dynasty rulers. In a strict academic sense it refers to the period between the foundation of the state of Wei in 220 and the...

(220–265 CE) period onwards, but argues that ceramic shards found at Eastern Han (25–220 CE) sites of Zhejiang province can be classified as celadon

Celadon

Celadon is a term for ceramics denoting both a type of glaze and a ware of a specific color, also called celadon. This type of ware was invented in ancient China, such as in the Zhejiang province...

. However, Richard Dewar argues that true celadon was not created in China until the early Song Dynasty

Song Dynasty

(960–1279) when Chinese kilns were able to reach a minimum furnace temperature of 1260°C (2300°F), with a preferred range of 1285° to 1305°C (2345° to 2381°F) for celadon.

Metallurgy

Furnaces and smelting techniques

A blast furnace

Blast furnace

converts raw iron ore into pig iron

Pig iron

Pig iron is the intermediate product of smelting iron ore with a high-carbon fuel such as coke, usually with limestone as a flux. Charcoal and anthracite have also been used as fuel...

, which can be remelted in a cupola furnace

Cupola furnace

to produce cast iron

Cast iron

. The earliest specimens of cast iron found in China date to the 5th century BCE during the late Spring and Autumn Period, yet the oldest discovered blast furnaces date to the 3rd century BCE and the majority date to the period after Emperor Wu of Han

Emperor Wu of Han

Emperor Wu of Han , , personal name Liu Che , was the seventh emperor of the Han Dynasty of China, ruling from 141 BC to 87 BC. Emperor Wu is best remembered for the vast territorial expansion that occurred under his reign, as well as the strong and centralized Confucian state he organized...

(r. 141–87 BCE) established a government monopoly over the iron industry

Economy of the Han Dynasty

The Han Dynasty of ancient China experienced contrasting periods of economic prosperity and decline. It is normally divided into three periods: Western Han , the Xin Dynasty , and Eastern Han . The Xin Dynasty, established by the former regent Wang Mang, formed a brief interregnum between lengthy...

in 117 BCE (most of the discovered iron works sites built before this date were merely foundries

Foundry

A foundry is a factory that produces metal castings. Metals are cast into shapes by melting them into a liquid, pouring the metal in a mold, and removing the mold material or casting after the metal has solidified as it cools. The most common metals processed are aluminum and cast iron...

which recast iron that had been smelt elsewhere). Iron ore smelted in blast furnaces during the Han was rarely if ever cast directly into permanent molds; instead, the pig iron scraps were remelted in the cupola furnace to make cast iron. Cupola furnaces utilized a cold blast

Cold blast

Cold blast, in ironmaking, refers to a furnace where air is not preheated before being blown into the furnace. This represents the earliest stage in the development of ironmaking...

traveling through tuyere

Tuyere

A tuyere, also can be spelled as tuyère, is a tube, nozzle or pipe through which air is blown into a furnace or hearth.Air or oxygen is injected into a hearth under pressure from bellows or a blast engine or other devices...

pipes from the bottom and over the top where the charge of charcoal

Charcoal

Charcoal is the dark grey residue consisting of carbon, and any remaining ash, obtained by removing water and other volatile constituents from animal and vegetation substances. Charcoal is usually produced by slow pyrolysis, the heating of wood or other substances in the absence of oxygen...

and pig iron was introduced. The air traveling through the tuyere pipes thus became a hot blast

Hot blast

Hot blast refers to the preheating of air blown into a blast furnace or other metallurgical process. This has the result of considerably reducing the fuel consumed in the process...

once it reached the bottom of the furnace.

Although Chinese civilization lacked the bloomery

Bloomery

A bloomery is a type of furnace once widely used for smelting iron from its oxides. The bloomery was the earliest form of smelter capable of smelting iron. A bloomery's product is a porous mass of iron and slag called a bloom. This mix of slag and iron in the bloom is termed sponge iron, which...

, the Han Chinese were able to make wrought iron

Wrought iron

thumb|The [[Eiffel tower]] is constructed from [[puddle iron]], a form of wrought ironWrought iron is an iron alloy with a very low carbon...

when they injected too much oxygen

Oxygen

Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...

into the cupola furnace, causing decarburization

Decarburization

Decarburization is the process opposite to carburization, namely aimed at decreasing the content of carbon in metals . Decarburization occurs when Carbon in the metal reacts with gasses present in the atmosphere...

. The Han-era Chinese were also able to convert cast iron and pig iron into wrought iron and steel

Steel

by using the finery forge

Finery forge

and puddling process

Puddling (metallurgy)

, the earliest specimens of such dating to the 2nd century BCE and found at Tieshengguo near Mount Song

Mount Song

Mount Song, known in Chinese as Song Shan , is one of the Five Sacred Mountains of Taoism and is located in Henan province on the south bank of the Yellow River in China...

of Henan

Henan

Henan , is a province of the People's Republic of China, located in the central part of the country. Its one-character abbreviation is "豫" , named after Yuzhou , a Han Dynasty state that included parts of Henan...

province. The semisubterranean walls of these furnaces were lined with refractory

Refractory

A refractory material is one that retains its strength at high temperatures. ASTM C71 defines refractories as "non-metallic materials having those chemical and physical properties that make them applicable for structures, or as components of systems, that are exposed to environments above...

bricks and had bottoms made of refractory clay. Besides charcoal made of wood, Wang Zhongshu states that another furnace fuel used during the Han were "coal cakes", a mixture of coal

Coal

Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams. The harder forms, such as anthracite coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure...

powder, clay, and quartz

Quartz

Quartz is the second-most-abundant mineral in the Earth's continental crust, after feldspar. It is made up of a continuous framework of SiO4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall formula SiO2. There are many different varieties of quartz,...

Use of steel, iron, and bronze

Donald B. Wagner writes that most domestic iron tools and implements produced during the Han were made of cheaper and more brittle cast iron, whereas the military preferred to use wrought iron and steel weaponry due to their more durable qualities. During the Han Dynasty, the typical 0.5 m (1.5 ft) bronze

Bronze

Bronze is a metal alloy consisting primarily of copper, usually with tin as the main additive. It is hard and brittle, and it was particularly significant in antiquity, so much so that the Bronze Age was named after the metal...

sword found in the Warring States Period

Warring States Period

The Warring States Period , also known as the Era of Warring States, or the Warring Kingdoms period, covers the Iron Age period from about 475 BC to the reunification of China under the Qin Dynasty in 221 BC...

was gradually replaced with an iron sword

Chinese swords

Swords have a long history in China. Stone swords were used in prehistoric times. Bronze swords have been traced back to the bronze daggers of the Shang period,. Bronze long swords suddenly appeared during the mid-third century BC. Later swords were made of iron or steel. These metals were...

measuring roughly 1 m (3 ft) in length. The ancient dagger-axe

Dagger-axe

The dagger-axe is a type of weapon that was in use from Shang dynasty until at least Han dynasty China. It consists of a dagger-shaped blade made of jade , bronze, or later iron, mounted by the tang of the dagger to a perpendicular wooden shaft with a spear point...

(ge) made of bronze was still used by Han soldiers, although it was gradually phased out by iron spears and iron ji halberds

Ji (halberd)

The ji , the Chinese halberd, was used as a military weapon in one form or another from at least as early as the Shang dynasty until the end of the Qing dynasty. They are still used for training purposes by many Chinese martial arts...

. Even arrowhead

Arrowhead

An arrowhead is a tip, usually sharpened, added to an arrow to make it more deadly or to fulfill some special purpose. Historically arrowheads were made of stone and of organic materials; as human civilization progressed other materials were used...

s, which were traditionally made of bronze, gradually only had a bronze tip and iron shaft, until the end of the Han when the entire arrowhead was made solely of iron. Farmers, carpenter

Carpenter

A carpenter is a skilled craftsperson who works with timber to construct, install and maintain buildings, furniture, and other objects. The work, known as carpentry, may involve manual labor and work outdoors....

s, bamboo craftsmen, stonemasons, and rammed earth

Rammed earth

builders had at their disposal iron tools such as the plowshare

Plowshare

In agriculture, a plowshare is a component of a plow . It is the cutting or leading edge of a moldboard which closely follows the coulter when plowing....

, pickaxe

Pickaxe

A pickaxe or pick is a hand tool with a hard head attached perpendicular to the handle.Some people make the distinction that a pickaxe has a head with a pointed end and a flat end, and a pick has both ends pointed, or only one end; but most people use the words to mean the same thing.The head is...

, spade

Spade

A spade is a tool designed primarily for the purpose of digging or removing earth. Early spades were made of riven wood. After the art of metalworking was discovered, spades were made with sharper tips of metal. Before the advent of metal spades manual labor was less efficient at moving earth,...

, shovel

Shovel

A shovel is a tool for digging, lifting, and moving bulk materials, such as soil, coal, gravel, snow, sand, or ore. Shovels are extremely common tools that are used extensively in agriculture, construction, and gardening....

, hoe

Hoe (tool)

A hoe is an ancient and versatile agricultural tool used to move small amounts of soil. Common goals include weed control by agitating the surface of the soil around plants, piling soil around the base of plants , creating narrow furrows and shallow trenches for planting seeds and bulbs, to chop...

, sickle

Sickle

A sickle is a hand-held agricultural tool with a variously curved blade typically used for harvesting grain crops or cutting succulent forage chiefly for feeding livestock . Sickles have also been used as weapons, either in their original form or in various derivations.The diversity of sickles that...

, axe

Axe

The axe, or ax, is an implement that has been used for millennia to shape, split and cut wood; to harvest timber; as a weapon; and as a ceremonial or heraldic symbol...

, adze

Adze

An adze is a tool used for smoothing or carving rough-cut wood in hand woodworking. Generally, the user stands astride a board or log and swings the adze downwards towards his feet, chipping off pieces of wood, moving backwards as they go and leaving a relatively smooth surface behind...

, hammer

Hammer

A hammer is a tool meant to deliver an impact to an object. The most common uses are for driving nails, fitting parts, forging metal and breaking up objects. Hammers are often designed for a specific purpose, and vary widely in their shape and structure. The usual features are a handle and a head,...

, chisel

Chisel

A chisel is a tool with a characteristically shaped cutting edge of blade on its end, for carving or cutting a hard material such as wood, stone, or metal. The handle and blade of some types of chisel are made of metal or wood with a sharp edge in it.In use, the chisel is forced into the material...

, knife

Knife

A knife is a cutting tool with an exposed cutting edge or blade, hand-held or otherwise, with or without a handle. Knives were used at least two-and-a-half million years ago, as evidenced by the Oldowan tools...

, saw

Saw

A saw is a tool that uses a hard blade or wire with an abrasive edge to cut through softer materials. The cutting edge of a saw is either a serrated blade or an abrasive...

, scratch awl

Scratch awl

A scratch awl is a woodworking layout and point-making tool. It is used to scribe a line to be followed by a hand saw or chisel when making woodworking joints and other operations....

, and nails. Common iron commodities found in Han Dynasty homes included tripods, stove

Stove

A stove is an enclosed heated space. The term is commonly taken to mean an enclosed space in which fuel is burned to provide heating, either to heat the space in which the stove is situated or to heat the stove itself, and items placed on it...

s, cooking pots

Cookware and bakeware

Cookware and bakeware are types of food preparation containers commonly found in the kitchen. Cookware comprises cooking vessels, such as saucepans and frying pans, intended for use on a stove or range cooktop. Bakeware comprises cooking vessels intended for use inside an oven...

, belt buckle

Belt buckle

A belt buckle is a buckle, a clasp for fastening two ends, as of straps or a belt, in which a device attached to one of the ends is fitted or coupled to the other. The word enters Middle English via Old French and the Latin buccula or "cheek-strap," as for a helmet...

s, tweezers

Tweezers

Tweezers are tools used for picking up and manipulating objects too small to be easily handled with the human hands. They are probably derived from tongs, pincers, or scissors-like pliers used to grab or hold hot objects since the dawn of recorded history...

, fire tongs

Tongs

Tongs are used for gripping and lifting tools, of which there are many forms adapted to their specific use. Some are merely large pincers or nippers, but the greatest number fall into three classes:...

, scissors

Scissors

Scissors are hand-operated cutting instruments. They consist of a pair of metal blades pivoted so that the sharpened edges slide against each other when the handles opposite to the pivot are closed. Scissors are used for cutting various thin materials, such as paper, cardboard, metal foil, thin...

, kitchen knives, fish hook

Fish hook

A fish hook is a device for catching fish either by impaling them in the mouth or, more rarely, by snagging the body of the fish. Fish hooks have been employed for centuries by fishermen to catch fresh and saltwater fish. In 2005, the fish hook was chosen by Forbes as one of the top twenty tools...

s, and needles

Sewing needle

A sewing needle is a long slender tool with a pointed tip. The first needles were made of bone or wood; modern ones are manufactured from high carbon steel wire, nickel- or 18K gold plated for corrosion resistance. The highest quality embroidery needles are plated with two-thirds platinum and...

. Mirrors

TLV mirror

A TLV mirror is a type of bronze mirror that was popular during the Han Dynasty in China. They are called TLV mirrors because symbols resembling the letters T, L, and V are engraved into them...

and oil lamp

Oil lamp

An oil lamp is an object used to produce light continuously for a period of time using an oil-based fuel source. The use of oil lamps began thousands of years ago and is continued to this day....

s were often made of either bronze or iron. Coin money minted during the Han was made

Economy of the Han Dynasty

of either copper

Copper

Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...

or copper and tin

Tin

Tin is a chemical element with the symbol Sn and atomic number 50. It is a main group metal in group 14 of the periodic table. Tin shows chemical similarity to both neighboring group 14 elements, germanium and lead and has two possible oxidation states, +2 and the slightly more stable +4...

smelted together to make the bronze alloy.

Tools and methods

Modern archaeologists have unearthed Han iron farming tools throughout China, from Inner Mongolia

Inner Mongolia

in the north to Yunnan

Yunnan

Yunnan is a province of the People's Republic of China, located in the far southwest of the country spanning approximately and with a population of 45.7 million . The capital of the province is Kunming. The province borders Burma, Laos, and Vietnam.Yunnan is situated in a mountainous area, with...

in the south. The spade, shovel, pick, and plow were used for tillage

Tillage

, the hoe for weed

Weed

A weed in a general sense is a plant that is considered by the user of the term to be a nuisance, and normally applied to unwanted plants in human-controlled settings, especially farm fields and gardens, but also lawns, parks, woods, and other areas. More specifically, the term is often used to...

ing, the rake

Rake (tool)

A rake is a broom for outside; an horticultural implement consisting of a toothed bar fixed transversely to a handle, and used to collect leaves, hay, grass, etc., and, in gardening, for loosening the soil, light weeding and levelling, removing dead grass from...

for loosening the soil, and the sickle

Sickle

for harvesting crops. Depending on their size, Han plows were driven by either one ox or two oxen. Oxen were also used to pull the three-legged iron seed drill

Seed drill

(invented in Han China by the 2nd century BCE), which enabled farmers to plant seeds in precise rows instead of casting them out by hand

Sowing

Sowing is the process of planting seeds.-Plants which are usually sown:Among the major field crops, oats, wheat, and rye are sowed, grasses and legumes are seeded, and maize and soybeans are planted...

. While artwork of the Wei

Cao Wei

Cao Wei was one of the states that competed for control of China during the Three Kingdoms period. With the capital at Luoyang, the state was established by Cao Pi in 220, based upon the foundations that his father Cao Cao laid...

(220–265 CE) and Jin (265–420 CE) periods show use of the harrow

Harrow (tool)

In agriculture, a harrow is an implement for breaking up and smoothing out the surface of the soil. In this way it is distinct in its effect from the plough, which is used for deeper tillage. Harrowing is often carried out on fields to follow the rough finish left by ploughing operations...

for breaking up chunks of soil after plowing, it perhaps first appeared in China during the Eastern Han (25–220 CE). Irrigation

Irrigation

works for agriculture included the use of water well

Water well

A water well is an excavation or structure created in the ground by digging, driving, boring or drilling to access groundwater in underground aquifers. The well water is drawn by an electric submersible pump, a trash pump, a vertical turbine pump, a handpump or a mechanical pump...

s, artificial ponds and embankments, dam

Dam

A dam is a barrier that impounds water or underground streams. Dams generally serve the primary purpose of retaining water, while other structures such as floodgates or levees are used to manage or prevent water flow into specific land regions. Hydropower and pumped-storage hydroelectricity are...

s, canal

Canal

Canals are man-made channels for water. There are two types of canal:#Waterways: navigable transportation canals used for carrying ships and boats shipping goods and conveying people, further subdivided into two kinds:...

s, and sluice

Sluice

A sluice is a water channel that is controlled at its head by a gate . For example, a millrace is a sluice that channels water toward a water mill...

gates.

Alternating fields

During Emperor Wu's

Emperor Wu of Han

(r. 141–87 BCE) reign, the Grain Intendant Zhao Guo (趙過) invented the alternating fields system (daitianfa 代田法). For every mou

Chinese units of measurement

Chinese units of measurement are the customary and traditional units of measure used in China. In the People's Republic of China, the units were re-standardised during the late 20th century to make them approximate SI units. Many of the units were formerly based on the number 16 instead of 10...

of land—i.e. a thin but elongated strip of land measuring 1.38 m (4.5 ft) wide and 331 m (1085 ft) long, or an area of roughly 457 m² (0.113 acres) —three low-lying furrows

Ridge and furrow

Ridge and furrow is an archaeological pattern of ridges and troughs created by a system of ploughing used in Europe during the Middle Ages. The earliest examples date to the immediate post-Roman period and the system was used until the 17th century in some areas. Ridge and furrow topography is...

(quan 甽) that were each 0.23 m (0.7 ft) wide were sowed in straight lines with crop seed. While weeding in the summer, the loose soil of the ridges

Ridge and furrow

(long 壟) on either side of the furrows would gradually fall into the furrows, covering the sprouting crops and protecting them from wind and drought. Since the position of the furrows and ridges were reversed by the next year, this process was called the alternating fields system.
This system allowed crops to grow in straight lines from sowing to harvest, conserved moisture in the soil, and provided a stable annual yield for harvested crops. Zhao Guo first experimented with this system right outside the capital Chang'an

Chang'an

, and once it proved successful, he sent out instructions for it to every commandery administrator, who were then responsible for disseminating these to the heads of every county, district

District (China)

The term district, in the context of China, is used to refer to several unrelated political divisions in both ancient and modern China....

, and hamlet

Hamlet

The Tragical History of Hamlet, Prince of Denmark, or more simply Hamlet, is a tragedy by William Shakespeare, believed to have been written between 1599 and 1601...

in their commanderies. Sadao Nishijima speculates that the Imperial Counselor Sang Hongyang

Sang Hongyang

Sang Hongyang was a prominent official of the Former Han Dynasty, who served Emperor Wu of Han and his successor Emperor Zhao. He is most famed for his economic policies during the reign of Emperor Wu, the best known of which include the state monopolies over iron and salt - systems which would...

(d. 80 BCE) perhaps had a role in promoting this new system.

Rich families who owned oxen and large heavy moldboard iron plows greatly benefited from this new system. However, poorer farmers who did not own oxen resorted to using teams of men to move a single plow, which was exhausting work. The author Cui Shi (催寔) (d. 170 CE) wrote in his Simin yueling (四民月令) that by the Eastern Han Era (25–220 CE) an improved plow was invented which needed only one man to control it, two oxen to pull it, had three plowshares, a seed box for the drills, a tool which turned down the soil, and could sow roughly 45,730 m² (11.3 acres) of land in a single day.

Pit fields

During the reign of Emperor Cheng of Han

Emperor Cheng of Han

Emperor Cheng of Han was an emperor of the Chinese Han Dynasty ruling from 33 BC until 7 BC.Under Emperor Cheng, the Han dynasty continued its slide into disintegration while the Wang clan continued its slow grip on power and on governmental affairs as promoted by the previous emperor...

(r. 33–7 BCE), Fan Shengzhi wrote a manual (i.e. the Fan Shengzhi shu 氾勝之書) which described the pit field system (aotian 凹田). In this system, every mou of farmland was divided into 3,840 grids which each had a small pit that was dug 13.8 cm (5.5 in) deep and 13.8 cm (5.5 in) wide and had good quality manure

Manure

Manure is organic matter used as organic fertilizer in agriculture. Manures contribute to the fertility of the soil by adding organic matter and nutrients, such as nitrogen, that are trapped by bacteria in the soil...

mixed into the soil. Twenty seeds were sowed into each pit, which allegedly produced 0.6 L (20 oz

Fluid ounce

A fluid ounce is a unit of volume equal to about 28.4 mL in the imperial system or about 29.6 mL in the US system. The fluid ounce is distinct from the ounce, which measures mass...

) of harvested grain per pit, or roughly 2,000 L (67,630 oz) per mou. This system did not require oxen-driven plows or the most fertile land, since it could be employed even on sloping terrains where supplying water was difficult for other methods of farming. Although this farming method was favored by the poor, it did require intensive labor, thus only large families could maintain such a system.

Rice paddies

Han farmers in the Yangzi River region of southern China often maintained paddy field

Paddy field

A paddy field is a flooded parcel of arable land used for growing rice and other semiaquatic crops. Paddy fields are a typical feature of rice farming in east, south and southeast Asia. Paddies can be built into steep hillsides as terraces and adjacent to depressed or steeply sloped features such...

s for growing rice

Rice

Rice is the seed of the monocot plants Oryza sativa or Oryza glaberrima . As a cereal grain, it is the most important staple food for a large part of the world's human population, especially in East Asia, Southeast Asia, South Asia, the Middle East, and the West Indies...

. Every year, they would burn the weeds in the paddy field, drench it in water, sow rice by hand, and around harvest time cut the surviving weeds and drown them a second time. In this system, the field lays fallow

Crop rotation

Crop rotation is the practice of growing a series of dissimilar types of crops in the same area in sequential seasons.Crop rotation confers various benefits to the soil. A traditional element of crop rotation is the replenishment of nitrogen through the use of green manure in sequence with cereals...

for much of the year and thus did not remain very fertile. However, Han rice farmers to the north around the Huai River

Huai River

The Huai River is a major river in China. The Huai River is located about mid-way between the Yellow River and Yangtze River, the two largest rivers in China, and like them runs from west to east...

practiced the more advanced system of transplantation

Transplanting

For botanical organ transplant, see GraftingIn agriculture and gardening, transplanting or replanting is the technique of moving a plant from one location to another. Most often this takes the form of starting a plant from seed in optimal conditions, such as in a greenhouse or protected nursery...

. In this system, individual plants were given intensive care (perhaps in the same location as the paddy field), their offshoots separated so that more water could be conserved, and the field could be heavily fertilized since winter crops were grown while the rice seedlings were situated nearby in a plant nursery.

Literary sources and archaeological evidence

Evidence of Han-era mechanical engineering comes largely from the choice observational writings of sometimes disinterested Confucian scholars. Professional artisan-engineers (jiang 匠) did not leave behind detailed records of their work. Han scholars, who often had little or no expertise in mechanical engineering, sometimes provided insufficient information on the various technologies they described.

Nevertheless, some Han literary sources provide crucial information. As written by Yang Xiong in 15 BCE, the belt drive

Belt (mechanical)

A belt is a loop of flexible material used to link two or more rotating shafts mechanically. Belts may be used as a source of motion, to transmit power efficiently, or to track relative movement. Belts are looped over pulleys. In a two pulley system, the belt can either drive the pulleys in the...

was first used for a quilling

Quilling

Quilling or paper filigree is an art form that involves the use of strips of paper that are rolled, shaped, and glued together to create decorative designs. The paper is wound around a quill to create a basic coil shape...

device which wound silk fibers onto the bobbin

Bobbin

A bobbin is a spindle or cylinder, with or without flanges, on which wire, yarn, thread or film is wound. Bobbins are typically found in sewing machines, cameras, and within electronic equipment....

s of weaver shuttles. The invention of the belt drive was a crucial first step in the development of later technologies during the Song Dynasty

Technology of the Song Dynasty

, such as the chain drive

Chain drive

Chain drive is a way of transmitting mechanical power from one place to another. It is often used to convey power to the wheels of a vehicle, particularly bicycles and motorcycles...

and spinning wheel

Spinning wheel

A spinning wheel is a device for spinning thread or yarn from natural or synthetic fibers. Spinning wheels appeared in Asia, probably in the 11th century, and very gradually replaced hand spinning with spindle and distaff...

.

The inventions of the artisan-engineer Ding Huan (丁緩) are mentioned in the Miscellaneous Notes on the Western Capital. The official and poet Sima Xiangru

Sima Xiangru

Sima Xiangru, also known as Ssu-ma Hsiang-ju was a Chinese writer. He was a minor official of the Western Han Dynasty, but was better known for his poetic skills, jiu business, and controversial marriage to the widow Zhuo Wenjun after both eloped...

(179–117 BCE) once hinted in his writings that the Chinese used a censer

Censer

Censers are any type of vessels made for burning incense. These vessels vary greatly in size, form, and material of construction. They may consist of simple earthenware bowls or fire pots to intricately carved silver or gold vessels, small table top objects a few centimetres tall to as many as...

in the form of a gimbal

Gimbal

A gimbal is a pivoted support that allows the rotation of an object about a single axis. A set of two gimbals, one mounted on the other with pivot axes orthogonal, may be used to allow an object mounted on the innermost gimbal to remain immobile regardless of the motion of its support...

, a pivot support made of concentric rings which allow the central gimbal to rotate on an axis while remaining vertically positioned. However, the first explicit mention of the gimbal used as an incense burner occurred around 180 CE when the artisan Ding Huan created his 'Perfume Burner for use among Cushions' which allowed burning incense placed within the central gimbal to remain constantly level even when moved. Ding had other inventions as well. For the purpose of indoor air conditioning

Air conditioning

An air conditioner is a home appliance, system, or mechanism designed to dehumidify and extract heat from an area. The cooling is done using a simple refrigeration cycle...

, he set up a large manually operated rotary fan

Fan (mechanical)

A mechanical fan is a machine used to create flow within a fluid, typically a gas such as air.A fan consists of a rotating arrangement of vanes or blades which act on the air. Usually, it is contained within some form of housing or case. This may direct the airflow or increase safety by preventing...

which had rotating wheels that were 3 m (10 ft) in diameter. He also invented the zoetrope

Zoetrope

A zoetrope is a device that produces an illusion of action from a rapid succession of static pictures. The term zoetrope is from the Greek words "ζωή – zoe", "life" and τρόπος – tropos, "turn". It may be taken to mean "wheel of life"....

lamp, which he called the 'nine-storied hill-censer', since it was shaped as a hillside. When the cylindrical lamp was lit, the convection

Convection

Convection is the movement of molecules within fluids and rheids. It cannot take place in solids, since neither bulk current flows nor significant diffusion can take place in solids....

of rising hot air currents caused vanes placed on the top to spin, which in turn rotated painted paper figures of birds and other animals around the lamp.

When Emperor Gaozu of Han (r. 202 – 195 BCE) came upon the treasury of Qin Shi Huang

Qin Shi Huang

Qin Shi Huang , personal name Ying Zheng , was king of the Chinese State of Qin from 246 BC to 221 BC during the Warring States Period. He became the first emperor of a unified China in 221 BC...

(r. 221–210 BCE) at Xianyang

Xianyang

Xianyang is a former capital of China in Shaanxi province, on the Wei River, a few kilometers upstream from Xi'an. It has an area of...

following the downfall of the Qin Dynasty

Qin Dynasty

The Qin Dynasty was the first imperial dynasty of China, lasting from 221 to 207 BC. The Qin state derived its name from its heartland of Qin, in modern-day Shaanxi. The strength of the Qin state was greatly increased by the legalist reforms of Shang Yang in the 4th century BC, during the Warring...

(221–206 BCE), he found an entire miniature musical orchestra of puppet

Puppet

A puppet is an inanimate object or representational figure animated or manipulated by an entertainer, who is called a puppeteer. It is used in puppetry, a play or a presentation that is a very ancient form of theatre....

s 1 m (3 ft) tall who played mouth organs

Free reed aerophone

A free reed aerophone is a musical instrument where sound is produced as air flows past a vibrating reed in a frame. Air pressure is typically generated by breath or with a bellows.- Operation :...

if one pulled on ropes and blew into tubes to control them. Zhang Heng wrote in the 2nd century CE that people could be entertained by theatrical plays of artificial fish and dragons. Later, the inventor Ma Jun

Ma Jun

Ma Jun , style name Deheng , was a Chinese mechanical engineer and government official during the Three Kingdoms era of China...

(fl.

Floruit

Floruit , abbreviated fl. , is a Latin verb meaning "flourished", denoting the period of time during which something was active...

220–265 CE) invented a theater of moving mechanical puppets powered by the rotation of a hidden waterwheel.

From literary sources it is known that the collapsible umbrella was invented during Wang Mang's reign, although the simple parasol existed beforehand. This employed sliding levers and bendable joints that could be protracted and retracted.

Modern archaeology has led to the discovery of Han artwork portraying inventions which were otherwise absent in Han literary sources. This includes the crank handle

Crank (mechanism)

A crank is an arm attached at right angles to a rotating shaft by which reciprocating motion is imparted to or received from the shaft. It is used to change circular into reciprocating motion, or reciprocating into circular motion. The arm may be a bent portion of the shaft, or a separate arm...

. Han pottery tomb models of farmyards and gristmill

Gristmill

The terms gristmill or grist mill can refer either to a building in which grain is ground into flour, or to the grinding mechanism itself.- Early history :...

s possess the first known depictions of crank handles, which were used to operate the fans

Fan (mechanical)

of winnowing machines. The machine was used to separate chaff

Chaff

Chaff is the dry, scaly protective casings of the seeds of cereal grain, or similar fine, dry, scaly plant material such as scaly parts of flowers, or finely chopped straw...

from grain, but the Chinese of later dynasties also employed the crank handle for silk-reeling, hemp-spinning, flour-sifting, and drawing water from a well using the windlass

Windlass

The windlass is an apparatus for moving heavy weights. Typically, a windlass consists of a horizontal cylinder , which is rotated by the turn of a crank or belt...

. To measure distance traveled, the Han-era Chinese also created the odometer

Odometer

An odometer or odograph is an instrument that indicates distance traveled by a vehicle, such as a bicycle or automobile. The device may be electronic, mechanical, or a combination of the two. The word derives from the Greek words hodós and métron...

cart. This invention is depicted in Han artwork by the 2nd century CE, yet detailed written descriptions were not offered until the 3rd century CE. The wheels of this device rotated a set of gears which in turn forced mechanical figures to bang gongs and drums that alerted the travelers of the distance traveled (measured in li). From existing specimens found at archaeological sites, it is known that Han-era craftsmen made use of the sliding metal caliper

Caliper

A caliper is a device used to measure the distance between two opposing sides of an object. A caliper can be as simple as a compass with inward or outward-facing points...

to make minute measurements. Although Han-era calipers bear incised inscriptions of the exact day of the year they were manufactured, they are not mentioned in any Han literary sources.

Uses of the waterwheel and water clock

By the Han Dynasty, the Chinese developed various uses for the waterwheel. An improvement of the simple lever

Lever

In physics, a lever is a rigid object that is used with an appropriate fulcrum or pivot point to either multiply the mechanical force that can be applied to another object or resistance force , or multiply the distance and speed at which the opposite end of the rigid object travels.This leverage...

-and-fulcrum tilt hammer device operated by one's foot, the hydraulic-powered trip hammer

Trip hammer

A trip hammer, also known as a helve hammer, is a massive powered hammer used in:* agriculture to facilitate the labor of pounding, decorticating and polishing of grain;...

used for pounding, decorticating, and polishing grain was first mentioned in the Han dictionary

Chinese dictionary

Chinese dictionaries date back over two millennia to the Eastern Zhou Dynasty, which is a significantly longer lexicographical history than any other language. There are hundreds of dictionaries for Chinese, and this article will introduce some of the most important...

Ji jiu pian (急就篇) of 40 BCE. It was also mentioned in the Regional Speech
Fangyan
The Fāngyán , edited by Yang Xiong, was the first Chinese dictionary of dialectal terms. The full title is Yóuxuān shǐzhĕ juédài yǔ shì biéguó fāngyán "Local speeches of other countries in times immemorial explained by the Light-Carriage Messenger," which alludes to a Zhou Dynasty tradition of...

(Fangyan) dictionary written by Yang Xiong (53 BCE – 18 CE) in 15 BCE, the philosophical Xinlun 新論 written by Huan Tan

Huan Tan

Huan Tan 桓譚 was a Chinese philosopher of the Han Dynasty and short-lived interregnum of the Xin Dynasty . Huan's mode of philosophical thought belonged to an Old Text realist tradition supported by other contemporaries such as the naturalist and mechanistic philosopher Wang Chong Huan Tan 桓譚 (c....

(43 BCE – 28 CE) in 20 CE, the poetry of Ma Rong

Ma Rong

Ma Rong , courtesy name Jichang , was a commentator of the Han Dynasty. He was born in modern Xianyang, Shaanxi in former Fufeng county. He was known for his commentaries on the books on the Five Classics, and the first scholar known to have done this. He also developed the double column...

(79–166 CE), and the writings of Kong Rong

Kong Rong

Kong Rong was a politician, scholar, and minor warlord of the late Han Dynasty period of Chinese history. He was also a 20th generation descendant of Kong Qiu . As he was once the chancellor of Beihai Commandery , he was also known as Kong Beihai. He was defeated by Yuan Tan in 196 and escaped to...

(153–208 CE).

In his Balanced Discourse
Lunheng
The Lunheng is a wide-ranging Chinese classic text containing critical essays by Wang Chong on natural science, Chinese mythology, philosophy, and literature.-Title:...

(Lunheng), the philosopher Wang Chong

Wang Chong

(27–100 CE) was the first in China to describe the square-pallet chain pump used to lift water (and other substances). Although some models were operated manually by foot pedals, some chain pumps were powered by a horizontal waterwheel which rotated large toothed gears and a horizontal axis beam. Their primary use was for lifting water into irrigation ditches, but chain pumps were also used in public works

Public works

Public works are a broad category of projects, financed and constructed by the government, for recreational, employment, and health and safety uses in the greater community...

programs, such as when Zhang Rang

Zhang Rang

Zhang Rang was a eunuch of the late Han Dynasty, who served Emperor Ling of Han; he was also the leader of the Ten regular attendants , a group of court eunuchs who held great influence in the Han imperial court...

(d. 189 CE) had an engineer build several of them to lift water into pipes that provided the capital Luoyang

Luoyang

and its palaces

Chinese Palaces

Chinese Palaces are elaborate structures. There is a long history of imperial rule in China, and the palaces were the sites where the royal court resided, as well as many government bureaucrats and functionaries....

with clean water.

While acting as administrator of Nanyang

Nanyang, Henan

Nanyang is a prefecture-level city in the southwest of Henan province, People's Republic of China. The city with the largest administrative area in Henan, Nanyang borders Xinyang to the southeast, Zhumadian to the east, Pingdingshan to the northeast, Luoyang to the north, Sanmenxia to the...

in 31 CE, Du Shi

Du Shi

Du Shi 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 to operate bellows in metallurgy...

(d. 38 CE) invented a water-powered reciprocator

Reciprocating motion

Reciprocating motion, also called reciprocation, is a repetitive up-and-down or back-and-forth motion. It is found in a wide range of mechanisms, including reciprocating engines and pumps. The two opposite motions that comprise a single reciprocation cycle are called strokes...

which worked the bellows of the blast furnace and cupola furnace in smelting iron; before this invention, intensive manual labor was required to work the bellows.

Although the astronomical armillary sphere

Armillary sphere

(representing the celestial sphere

Celestial sphere

) existed in China since the 1st century BCE, the mathematician and court astronomer Zhang Heng

Zhang Heng

Zhang Heng was a Chinese astronomer, mathematician, inventor, geographer, cartographer, artist, poet, statesman, and literary scholar from Nanyang, Henan. He lived during the Eastern Han Dynasty of China. He was educated in the capital cities of Luoyang and Chang'an, and began his career as a...

(78–139 CE) provided it with motive power by using the constant pressure head

Pressure head

Pressure head is a term used in fluid mechanics to represent the internal energy of a fluid due to the pressure exerted on its container. It may also be called static pressure head or simply static head...

of an inflow water clock

Water clock

A water clock or clepsydra is any timepiece in which time is measured by the regulated flow of liquid into or out from a vessel where the amount is then measured.Water clocks, along with sundials, are likely to be the oldest time-measuring instruments, with the only exceptions...

to rotate a waterwheel that acted on a set of gear

Gear

A gear is a rotating machine part having cut teeth, or cogs, which mesh with another toothed part in order to transmit torque. Two or more gears working in tandem are called a transmission and can produce a mechanical advantage through a gear ratio and thus may be considered a simple machine....

s. Zhang Heng was also the first to address the problem of the falling pressure head in the inflow water clock (which gradually slowed the timekeeping

Timekeeper

A timekeeper is an instrument or person that measures the passage of time; in the case of the latter, often with the assistance of a clock or stopwatch...

) by setting up an additional tank between the reservoir and inflow vessel.

Seismometer

The Han court was responsible for the major efforts of disaster relief when natural disasters such as earthquake

Earthquake

An earthquake is the result of a sudden release of energy in the Earth's crust that creates seismic waves. The seismicity, seismism or seismic activity of an area refers to the frequency, type and size of earthquakes experienced over a period of time...

s devastated the lives of commoners. To better prepare for calamities, Zhang Heng invented a seismometer

Seismometer

Seismometers are instruments that measure motions of the ground, including those of seismic waves generated by earthquakes, volcanic eruptions, and other seismic sources...

in 132 CE which provided instant alert to authorities in the capital Luoyang that an earthquake had occurred in a location indicated by a specific cardinal or ordinal direction

Cardinal direction

The four cardinal directions or cardinal points are the directions of north, east, south, and west, commonly denoted by their initials: N, E, S, W. East and west are at right angles to north and south, with east being in the direction of rotation and west being directly opposite. Intermediate...

. Although no tremors could be felt in the capital when Zhang told the court that an earthquake had just occurred in the northwest, a message came soon afterwards that an earthquake had indeed struck 400 km (248 mi) to 500 km (310 mi) northwest of Luoyang (in what is now modern Gansu

Gansu

). Zhang called his device the 'instrument for measuring the seasonal winds and the movements of the Earth' (Houfeng didong yi 候风地动仪), so-named because he and others thought that earthquakes were most likely caused by the enormous compression of trapped air.

As described in the Book of the Later Han, the frame of the seismometer was a domed bronze vessel in the shape of a wine jar

Wine in China

Wine in China refers to grape wines that are produced in China. Grape wine has a long history in China, along with other Chinese alcoholic beverages....

, although it was 1.8 m (6 ft) in diameter and decorated with scenes of mountains and animals. The trigger mechanism was an inverted pendulum

Inverted pendulum

An inverted pendulum is a pendulum which has its mass above its pivot point. It is often implemented with the pivot point mounted on a cart that can move horizontally and may be called a cart and pole...

(which the Book of the Later Han calls the "central column") that, if disturbed by the ground tremors of earthquakes located near or far away, would swing and strike one of eight mobile arms (representing the eight directions), each with a crank and catch mechanism. The crank and a right angle lever would raise one of eight metal dragon heads located on the exterior, dislodging a metal ball from its mouth that dropped into the mouth of one of eight metal toads below arranged like the points on a compass rose

Compass rose

A compass rose, sometimes called a windrose, is a figure on a compass, map, nautical chart or monument used to display the orientation of the cardinal directions — North, East, South and West - and their intermediate points. It is also the term for the graduated markings found on the traditional...

, thus indicating the direction of the earthquake. The Book of the Later Han states that when the ball fell into any one of eight toad mouths, it produced a loud noise which gained the attention of those observing the device. While Wang Zhenduo (王振铎) accepted the idea that Zhang's seismometer had cranks and levers which were disturbed by the inverted pendulum, his contemporary Akitsune Imamura

Akitsune Imamura

was a Japanese seismologist. Born in a poor family, he nonetheless managed to study at the Imperial University of Tokyo. In 1899, in anticipation of the later theory of plate tectonics, he argued that the tsunami that struck the Sanriku coast of Honshū island in 1896 had been triggered by...

(1870–1948) argued that the inverted pendulum could have had a pin at the top which, upon moving by force of the ground vibrations, would enter one of eight slots and expel the ball by pushing a slider. Since the Book of the Later Han states that the other seven dragon heads would not subsequently release the balls lodged up into their jaws after the first one had dropped, Imamura asserted that the pin of the pendulum would have been locked into the slot it had entered and thus immobilized the instrument until it was reset.

Mathematical treatises

One of the earliest surviving mathematical treatises of ancient China is the Book on Numbers and Computation (Suan shu shu), part of the Zhangjiashan Han bamboo texts

Zhangjiashan Han bamboo texts

The Zhangjiashan Han bamboo texts are ancient Han Dynasty Chinese written works dated 196–186 BCE. They were discovered in 1983 by archaeologists excavating tomb no. 247 at Mount Zhangjia of Jiangling County, Hubei Province . The tomb was built for an early Western Han era official who had...

dated 202 to 186 BCE and found in Jiangling County, Hubei

Hubei

' Hupeh) is a province in Central China. The name of the province means "north of the lake", referring to its position north of Lake Dongting...

. Another mathematical text compiled during the Han was The Arithmetical Classic of the Gnomon and the Circular Paths of Heaven (Zhoubi suanjing), dated no earlier than the 1st century BCE (from perhaps multiple authors) and contained materials similar to those described by Yang Xiong in 15 BCE, yet the zhoubi school of mathematics was not explicitly mentioned until Cai Yong

Cai Yong

Cai Yong was a Chinese scholar of the Eastern Han Dynasty. He was well-versed in calligraphy, music, mathematics and astronomy. One of his daughters is the famous Cai Wenji.-Early life:...

's (132–192 CE) commentary of 180 CE. A preface was added to the text by Zhao Shuang 趙爽 in the 3rd century CE. There was also the Nine Chapters on the Mathematical Art (Jiuzhang Suanshu); its full title was found on two bronze standard measurers dated 179 CE (with speculation that its material existed in earlier books under different titles) and was provided with detailed commentary by Liu Hui

Liu Hui

Liu Hui was a mathematician of the state of Cao Wei during the Three Kingdoms period of Chinese history. In 263, he edited and published a book with solutions to mathematical problems presented in the famous Chinese book of mathematic known as The Nine Chapters on the Mathematical Art .He was a...

(fl. 3rd century CE) in 263 CE.

Innovations in the treatises

The Suan shu shu presents basic mathematics problems and solutions. It was most likely a handbook for day-to-day business transactions or affairs of government administration. It contains problems and solutions for field measurements of area

Area

Area is a quantity that expresses the extent of a two-dimensional surface or shape in the plane. Area can be understood as the amount of material with a given thickness that would be necessary to fashion a model of the shape, or the amount of paint necessary to cover the surface with a single coat...

, proportional exchange rate

Exchange rate

In finance, an exchange rate between two currencies is the rate at which one currency will be exchanged for another. It is also regarded as the value of one country’s currency in terms of another currency...

s for agricultural millet

Millet

The millets are a group of small-seeded species of cereal crops or grains, widely grown around the world for food and fodder. They do not form a taxonomic group, but rather a functional or agronomic one. Their essential similarities are that they are small-seeded grasses grown in difficult...

and rice

Rice

, distribution by proportion

Proportionality (mathematics)

In mathematics, two variable quantities are proportional if one of them is always the product of the other and a constant quantity, called the coefficient of proportionality or proportionality constant. In other words, are proportional if the ratio \tfrac yx is constant. We also say that one...

, short width division, and excess and deficiency. Some of the problems found in the Suan shu shu appear in the later text Jiuzhang suanshu; in five cases, the titles are exact matches. However, unlike the Jiuzhang suanshu, the Suan shu shu does not deal with problems involving right-angle triangles, square root

Square root

In mathematics, a square root of a number x is a number r such that r2 = x, or, in other words, a number r whose square is x...

s, cube roots, and matrix methods

Matrix (mathematics)

In mathematics, a matrix is a rectangular array of numbers, symbols, or expressions. The individual items in a matrix are called its elements or entries. An example of a matrix with six elements isMatrices of the same size can be added or subtracted element by element...

, which demonstrates the significant advancements made in Chinese mathematics between the writings of these two texts.

The Zhoubi suanjing, written in dialogue form and with regularly presented problems, is concerned with the application of mathematics to astronomy

Astronomy

Astronomy is a natural science that deals with the study of celestial objects and phenomena that originate outside the atmosphere of Earth...

. In one problem which sought to determine the height of the Sun

Sun

The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...

from the Earth

Earth

Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...

and the diameter

Diameter

In geometry, a diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints are on the circle. The diameters are the longest chords of the circle...

of the Sun, Chen Zi (陳子) instructs Rong Fang (榮方) to wait until the shadow cast by the 8 chi tall gnomon

Gnomon

The gnomon is the part of a sundial that casts the shadow. Gnomon is an ancient Greek word meaning "indicator", "one who discerns," or "that which reveals."It has come to be used for a variety of purposes in mathematics and other fields....

is 6 chi
Chinese units of measurement
Chinese units of measurement are the customary and traditional units of measure used in China. In the People's Republic of China, the units were re-standardised during the late 20th century to make them approximate SI units. Many of the units were formerly based on the number 16 instead of 10...

(one chi during the Han was 33 cm), so that a 3-4-5 right-angle triangle can be constructed where the base is 60,000 li

Li (unit)

The li is a traditional Chinese unit of distance, which has varied considerably over time but now has a standardized length of 500 meters or half a kilometer...

(one li during the Han was the equivalent of 415 m or 1362 ft), the hypotenuse

Hypotenuse

In geometry, a hypotenuse is the longest side of a right-angled triangle, the side opposite the right angle. The length of the hypotenuse of a right triangle can be found using the Pythagorean theorem, which states that the square of the length of the hypotenuse equals the sum of the squares of the...

leading towards the sun is 100,000 li, and the height of the sun is 80,000 li. Like the Jiuzhang suanshu, the Zhoubi suanjing also gives mathematical proof

Mathematical proof

In mathematics, a proof is a convincing demonstration that some mathematical statement is necessarily true. Proofs are obtained from deductive reasoning, rather than from inductive or empirical arguments. That is, a proof must demonstrate that a statement is true in all cases, without a single...

for the "Gougu Theorem" (勾股定理; i.e. where c is the length of the hypotenuse and a and b are the lengths of the other two sides, respectively, a² + b² = c²), which is known as the Pythagorean theorem

Pythagorean theorem

In mathematics, the Pythagorean theorem or Pythagoras' theorem is a relation in Euclidean geometry among the three sides of a right triangle...

in the West after the Greek mathematician Pythagoras

Pythagoras

Pythagoras of Samos was an Ionian Greek philosopher, mathematician, and founder of the religious movement called Pythagoreanism. Most of the information about Pythagoras was written down centuries after he lived, so very little reliable information is known about him...

(fl. 6th century BCE).

The Jiuzhang suanshu was perhaps the most groundbreaking of the three surviving Han treatises. It is the first known book to feature negative numbers, along with the Bakhshali manuscript

Bakhshali Manuscript

The Bakhshali Manuscript is an Ancient Indian mathematical manuscript written on birch bark which was found near the village of Bakhshali in 1881 in what was then the North-West Frontier Province of British India...

(200 CE? – 600 CE?) of India

India

India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...

and the book of the Greek

Greek mathematics

Greek mathematics, as that term is used in this article, is the mathematics written in Greek, developed from the 7th century BC to the 4th century AD around the Eastern shores of the Mediterranean. Greek mathematicians lived in cities spread over the entire Eastern Mediterranean, from Italy to...

mathematician Diophantus

Diophantus

Diophantus of Alexandria , sometimes called "the father of algebra", was an Alexandrian Greek mathematician and the author of a series of books called Arithmetica. These texts deal with solving algebraic equations, many of which are now lost...

(fl. 3rd century) written in about 275 CE. Negative numbers appeared as black counting rods

Counting rods

Counting rods are small bars, typically 3–14 cm long, used by mathematicians for calculation in China, Japan, Korea, and Vietnam. They are placed either horizontally or vertically to represent any number and any fraction....

, while positive numbers appeared as red counting rods

Counting rods

. Although the decimal

Decimal

The decimal numeral system has ten as its base. It is the numerical base most widely used by modern civilizations....

system existed in China since the Shang Dynasty

Shang Dynasty

(c. 1600 – c. 1050 BCE), the earliest evidence of a decimal fraction

Fraction (mathematics)

A fraction represents a part of a whole or, more generally, any number of equal parts. When spoken in everyday English, we specify how many parts of a certain size there are, for example, one-half, five-eighths and three-quarters.A common or "vulgar" fraction, such as 1/2, 5/8, 3/4, etc., consists...

(i.e. the denominator is a power

Exponentiation

Exponentiation is a mathematical operation, written as an, involving two numbers, the base a and the exponent n...

of ten) is an inscription on a standard volume-measuring vessel dated 5 CE and used by the mathematician and astronomer Liu Xin

Liu Xin

Liu Xin , later changed name to Liu Xiu , courtesy name Zijun , was a Chinese astronomer, historian, and editor during the Xin Dynasty . He was the son of Confucian scholar Liu Xiang and an associate of other prominent thinkers such as the philosopher Huan Tan...

(46 BCE – 23 CE). Yet the first book to feature decimal fractions was the Jiuzhang suanshu, as a means to solve equation

Equation

An equation is a mathematical statement that asserts the equality of two expressions. In modern notation, this is written by placing the expressions on either side of an equals sign , for examplex + 3 = 5\,asserts that x+3 is equal to 5...

s and represent measurements. Gaussian elimination

Gaussian elimination

, an algorithm

Algorithm

In mathematics and computer science, an algorithm is an effective method expressed as a finite list of well-defined instructions for calculating a function. Algorithms are used for calculation, data processing, and automated reasoning...

used to solve linear equations, was known as the Array Rule in the Jiuzhang suanshu. While the book used continued fractions to find the roots of equations, Liu Hui built on this idea in the 3rd century when he increased the decimals to find the cube root of 1,860,867 (yielding the answer 123), the same method used in the Horner scheme

Horner scheme

named after William George Horner

William George Horner

William George Horner was a British mathematician and schoolmaster. The invention of the zoetrope, in 1834 and under a different name , has been attributed to him.-Life:...

(1786–1837).

Approximations of pi

For centuries, the Chinese had simply approximated the value of pi

' is a mathematical constant that is the ratio of any circle's circumference to its diameter. is approximately equal to 3.14. Many formulae in mathematics, science, and engineering involve , which makes it one of the most important mathematical constants...

as 3, until Liu Xin approximated it at 3.154 sometime between 1–5 CE, although the method he used to reach this value is unknown to historians. Standard measuring vessels dating to the reign of Wang Mang

Wang Mang

(9–23 CE) also showed approximations for pi at 3.1590, 3.1497, and 3.167. Zhang Heng is the next known Han mathematician to have made an approximation for pi. Han mathematicians understood that the area of a square versus the area of its inscribed circle had a ratio

Ratio

In mathematics, a ratio is a relationship between two numbers of the same kind , usually expressed as "a to b" or a:b, sometimes expressed arithmetically as a dimensionless quotient of the two which explicitly indicates how many times the first number contains the second In mathematics, a ratio is...

of 4:3, and also understood that the volume of a cube and the volume of its inscribed sphere would be 4²:3². With D as diameter

Diameter

and V as volume, D³:V = 16:9 or V=⁹⁄₁₆D³, a formula Zhang found fault with since he realized the value for diameter was inaccurate, the discrepancy being the value taken for the ratio. To fix this, Zhang added ¹⁄₁₆D³ to the formula, thus V = ⁹⁄₁₆D³ + ¹⁄₁₆D³ = ⁵⁄₈D³. Since he found the ratio of the volume of the cube to the inscribed sphere at 8:5, the ratio of the area of a square to the inscribed circle is √8:√5. With this formula, Zhang was able to approximate pi as the square root

Square root

In mathematics, a square root of a number x is a number r such that r2 = x, or, in other words, a number r whose square is x...

of 10, or 3.162. After the Han, Liu Hui approximated pi as 3.14159, while the mathematician Zu Chongzhi

Zu Chongzhi

Zu Chongzhi , courtesy name Wenyuan , was a prominent Chinese mathematician and astronomer during the Liu Song and Southern Qi Dynasties.-Life and works:...

(429–500 CE) approximated pi at 3.141592 (or ³⁵⁵⁄₁₁₃), the most accurate approximation the ancient Chinese would achieve.

Musical tuning and theory

Mathematics were also used in musical tuning

Musical tuning

In music, there are two common meanings for tuning:* Tuning practice, the act of tuning an instrument or voice.* Tuning systems, the various systems of pitches used to tune an instrument, and their theoretical bases.-Tuning practice:...

and music theory

Music theory

Music theory is the study of how music works. It examines the language and notation of music. It seeks to identify patterns and structures in composers' techniques across or within genres, styles, or historical periods...

. The 2nd-century-BCE Huainanzi
Huainanzi
The Huáinánzǐ is a 2nd century BCE Chinese philosophical classic from the Han dynasty that blends Daoist, Confucianist, and Legalist concepts, including theories such as Yin-Yang and the Five Phases. It was written under the patronage of Liu An, Prince of Huainan, a legendarily prodigious author...

, compiled by eight scholars

Eight Immortals of Huainan

The Eight Immortals of Huainan , also known as the Eight Gentlemen , were the eight scholars under the patronage of Liu An , the prince of Huainan during the Western Han Dynasty. They are not deified in any religions and the xian "immortal" is used metaphorically to describe their talent...

under the patronage of King Liu An

Liu An

Líu Ān was a Chinese prince and advisor to his nephew, Emperor Wu of Han of the Han Dynasty in China and the legendary inventor of t'ai chi...

(179–122 BCE), outlined the use of twelve tones

Chromatic scale

The chromatic scale is a musical scale with twelve pitches, each a semitone apart. On a modern piano or other equal-tempered instrument, all the half steps are the same size...

on a musical scale

Musical scale

In music, a scale is a sequence of musical notes in ascending and descending order. Most commonly, especially in the context of the common practice period, the notes of a scale will belong to a single key, thus providing material for or being used to conveniently represent part or all of a musical...

. Jing Fang

Jing Fang

Jing Fang , born Li Fang , courtesy name Junming , was a Chinese music theorist, mathematician and astrologer. Born in present-day Puyang, Henan during the Han Dynasty , he was the first to notice how closely a succession of 53 just fifths approximates 31 octaves...

(78–37 BCE), a mathematician and music theorist, expanded these to create a scale of 60 tones. While doing so, Jing Fang realized that 53 just fifths is approximate to 31 octave

Octave

In music, an octave is the interval between one musical pitch and another with half or double its frequency. The octave relationship is a natural phenomenon that has been referred to as the "basic miracle of music", the use of which is "common in most musical systems"...

s. By calculating the difference at ¹⁷⁷¹⁴⁷⁄₁₇₆₇₇₆, Jing reached the same value of 53 equal temperament

53 equal temperament

In music, 53 equal temperament, called 53-TET, 53-EDO, or 53-ET, is the tempered scale derived by dividing the octave into 53 equal steps . Each step represents a frequency ratio of 21/53, or 22.6415 cents , an interval sometimes called the Holdrian comma.- History :Theoretical interest in this...

duly discovered by the German mathematician Nicholas Mercator

Nicholas Mercator

Nicholas Mercator , also known by his Germanic name Kauffmann, was a 17th-century mathematician....

(1620–1687) (i.e. 3⁵³/2⁸⁴, known as Mercator's Comma). Later, the prince Zhu Zaiyu

Zhu Zaiyu

Zhu Zaiyu , a prince of the Ming dynasty of China. In 1584 Prince Zhu innovatively described the equal temperament via accurate mathematical calculation...

(1536–1611 CE) in Ming China

Ming Dynasty

The Ming Dynasty, also Empire of the Great Ming, was the ruling dynasty of China from 1368 to 1644, following the collapse of the Mongol-led Yuan Dynasty. The Ming, "one of the greatest eras of orderly government and social stability in human history", was the last dynasty in China ruled by ethnic...

and Simon Stevin

Simon Stevin

Simon Stevin was a Flemish mathematician and military engineer. He was active in a great many areas of science and engineering, both theoretical and practical...

(1548–1620 CE) of the Flemish Region

Flemish Region

The Flemish Region is one of the three official regions of the Kingdom of Belgium—alongside the Walloon Region and the Brussels-Capital Region. Colloquially, it is usually simply referred to as Flanders, of which it is the institutional iteration within the context of the Belgian political system...

in Europe

Europe

Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

would simultaneously (but separately) discover the mathematical formula for equal temperament.

Astronomical observations

The ancient Chinese made meticulous observations of heavenly bodies and phenomena since observations of the cosmos were used for astrology

Astrology

Astrology consists of a number of belief systems which hold that there is a relationship between astronomical phenomena and events in the human world...

and prognostication. The astronomer Gan De

Gan De

Gan De was a Chinese astronomer/astrologer born in the State of Qi also known as the Lord Gan . Along with Shi Shen, he is believed to be the first in history known by name to compile a star catalogue, preceded by the anonymous authors of the early Babylonian star catalogues and followed by the...

(fl. 4th century BCE) from the State of Qi

Qi (state)

Qi was a powerful state during the Spring and Autumn Period and Period of the Warring States in ancient China. Its capital was Linzi, now part of the modern day city of Zibo in Shandong Province....

was the first in history to acknowledge sunspot

Sunspot

Sunspots are temporary phenomena on the photosphere of the Sun that appear visibly as dark spots compared to surrounding regions. They are caused by intense magnetic activity, which inhibits convection by an effect comparable to the eddy current brake, forming areas of reduced surface temperature....

s as genuine solar phenomena (and not obstructing natural satellite

Natural satellite

A natural satellite or moon is a celestial body that orbits a planet or smaller body, which is called its primary. The two terms are used synonymously for non-artificial satellites of planets, of dwarf planets, and of minor planets....

s as thought in the West after Einhard

Einhard

Einhard was a Frankish scholar and courtier. Einhard was a dedicated servant of Charlemagne and his son Louis the Pious; his main work is a biography of Charlemagne, the Vita Karoli Magni, "one of the most precious literary bequests of the early Middle Ages."-Public life:Einhard was from the eastern...

's observation in 807 CE), while the first precisely dated sunspot observation in China occurred on May 10, 28 BCE during the reign of Emperor Cheng of Han

Emperor Cheng of Han

(r. 33–7 BCE). Among the Mawangdui Silk Texts

Mawangdui Silk Texts

dated no later than 168 BCE (when they were sealed in a tomb at Mawangdui, Changsha, Hunan

Hunan

' is a province of South-Central China, located to the south of the middle reaches of the Yangtze River and south of Lake Dongting...

province), the Miscellaneous Readings of Cosmic Patterns and Pneuma Images (Tianwen qixiang zazhan 天文氣象雜占) manuscript illustrates in writings and ink drawings roughly three-hundred different climatic and astronomical features including clouds, mirage

Mirage

A mirage is a naturally occurring optical phenomenon in which light rays are bent to produce a displaced image of distant objects or the sky. The word comes to English via the French mirage, from the Latin mirare, meaning "to look at, to wonder at"...

s, rainbow

Rainbow

A rainbow is an optical and meteorological phenomenon that causes a spectrum of light to appear in the sky when the Sun shines on to droplets of moisture in the Earth's atmosphere. It takes the form of a multicoloured arc...

s, star

Star

A star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...

s, constellation

Constellation

In modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky....

s, and comet

Comet

A comet is an icy small Solar System body that, when close enough to the Sun, displays a visible coma and sometimes also a tail. These phenomena are both due to the effects of solar radiation and the solar wind upon the nucleus of the comet...

s. Another silk text from the same site reports the times and locations of the rising and setting of planets in the night sky from the years 246–177 BCE.

The Han-era Chinese noted the passage of the same comet seen in Persia for the birth of Mithridates II of Parthia

Mithridates II of Parthia

Mithridates II the Great was king of Parthian Empire from 123 to 88 BC. His name invokes the protection of Mithra. He adopted the title Epiphanes, "god manifest" and introduced new designs on his extensive coinage....

in 135 BCE, the same comet the Romans

Ancient Rome

Ancient Rome was a thriving civilization that grew on the Italian Peninsula as early as the 8th century BC. Located along the Mediterranean Sea and centered on the city of Rome, it expanded to one of the largest empires in the ancient world....

observed close to the assassination of Julius Caesar

Assassination of Julius Caesar

The assassination of Julius Caesar was the result of a conspiracy by approximately forty Roman senators who called themselves Liberators. Led by Gaius Cassius Longinus and Marcus Junius Brutus, they stabbed Julius Caesar to death in the Theatre of Pompey on the Ides of March 44 BC...

in 44 BCE, Halley's comet in 12 BCE, the same comet noted by Roman historian Cassius Dio (c. 155 – c. 229 CE) for 13 CE, and (what is now known to have been) a supernova

Supernova

A supernova is a stellar explosion that is more energetic than a nova. It is pronounced with the plural supernovae or supernovas. Supernovae are extremely luminous and cause a burst of radiation that often briefly outshines an entire galaxy, before fading from view over several weeks or months...

in 185 CE. For various comets discussed in the Han-era history books Records of the Grand Historian
Records of the Grand Historian
The Records of the Grand Historian, also known in English by the Chinese name Shiji , written from 109 BC to 91 BC, was the Magnum opus of Sima Qian, in which he recounted Chinese history from the time of the Yellow Emperor until his own time...

and Book of Han
Book of Han
The Book of Han, Hanshu or History of the Former Han Dynasty |Fan Ye]] . Various scholars have estimated that the earliest material covered in the book dates back to between 206 and 202 BCE...

, details are given for their position in the sky and direction they were moving, the length of time they were visible, their color, and their size.

The Han-era Chinese also made star catalogue

Star catalogue

A star catalogue, or star catalog, is an astronomical catalogue that lists stars. In astronomy, many stars are referred to simply by catalogue numbers. There are a great many different star catalogues which have been produced for different purposes over the years, and this article covers only some...

s, such as historian Sima Qian

Sima Qian

Sima Qian was a Prefect of the Grand Scribes of the Han Dynasty. He is regarded as the father of Chinese historiography for his highly praised work, Records of the Grand Historian , a "Jizhuanti"-style general history of China, covering more than two thousand years from the Yellow Emperor to...

's (145–86 BCE) A Monograph on Celestial Officials (Tianguanshu 天官書) and Zhang Heng's 2nd-century-CE star catalogue which featured roughly 2,500 stars and 124 constellations. To create a three dimensional representation of such observations, Astronomer Geng Shouchang (耿壽昌) provided his armillary sphere

Armillary sphere

with an equatorial ring

Equatorial coordinate system

The equatorial coordinate system is a widely-used method of mapping celestial objects. It functions by projecting the Earth's geographic poles and equator onto the celestial sphere. The projection of the Earth's equator onto the celestial sphere is called the celestial equator...

in 52 BCE. By 84 CE the elliptical ring was added to the armillary sphere, while Zhang Heng's model of 125 CE added the celestial horizon

Celestial horizon

The celestial horizon, also called the rational horizon, is a great circle parallel to the horizon, in which a plane at right angles to Zenith and Nadir lines are passing through the centre of the earth and intersects the celestial sphere, the center of which is the center of the Earth....

ring and meridian

Meridian (astronomy)

This article is about the astronomical concept. For other uses of the word, see Meridian.In the sky, a meridian is an imaginary great circle on the celestial sphere. It passes through the north point on the horizon, through the celestial pole, up to the zenith, through the south point on the...

ring.

Han calendars

The Han Chinese used astronomical studies mainly to construct and revise their calendar

Calendar

A calendar is a system of organizing days for social, religious, commercial, or administrative purposes. This is done by giving names to periods of time, typically days, weeks, months, and years. The name given to each day is known as a date. Periods in a calendar are usually, though not...

. In contrast to the Julian calendar

Julian calendar

The Julian calendar began in 45 BC as a reform of the Roman calendar by Julius Caesar. It was chosen after consultation with the astronomer Sosigenes of Alexandria and was probably designed to approximate the tropical year .The Julian calendar has a regular year of 365 days divided into 12 months...

(46 BCE) and Gregorian calendar

Gregorian calendar

The Gregorian calendar, also known as the Western calendar, or Christian calendar, is the internationally accepted civil calendar. It was introduced by Pope Gregory XIII, after whom the calendar was named, by a decree signed on 24 February 1582, a papal bull known by its opening words Inter...

(1582 CE) of the West

Western world

The Western world, also known as the West and the Occident , is a term referring to the countries of Western Europe , the countries of the Americas, as well all countries of Northern and Central Europe, Australia and New Zealand...

(but like the Hellenic calendars of Classical Greece

Classical Greece

Classical Greece was a 200 year period in Greek culture lasting from the 5th through 4th centuries BC. This classical period had a powerful influence on the Roman Empire and greatly influenced the foundation of Western civilizations. Much of modern Western politics, artistic thought, such as...

), the Chinese calendar

Chinese calendar

is a lunisolar calendar

Lunisolar calendar

, meaning that it uses the precise movements of the Sun

Sun

The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...

and Moon

Moon

The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...

as time-markers throughout the year. In the 5th century BCE during the Spring and Autumn Period, the Chinese established the Sifen calendar (古四分历), which measured the tropical year

Tropical year

A tropical year , for general purposes, is the length of time that the Sun takes to return to the same position in the cycle of seasons, as seen from Earth; for example, the time from vernal equinox to vernal equinox, or from summer solstice to summer solstice...

at 365¹⁄₄ days (like the Julian calendar of Rome). Emperor Wu replaced this with the new Taichu calendar (太初历) in 104 BCE which measured the tropical year at 365³⁸⁵⁄₁₅₃₉ days and the lunar month

Lunar month

In lunar calendars, a lunar month is the time between two identical syzygies . There are many variations. In Middle-Eastern and European traditions, the month starts when the young crescent moon becomes first visible at evening after conjunction with the Sun one or two days before that evening...

at 29⁴³⁄₈₁ days. Since the Taichu calendar had become inaccurate over two centuries, Emperor Zhang of Han

Emperor Zhang of Han

Emperor Zhang of Han, ch. 漢章帝, py. hàn zhāng dì, wg. Han Chang-ti, was an emperor of the Chinese Han Dynasty from 75 to 88. He was the third emperor of the Chinese Eastern Han Dynasty....

(r. 75–88 CE) halted its use and revived use of the Sifen calendar. Later, astronomer Guo Shoujing

Guo Shoujing

Guo Shoujing , courtesy name Ruosi , was a Chinese astronomer, engineer, and mathematician born in Xingtai, Hebei who lived during the Yuan Dynasty...

(1233–1316 CE) would set the tropical year at 365.2425 days for his Shoushi calendar (授時曆), the same value used in the Gregorian calendar. Besides the use of the calendar for regulating agricultural practices throughout the seasons, it was also used to mark important dates in the sexagenary cycle

Sexagenary cycle

The Chinese sexagenary cycle , also known as the Stems-and-Branches , is a cycle of sixty terms used for recording days or years. It appears, as a means of recording days, in the first Chinese written texts, the Shang dynasty oracle bones from the late second millennium BC. Its use to record years...

—constructed by celestial stems (gan 干) and earthly branches

Earthly Branches

The Earthly Branches provide one Chinese system for reckoning time.This system was built from observations of the orbit of Jupiter. Chinese astronomers divided the celestial circle into 12 sections to follow the orbit of Suìxīng . Astronomers rounded the orbit of Suixing to 12 years...

(zhi 支), each of the latter associated with an animal of the Chinese zodiac

Chinese astrology

Chinese astrology is based on the traditional astronomy and calendars. The development of Chinese astrology is tied to that of astronomy, which came to flourish during the Han Dynasty ....

Astronomical theory

Zhao Shaung's 3rd-century commentary in the Zhoubi suanjing describes two astronomical theories: in one, the heavens are shaped as a hemi-spherical dome extending over the earth, while the other compares the earth to the central yolk of an egg

Egg yolk

An egg yolk is a part of an egg which feeds the developing embryo. The egg yolk is suspended in the egg white by one or two spiral bands of tissue called the chalazae...

, where the heavens are shaped as a celestial sphere

Celestial sphere

around the earth. The latter astronomical theory was mentioned by Yang Xiong in his Model Sayings (Fayan 法言) and expounded on by Zhang Heng in his Spiritual Constitution of the Universe (Lingxian 靈憲) of 120 CE. Thus, the Han-era Chinese believed in a geocentric model

Geocentric model

In astronomy, the geocentric model , is the superseded theory that the Earth is the center of the universe, and that all other objects orbit around it. This geocentric model served as the predominant cosmological system in many ancient civilizations such as ancient Greece...

for the immediate solar system

Solar System

The Solar System consists of the Sun and the astronomical objects gravitationally bound in orbit around it, all of which formed from the collapse of a giant molecular cloud approximately 4.6 billion years ago. The vast majority of the system's mass is in the Sun...

and greater universe, as opposed to a heliocentric model

Heliocentrism

Heliocentrism, or heliocentricism, is the astronomical model in which the Earth and planets revolve around a stationary Sun at the center of the universe. The word comes from the Greek . Historically, heliocentrism was opposed to geocentrism, which placed the Earth at the center...

The Han-era Chinese discussed the illumination and shapes of heavenly bodies: were they flat and circular, or were they rounded and spherical? Jing Fang wrote in the 1st century BCE that Han astronomers believed the Sun, Moon, and planets were spherical like balls or crossbow

Crossbow

A crossbow is a weapon consisting of a bow mounted on a stock that shoots projectiles, often called bolts or quarrels. The medieval crossbow was called by many names, most of which derived from the word ballista, a torsion engine resembling a crossbow in appearance.Historically, crossbows played a...

bullets. He also wrote that the Moon and planets produce no light of their own, are viewable to people on Earth only because they are illuminated by the Sun, and those parts not illuminated by the Sun would be dark on the other side. For this, Jing compared the Moon to a mirror illuminating light. In the 2nd century CE, Zhang Heng drew a similar comparison to Jing's by stating that the Sun is like fire and the Moon and planets are like water, since fire produces light and water reflects it. He also repeated Jing's comment that the side of the moon not illuminated by the Sun was left in darkness. However, Zhang noted that sunlight

Sunlight

Sunlight, in the broad sense, is the total frequency spectrum of electromagnetic radiation given off by the Sun. On Earth, sunlight is filtered through the Earth's atmosphere, and solar radiation is obvious as daylight when the Sun is above the horizon.When the direct solar radiation is not blocked...

did not always reach the Moon since the Earth obstructs the rays during a lunar eclipse

Lunar eclipse

A lunar eclipse occurs when the Moon passes behind the Earth so that the Earth blocks the Sun's rays from striking the Moon. This can occur only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, a lunar eclipse can only occur the night of a...

. He also noted that a solar eclipse

Solar eclipse

As seen from the Earth, a solar eclipse occurs when the Moon passes between the Sun and the Earth, and the Moon fully or partially blocks the Sun as viewed from a location on Earth. This can happen only during a new moon, when the Sun and the Moon are in conjunction as seen from Earth. At least...

occurred when the Moon and Sun crossed paths to block sunlight from reaching earth.

In his Balanced Discourse
Lunheng
The Lunheng is a wide-ranging Chinese classic text containing critical essays by Wang Chong on natural science, Chinese mythology, philosophy, and literature.-Title:...

(Lunheng), Wang Chong

Wang Chong

(27–100 CE) wrote that some Han thinkers believed that rain fell from the Heavens (i.e. where the stars were located). Wang argued that, although rain fell from above, this common theory was false. He agreed with another theory that stated clouds were formed by the evaporation

Evaporation

Evaporation is a type of vaporization of a liquid that occurs only on the surface of a liquid. The other type of vaporization is boiling, which, instead, occurs on the entire mass of the liquid....

of water on earth, and that since clouds disperse rain, clouds and rain are in fact one and the same; in essence, he accurately described the water cycle

Water cycle

The water cycle, also known as the hydrologic cycle or H2O cycle, describes the continuous movement of water on, above and below the surface of the Earth. Water can change states among liquid, vapor, and solid at various places in the water cycle...

Structural engineering and public works

Materials and construction

Timber

Timber may refer to:* Timber, a term common in the United Kingdom and Australia for wood materials * Timber, Oregon, an unincorporated community in the U.S...

was the chief building material in Han architecture. It was used for grand palace halls, multi-story towers, multi-story residential halls, and humble abodes. However, due to wood's rapid decay over time and susceptibility to fire, the oldest wooden buildings found in China (i.e. several temple halls of Mount Wutai) date no earlier than the Tang Dynasty

Tang Dynasty

The Tang Dynasty was an imperial dynasty of China preceded by the Sui Dynasty and followed by the Five Dynasties and Ten Kingdoms Period. It was founded by the Li family, who seized power during the decline and collapse of the Sui Empire...

(618–907 CE). Architectural historian Robert L. Thorp describes the scarcity of Han-era archaeological remains, as well as the often unreliable Han-era literary and artistic sources used by historians for clues about non-existent Han architecture. What remains of Han-dynasty architecture are ruins of brick

Brick

and rammed earth

Rammed earth

walls (including aboveground city walls and underground tomb walls), rammed earth platforms for terraced altars and halls, funerary stone or brick pillar-gates, and scattered ceramic roof tiles

Glazed tile

Glazed tiles were used in China since the Zhou Dynasty as building material for roof top. During the Song Dynasty, the manufacture of glazed tiles was standardized in Li Jie's Architecture Standard...

that once adorned timber halls. Sections of the Han-era rammed earth Great Wall

Great Wall of China

The Great Wall of China is a series of stone and earthen fortifications in northern China, built originally to protect the northern borders of the Chinese Empire against intrusions by various nomadic groups...

still exist in Gansu

Gansu

province, along with the Han frontier ruins of thirty beacon

Beacon

A beacon is an intentionally conspicuous device designed to attract attention to a specific location.Beacons can also be combined with semaphoric or other indicators to provide important information, such as the status of an airport, by the colour and rotational pattern of its airport beacon, or of...

towers and two fortified castle

Castle

A castle is a type of fortified structure built in Europe and the Middle East during the Middle Ages by European nobility. Scholars debate the scope of the word castle, but usually consider it to be the private fortified residence of a lord or noble...

s with crenellations. Han walls of frontier towns and forts in Inner Mongolia

Inner Mongolia

were typically constructed with stamped clay bricks instead of rammed earth.

Thatched or tiled roofs were supported by wooden pillars, since the addition of brick, rammed earth, or mud walls of these halls did not actually support the roof. Stone and plaster

Plaster

Plaster is a building material used for coating walls and ceilings. Plaster starts as a dry powder similar to mortar or cement and like those materials it is mixed with water to form a paste which liberates heat and then hardens. Unlike mortar and cement, plaster remains quite soft after setting,...

were also used for domestic architecture. Tiled eaves projecting outward were built to distance falling rainwater from the walls; they were supported by dougong
Dougong
Dougong is a unique structural element of interlocking wooden brackets, one of the most important elements in traditional Chinese architecture....

brackets that were sometimes elaborately decorated. Molded designs usually decorated the ends of roof tiles, as seen in artistic models of buildings and in surviving tile pieces.

Courtyard homes

Valuable clues about Han architecture can be found in Han artwork of ceramic models, paintings, and carved or stamped bricks discovered in tombs and other sites. The layout of Han tombs were also built like underground houses, comparable to the scenes of courtyard house

Courtyard house

A courtyard house is a type of house — often a large house — where the main part of the building is disposed around a central courtyard. Many houses that have courtyards are not courtyard houses of the type covered by this article. For example, large houses often have small courtyards surrounded by...

s found on tomb bricks and in three-dimensional models. Han homes had a courtyard area (and some had multiple courtyards) with halls that were slightly elevated above it and connected by stairways. Multi-story buildings included the main colonnaded residence halls built around the courtyards as well as watchtower

Watchtower

s. The halls were built with intersecting crossbeams and rafters that were usually carved with decorations; stairways and walls were usually plastered over to produce a smooth surface and then painted.

Chang'an and Luoyang, the Han capitals

The ruins of the walls of Han's first capital Chang'an

Chang'an

still stand today at 12 m (40 ft) in height with a base width of 12 to 16 m (40 to 53 ft). Modern archaeological surveys have proven that the eastern wall was 6,000 m (19,685 ft) long, the southern wall was 7,600 m (24,934 ft) long, the western wall was 4,900 m (16,076 ft) long, and the northern wall was 7,200 (23,622 ft) long. Overall the total length of walls equalled 25,700 m (84,318 ft), and formed a roughly square layout (although the southern and northern walls had sections which zigzag

Zigzag

A zigzag is a pattern made up of small corners at variable angles, though constant within the zigzag, tracing a path between two parallel lines; it can be described as both jagged and fairly regular....

ged due to topographical concerns: rough terrain existed along the southern wall and the course of the Wei River

Wei River

The Wei River is a major river in west-central China's Gansu and Shaanxi provinces. It is the largest tributary of the Yellow River and very important in the early development of Chinese civilization....

obstructed the straight path of the northern wall). The city's moat

Moat

A moat is a deep, broad ditch, either dry or filled with water, that surrounds a castle, other building or town, historically to provide it with a preliminary line of defence. In some places moats evolved into more extensive water defences, including natural or artificial lakes, dams and sluices...

was 8 m (26 ft) wide and 3 m (10 ft) deep; the remains of what were wooden bridges have been discovered along the moat. Chang'an had twelve gatehouse

Gatehouse

A gatehouse, in architectural terminology, is a building enclosing or accompanying a gateway for a castle, manor house, fort, town or similar buildings of importance.-History:...

s leading into the city, three for each side of the wall, and acted as terminus points for the main avenues. Every gatehouse had three gateway entrances that were each 6 m (20 ft) wide; Han-era writers claimed that each gateway could accommodate the traffic of four horse-drawn carriages at once. The drainage system

Sewage collection and disposal

Sewage collection and disposal systems transport sewage through cities and other inhabited areas to sewage treatment plants to protect public health and prevent disease. Sewage is treated to control water pollution before discharge to surface waters....

included many drainholes that were dug under these gates and lined with bricks that form arches, where ceramic water pipe

Water pipe

Water pipes are pipes or tubes, frequently made of polyvinyl chloride , ductile iron, steel, cast iron, polypropylene, polyethylene, or copper, that carry pressurized and treated fresh water to buildings , as well as inside the building.-History:For many centuries, lead was the favoured material...

s have been found that once connected to the ditches built alongside the major streets. Only some wall sections and platform foundations of the city's once lavish imperial palaces remain. Likewise, the stone foundations of the armory were also discovered, but its wooden architecture had long since disappeared.
Some sections of the wall ruins of Han's second capital Luoyang

Luoyang

still stand at 10 m (32 ft) in height and 25 m (82 ft) in width at the base. The eastern wall was 3,900 m (12,795 ft) long, the western wall was 3,400 m (11,155 ft) long, and the northern wall was 2,700 m (8,858 ft) long, yet the southern wall was washed away when the Luo River

Luo River (Henan)

The Luo River is a tributary of the Yellow River in China. It rises in the southeast flank of Huashan in Shaanxi province and flows east into Henan province, where it eventually joins the Yellow River at the city of Gongyi...

changed its course centuries ago; by using the terminus points of the eastern and western walls, historians estimate that the southern wall was 2,460 m (8,070 ft) long. The overall walled enclosure formed a rectangular shape, yet with some disruptive curves due to topographical obstructions. Like Chang'an, Luoyang had twelve gatehouses, three for each side of the wall, while each gatehouse had three gateway entrances which led to major avenues within the city. The rammed earth foundational platforms of religious altars and terraces still stand today outside of the walled perimeter of Luoyang, dedicated to the worship of deities

Society and culture of the Han Dynasty

The Han Dynasty was a period of ancient China divided by the Western Han and Eastern Han periods, when the capital cities were located at Chang'an and Luoyang, respectively. It was founded by Emperor Gaozu of Han and briefly interrupted by the regime of Wang Mang The Han Dynasty (206 BCE –...

and where state sacrifices were conducted. They were approached by long ramps and once had timber halls built on top with verandas on the lower levels.

Underground tombs

By the 1980s, over ten thousand brick-and-stone underground Han tombs had been discovered throughout China. Earlier Chinese tombs dating to the Warring States were often vertically dug pits lined with wooden walls. In digging the tomb sites, Han workers would first build vertical pits and then dig laterally, hence the name "horizontal pits" for Han tombs; this method was also used for tomb sites dug into the sides of mountains. The walls of most Western Han tombs were built of large hollow bricks while the smaller, non-hollow brick type that dominated Eastern Han tomb architecture (with some made out of stone) appeared in the late Western Han. The smaller brick type was better-suited for Han tomb arch

Arch

An arch is a structure that spans a space and supports a load. Arches appeared as early as the 2nd millennium BC in Mesopotamian brick architecture and their systematic use started with the Ancient Romans who were the first to apply the technique to a wide range of structures.-Technical aspects:The...

ways at entrances, vaulted

Vault (architecture)

A Vault is an architectural term for an arched form used to provide a space with a ceiling or roof. The parts of a vault exert lateral thrust that require a counter resistance. When vaults are built underground, the ground gives all the resistance required...

chambers, and dome

Dome

A dome is a structural element of architecture that resembles the hollow upper half of a sphere. Dome structures made of various materials have a long architectural lineage extending into prehistory....

d roofs. Underground vaults and domes did not require buttress supports since they were held in place by earthen pits. The use of brick vaults and domes in aboveground Han structures is unknown.

The layout of tombs dug into the sides of mountains typically had a front chamber, side chambers, and a rear chambers designed to imitate a complex of aboveground halls. The tomb of King Liu Sheng

Liu Sheng

Liu Sheng , Prince Jing of Zhongshan , was a Chinese prince of the Western Han dynasty. His father was Emperor Jing, and he was the elder brother of Emperor Wu of Han...

(d. 113 BCE) in Hebei

Hebei

' is a province of the People's Republic of China in the North China region. Its one-character abbreviation is "" , named after Ji Province, a Han Dynasty province that included what is now southern Hebei...

province not only had a front hall with window drapes and grave goods, carriages and horses in the southern separate side chamber, and storage goods in the northern side chamber, but also the remains of real timber houses with tiled roofs erected within (along with a house made of stone slabs and two stone doors in the rear chamber). Doors made completely out of stone were found in many Han tombs as well as tombs in later dynasties

Qianling Mausoleum

The Qianling Mausoleum is a Tang Dynasty tomb site located in Qian County, Shaanxi province, China, and is northwest from Xi'an, formerly the Tang capital. Built by 684 , the tombs of the mausoleum complex house the remains of various members of the royal Li family. This includes Emperor...

.

A total of twenty-nine monumental brick or stone-carved pillar-gates (que
Que (tower)
Que is a freestanding, ceremonial gate tower in traditional Chinese architecture. First developed in the Zhou Dynasty, que towers were used to form ceremonial gateways to tombs, palaces and temples throughout pre-modern China down to the Qing Dynasty...

) from the Han Dynasty have survived and can be found in the aboveground areas around Han tomb and shrine sites. They often formed part of outer walls, usually flanking an entry but sometimes at the corners of walled enclosures. Although they lack wooden and ceramic components, they feature imitation roof tiles, eaves, porches, and balustrades

Baluster

A baluster is a moulded shaft, square or of lathe-turned form, one of various forms of spindle in woodwork, made of stone or wood and sometimes of metal, standing on a unifying footing, and supporting the coping of a parapet or the handrail of a staircase. Multiplied in this way, they form a...

Boreholes and mining shafts

On Han tomb brick reliefs of Sichuan

Sichuan

' , known formerly in the West by its postal map spellings of Szechwan or Szechuan is a province in Southwest China with its capital in Chengdu...

province, scenes of borehole

Borehole

drilling for mining

Mining

Mining is the extraction of valuable minerals or other geological materials from the earth, from an ore body, vein or seam. The term also includes the removal of soil. Materials recovered by mining include base metals, precious metals, iron, uranium, coal, diamonds, limestone, oil shale, rock...

projects are shown. They show towering derrick

Derrick

s lifting liquid brine

Brine

through bamboo pipes

Pipeline transport

Pipeline transport is the transportation of goods through a pipe. Most commonly, liquids and gases are sent, but pneumatic tubes that transport solid capsules using compressed air are also used....

to the surface so that the brine could be distilled

Distillation

Distillation is a method of separating mixtures based on differences in volatilities of components in a boiling liquid mixture. Distillation is a unit operation, or a physical separation process, and not a chemical reaction....

in evaporation pans over the heat of furnaces and produce salt

Salt

In chemistry, salts are ionic compounds that result from the neutralization reaction of an acid and a base. They are composed of cations and anions so that the product is electrically neutral...

. The furnaces were heated by natural gas

Natural gas

brought by bamboo pipes, yet gas brought up from 610 m (2,000 ft) below the surface could cause an explosion if it was not properly mixed with oxygen first, so the Han-era Chinese built underground carburetor

Carburetor

A carburetor , carburettor, or carburetter is a device that blends air and fuel for an internal combustion engine. It is sometimes shortened to carb in North America and the United Kingdom....

chambers and siphoned some of the gas off with exhaust pipes

Exhaust system

An exhaust system is usually tubing used to guide reaction exhaust gases away from a controlled combustion inside an engine or stove. The entire system conveys burnt gases from the engine and includes one or more exhaust pipes...

. The drill bit for digging boreholes was operated by a team of men jumping on and off a beam while the boring tool was rotated by a draft animal, usually oxen or water buffalo

Water buffalo

The water buffalo is a domesticated bovid widely kept in Asia, Europe and South America.Water buffalo can also refer to:*Wild water buffalo , the wild ancestor of the domestic water buffalo...

es. Han boreholes dug for collecting brine could reach hundreds of meters (feet) beneath the Earth's surface. Mining shafts

Shaft mining

Shaft mining or shaft sinking refers to the method of excavating a vertical or near-vertical tunnel from the top down, where there is initially no access to the bottom....

dating to the Han Dynasty have been found which reach depths of hundreds of meters (feet) beneath the earth, complete with spacious underground rooms structured by timber frames along with ladders and iron tools left behind.

Ceramic model buildings

There are Han-era literary references to tall towers found in the capital cities; they often served as watchtowers, astronomical observatories

Observatory

An observatory is a location used for observing terrestrial or celestial events. Astronomy, climatology/meteorology, geology, oceanography and volcanology are examples of disciplines for which observatories have been constructed...

, and religious establishments meant to attract the favor of immortals

Xian (Taoism)

Xian is a Chinese word for an enlightened person, translatable in English as:*"spiritually immortal; transcendent; super-human; celestial being"...

. The court eunuchs Zhao Zhong

Zhao Zhong

Zhào Zhōng was a eunuch of the late Han Dynasty, who served Emperor Ling of Han the Ten regular attendants . The eunuchs who had gained considerable power in the Han imperial court...

and Zhang Rang

Zhang Rang

discouraged the aloof Emperor Ling of Han

Emperor Ling of Han

Emperor Ling of Han, trad. ch. 漢靈帝;, sim. ch. 汉灵帝, py. hàn líng dì, wg. Han Ling-ti, was an emperor of the Chinese Han Dynasty. He was a great-great-grandson of Emperor Zhang. The Yellow Turban Rebellion broke out during Emperor Ling's reign.Emperor Ling's reign saw yet another repetition of...

(r. 168–189 CE) from ascending to the top floors of tall towers (claiming it would cause bad luck), in order to conceal from him the enormous palatial mansions the eunuchs built for themselves in Luoyang. It is not known for certain whether or not miniature ceramic models of residential towers and watchtowers found in Han-dynasty tombs are completely faithful representations of such timber towers, yet they reveal vital clues about lost timber architecture.

There are only a handful of existing ceramic models of multi-story towers from pre-Han and Western Han eras; the bulk of the hundreds of towers found so far were made during the Eastern Han period. Model towers could be fired as one piece in the kiln or assembled from several different ceramic pieces to create the whole. No one tower is a duplicate of the other, yet they share common features. They often had a walled courtyard at the bottom, a balcony with balustrades and windows for every floor, roof tiles capping and concealing the ceiling rafter

Rafter

A rafter is one of a series of sloped structural members , that extend from the ridge or hip to the downslope perimeter or eave, designed to support the roof deck and its associated loads.-Design:...

s, human figures peering out the windows or standing on the balconies, door knocker

Door knocker

A door knocker is an item of door furniture that allows people outside a house to alert those inside to their presence. A door knocker has a part fixed to the door, and a part which is attached to the door by a hinge, and may be lifted and used to strike a plate fitted to the door, or the door...

s, and pets such as dogs

Dogs in ancient China

Dogs , known in Classical Chinese as quan , played an important role in ancient Chinese society.- Domestication :...

in the bottom courtyard. Perhaps the most direct pieces of evidence to suggest that miniature ceramic tower models are faithful representations of real-life Han timber towers are tile patterns. Artistic patterns found on the circular tiles that cap the eave-ends on the miniature models are exact matches of patterns found on real-life Han roof tiles excavated at sites such as the royal palaces in Chang'an and Luoyang, and even the tiles of the original White Horse Temple

White Horse Temple

White Horse Temple is, according to tradition, the first Buddhist temple in China, established in 68 AD under the patronage of Emperor Ming in the Eastern Han capital Luoyang. Today the site is located just outside the walls of the ancient Eastern Han capital, some east of Luoyang in Henan...

. The ceramic model towers featured below come from tombs of the Han Dynasty:
Besides towers, other ceramic models from the Han reveal a variety of building types. This includes multi-story storehouses

Warehouse

A warehouse is a commercial building for storage of goods. Warehouses are used by manufacturers, importers, exporters, wholesalers, transport businesses, customs, etc. They are usually large plain buildings in industrial areas of cities and towns. They usually have loading docks to load and unload...

such as granaries

Granary

A granary is a storehouse for threshed grain or animal feed. In ancient or primitive granaries, pottery is the most common use of storage in these buildings. Granaries are often built above the ground to keep the stored food away from mice and other animals.-Early origins:From ancient times grain...

, courtyard houses with multi-story halls, kiosk

Kiosk

Kiosk is a small, separated garden pavilion open on some or all sides. Kiosks were common in Persia, India, Pakistan, and in the Ottoman Empire from the 13th century onward...

s, walled gate towers, mills, manufactories and workshop

Workshop

A workshop is a room or building which provides both the area and tools that may be required for the manufacture or repair of manufactured goods...

s, animal pens, outhouse

Outhouse

An outhouse is a small structure separate from a main building which often contained a simple toilet and may possibly also be used for housing animals and storage.- Terminology :...

s, and water wells. Even models of single-story farmhouse

Farmhouse

Farmhouse is a general term for the main house of a farm. It is a type of building or house which serves a residential purpose in a rural or agricultural setting. Most often, the surrounding environment will be a farm. Many farm houses are shaped like a T...

s show a great amount of detail, including tiled roofs, courtyards, steps leading to walkways, farmyards with troughs and basins, parapets, and privies. Models of granaries and storehouses had tiled rooftops, dougong brackets, windows, and stilt supports raising them above ground level. Han models of water wells sometimes feature tiny tiled roofs supported by beams that house the rope pulley

Pulley

A pulley, also called a sheave or a drum, is a mechanism composed of a wheel on an axle or shaft that may have a groove between two flanges around its circumference. A rope, cable, belt, or chain usually runs over the wheel and inside the groove, if present...

used for lifting the bucket. The ceramic models featured below come from tombs of the Han Dynasty:

Roads, bridges, and canals

In order to facilitate commerce and communication as well as speed the process of tax collection and movement of military troops, the Han government sponsored the building of new roads, bridges, and canal waterways. These include repairs and renovation work on the Dujiangyan Irrigation System

Dujiangyan Irrigation System

Dujiangyan is an irrigation infrastructure built in 256 BC during the Warring States Period of China by the Kingdom of Qin. It is located in the Min River in Sichuan province, China, near the capital Chengdu. It is still in use today to irrigate over 5,300 square kilometers of land in the region...

of Sichuan

Sichuan

' , known formerly in the West by its postal map spellings of Szechwan or Szechuan is a province in Southwest China with its capital in Chengdu...

and Zhengguo Canal

Zhengguo Canal

The Zhengguo Canal, Zhengguoqu or Chengkuo Canal , named after its designer, Zheng Guo, is a large canal located in Shaanxi province, China. The canal irrigates the Guanzhong plain, north of Xi'an. Together with the Dujiangyan Irrigation System and Lingqu Canal, it is one of the three biggest water...

of Shaanxi

Shaanxi

' is a province in the central part of Mainland China, and it includes portions of the Loess Plateau on the middle reaches of the Yellow River in addition to the Qinling Mountains across the southern part of this province...

, both of which were built by the previous State of Qin. Accepting the proposal of Er Kuan (兒寬), in 111 BCE Emperor Wu commissioned Er to lead the project of creating extensions to the Zhengguo Canal that could irrigate nearby terrain elevated above the main canal. Since a large amount of silt

Silt

Silt is granular material of a size somewhere between sand and clay whose mineral origin is quartz and feldspar. Silt may occur as a soil or as suspended sediment in a surface water body...

had built up over time at the bottom of the Zhengguo Canal (causing flooding), in 95 BCE another project was initiated to tap irrigation waters from further up the Jing River, requiring the dredging of a new 100 km (62 mi) long canal following a contour line

Contour canal

A contour canal is an artificially-dug navigable canal which closely follows the contour line of the land it traverses in order to avoid costly engineering works such as boring a tunnel through higher ground, building an embankment over lower ground, or constructing a canal lock to change the...

above the Zhengguo.

Roadways, wooden bridges, postal stations, and relay stations were occasionally repaired, while many new facilities such as these were established. As written by Han authors, roads built during the Han were tamped down with metal rammers, yet there is uncertainty over the materials used; Joseph Needham

Joseph Needham

speculates that they were rubble and gravel. The widths of roads ranged from narrow footpaths where only a single horse or oxen could pass at once to large highways that could accommodate the simultaneous passage of nine horse-drawn chariots abreast. Fortified Han roadways were built as far west as Shanshan

Shanshan

Shanshan is the Chinese name for a kingdom that existed roughly from 200 BCE-1000 CE at the north-eastern end of the Taklamakan Desert including the great, but now mostly dry, salt lake known as Lop Nur....

(Loulan) near the Lop Desert

Lop Desert

The Lop Desert or Lop Nur or Lop Nor, is a desert extending from Korla eastwards along the foot of the Kuruktagh to the formerly terminal Tarim Basin in the Xinjiang Uygur Autonomous Region of China. It is an almost perfectly horizontal expanse...

, while Han forces

Protectorate of the Western Regions

The Protectorate of the Western Regions was a regional government established by the Han Dynasty to manage and to control the Western Regions, roughly today's Xinjiang ....

utilized routes that traversed north of the Taklamakan Desert towards Kashgar

Kashgar

Kashgar or Kashi is an oasis city with approximately 350,000 residents in the western part of the Xinjiang Uyghur Autonomous Region of the People's Republic of China. Kashgar is the administrative centre of Kashgar Prefecture which has an area of 162,000 km² and a population of approximately...

. A vast network of roads, fortified passes, and wooden bridges built over rushing torrents in steep gorges of the Qin Mountains was consolidated during the Han, known as the gallery road

Gallery road

The archaeological gallery roads were roads through remote mountain areas of China. They consisted of wooden planks erected on holes cut into the sides of cliffs. They were most notably used in the Qin Mountains linking the Wei River and the Han River valleys. The first gallery roads were built...

s. During the reign of Emperor Wu, roads were built to connect newly conquered territories in what is now Yunnan

Yunnan

in the far southwest as well as the Korean Peninsula

Korean Peninsula

The Korean Peninsula is a peninsula in East Asia. It extends southwards for about 684 miles from continental Asia into the Pacific Ocean and is surrounded by the Sea of Japan to the south, and the Yellow Sea to the west, the Korea Strait connecting the first two bodies of water.Until the end of...

in the far northeast.

One of the most common bridge-types built during the Han was the wooden-trestle beam bridge

Beam bridge

, described by literary sources and seen in reliefs carved on tomb bricks. Evidence for arch bridge

Arch bridge

s is elusive: one outside of Chengdu

Chengdu

Chengdu , formerly transliterated Chengtu, is the capital of Sichuan province in Southwest China. It holds sub-provincial administrative status...

's south gate is claimed to date to the Han period, while that built by Ma Xian (馬賢) (fl. 135 CE) was certainly a beam bridge. In artwork, a relief sculpture from a Han tomb in Sichuan province shows an arch bridge with a gradual curve, suggesting that it is segmental, although the use of such bridges are not entirely confirmed. Although there are rare references to simple suspension bridge

Simple suspension bridge

A simple suspension bridge is an early type of bridge that is supported entirely from anchors at either end, and has no towers or piers. However, it may have saddles...

s in Han sources, these are only mentioned in connection with travels to foreign countries in the Himalaya, Hindukush and Afghanistan

Afghanistan

Afghanistan , officially the Islamic Republic of Afghanistan, is a landlocked country located in the centre of Asia, forming South Asia, Central Asia and the Middle East. With a population of about 29 million, it has an area of , making it the 42nd most populous and 41st largest nation in the world...

, demonstrating the antiquity of the invention there. Floating pontoon bridge

Pontoon bridge

s made of boats secured by iron chains were built during the Han (some even spanning the Yellow River

Yellow River

The Yellow River or Huang He, formerly known as the Hwang Ho, is the second-longest river in China and the sixth-longest in the world at the estimated length of . Originating in the Bayan Har Mountains in Qinghai Province in western China, it flows through nine provinces of China and empties into...

and Yangzi River) and were most often employed for military purposes since they could be easily assembled and then disassembled.

Medicine

Much of the beliefs held by Han-era physicians are known to modern historians through such texts as the Yellow Emperor's Inner Canon (Huangdi neijing) medical corpus, which was compiled from the 3rd to 2nd century BCE and was mentioned in the Book of Later Han. It is clear from this text and others that their metaphysical beliefs in the five phases and yin and yang

Yin and yang

In Asian philosophy, the concept of yin yang , which is often referred to in the West as "yin and yang", is used to describe how polar opposites or seemingly contrary forces are interconnected and interdependent in the natural world, and how they give rise to each other in turn. Opposites thus only...

dictated their medical decisions and assumptions. The Han-era Chinese believed that each organ in the body was associated with one of the five phases (metal 金, wood 木, water 水, fire 火, earth 土) and had two circulatory qi channels (任督二脉). If these channels were disrupted, Han medical texts suggest that one should consume an edible material associated with one of these phases that would counteract the organ's prescribed phase and thus restore one's health. For example, the Chinese believed that when the heart—associated with the fire phase—caused one to become sluggish, then one should eat sour food because it was associated with the wood phase (which promoted fire). The Han Chinese also believed that by using pulse diagnosis

Pulse diagnosis

Pulse diagnosis is a technique used in traditional medicines such as in Ayurveda, Chinese medicine, or early Greek medicine.In Ayurveda, advocates claim that by taking a pulse examination, humoral imbalances such as the three Doshas - Vata, Pitta, and Kaphha - can be diagnosed.In Traditional...

, a physician could determine which organ of the body emitted "vital energy

In traditional Chinese culture, qì is an active principle forming part of any living thing. Qi is frequently translated as life energy, lifeforce, or energy flow. Qi is the central underlying principle in traditional Chinese medicine and martial arts...

" (qi) and what qualities the latter had, in order to figure out the exact disorder the patient was suffering. Despite the influence of metaphysical theory on medicine, Han texts also give practical advice, such as the proper way to perform clinical lancing

Clinical lancing

Clinical lancing is a procedure used to evacuate non-beneficial subcutaneous fluid accumulations, such as pustules or boils, if they remain in place once they have finished sequestering fluid from the surrounding areas, using a sterilised needle. Incision and drainage is a more general term for...

to remove an abscess

Abscess

An abscess is a collection of pus that has accumulated in a cavity formed by the tissue in which the pus resides due to an infectious process or other foreign materials...

. The Huangdi neijing noted the symptoms and reactions of people with various diseases of the liver, heart, spleen, lung, or kidneys in a 24-hour period, which was a recognition of circadian rhythm

Circadian rhythm

A circadian rhythm, popularly referred to as body clock, is an endogenously driven , roughly 24-hour cycle in biochemical, physiological, or behavioural processes. Circadian rhythms have been widely observed in plants, animals, fungi and cyanobacteria...

, although explained in terms of the five phases.

In his Essential Medical Treasures of the Golden Chamber
Jinkui Yaolue
Jingui Yaolue , Synopsis of Golden Chamber in medical book or Essential Medical Treasures of the Golden Chamber in prescription book is a classic clinical book of traditional Chinese medicine written by Zhang Zhongjing at the end of the Eastern Han Dynasty and was first published in the Northern...

(Jinkui yaolue), Zhang Zhongjing

Zhang Zhongjing

Zhang Zhongjing , formal name Zhang Ji, was a Han Dynasty physician and one of the most eminent Chinese physicians during the later years of the Han Dynasty...

(c. 150 – c. 219 CE) was the first to suggest a regulated diet rich in certain vitamin

Vitamin

A vitamin is an organic compound required as a nutrient in tiny amounts by an organism. In other words, an organic chemical compound is called a vitamin when it cannot be synthesized in sufficient quantities by an organism, and must be obtained from the diet. Thus, the term is conditional both on...

s could prevent different types of disease, an idea which led Hu Sihui

Hu Sihui

Hu Sihui was a court therapist and dietitian during Yuan Dynasty reign in China. He is known for his book Yinshan Zhengyao , that became a classic in Chinese medicine and Chinese cuisine...

(fl. 1314–1330 CE) to prescribe a diet rich in Vitamin B₁ as a treatment for beriberi

Beriberi

Beriberi is a nervous system ailment caused by a thiamine deficiency in the diet. Thiamine is involved in the breakdown of energy molecules such as glucose and is also found on the membranes of neurons...

. Zhang's major work was the Treatise on Cold Injury and Miscellaneous Disorders

Shang Han Lun

The Shang Han Lun or Shang Han Za Bing Lun , known in English as the Treatise on Cold Damage Disorders or the Treatise on Cold Injury, is a Chinese medical treatise that was compiled by Zhang Zhongjing sometime before the year 220, at the end of the Han dynasty...

(Shanghan zabing lun). His contemporary and alleged associate Hua Tuo

Hua Tuo

Hua Tuo was an ancient Chinese physician who lived during the late Han Dynasty and Three Kingdoms era of Chinese history. The Records of Three Kingdoms and Book of Later Han record Hua as the first person in China to use anesthesia during surgery. He used a general anesthetic combining wine with a...

(d. 208 CE) was a physician who had studied the Huangdi neijing and became knowledgeable in Chinese herbology

Chinese herbology

Chinese Herbology is the theory of Traditional Chinese herbal therapy, which accounts for the majority of treatments in Traditional Chinese medicine ....

. Hua Tuo used anesthesia

Anesthesia

Anesthesia, or anaesthesia , traditionally meant the condition of having sensation blocked or temporarily taken away...

on patients during surgery

Surgery

Surgery is an ancient medical specialty that uses operative manual and instrumental techniques on a patient to investigate and/or treat a pathological condition such as disease or injury, or to help improve bodily function or appearance.An act of performing surgery may be called a surgical...

and created an ointment that was meant to fully heal surgery wounds within a month. In one diagnosis of an ill woman, he deciphered that she bore a dead fetus

Fetus

A fetus is a developing mammal or other viviparous vertebrate after the embryonic stage and before birth.In humans, the fetal stage of prenatal development starts at the beginning of the 11th week in gestational age, which is the 9th week after fertilization.-Etymology and spelling variations:The...

within her womb which he then removed, curing her of her ailments.

Historical sources say that Hua Tuo rarely practiced moxibustion

Moxibustion

Moxibustion is a traditional Chinese medicine therapy using moxa, or mugwort herb. It plays an important role in the traditional medical systems of China, Japan, Korea, Vietnam, Tibet, and Mongolia. Suppliers usually age the mugwort and grind it up to a fluff; practitioners burn the fluff or...

and acupuncture

Acupuncture

Acupuncture is a type of alternative medicine that treats patients by insertion and manipulation of solid, generally thin needles in the body....

. The first mentioning of acupuncture in Chinese literature appeared in the Huangdi neijing. Acupuncture needles made of gold were found in the tomb of the Han King Liu Sheng

Liu Sheng

Liu Sheng , Prince Jing of Zhongshan , was a Chinese prince of the Western Han dynasty. His father was Emperor Jing, and he was the elder brother of Emperor Wu of Han...

(d. 113 BCE). Some stone-carved depictions of acupuncture date to the Eastern Han Era (25–220 CE). Hua Tuo also wrote about the allegedly life-prolonging exercises of calisthenics

Calisthenics

. In the 2nd-century-BCE medical texts excavated from the tombs of Mawangdui, illustrated diagrams of calisthenic positions are accompanied by descriptive titles and captions. Vivienne Lo writes that the modern physical exercises of taijiquan and qigong

Qigong

Qigong or chi kung is a practice of aligning breath, movement, and awareness for exercise, healing, and meditation...

are derived from Han-era calisthenics.

Cartography

Map

A map is a visual representation of an area—a symbolic depiction highlighting relationships between elements of that space such as objects, regions, and themes....

-making

Cartography

Cartography is the study and practice of making maps. Combining science, aesthetics, and technique, cartography builds on the premise that reality can be modeled in ways that communicate spatial information effectively.The fundamental problems of traditional cartography are to:*Set the map's...

in China preceded the Han Dynasty. Since two 4th-century-BCE silk maps from the State of Qin

Qin (state)

The State of Qin was a Chinese feudal state that existed during the Spring and Autumn and Warring States Periods of Chinese history...

(found in Gansu

Gansu

, displaying the region about the Jialing River

Jialing River

The Jialing River is a tributary of the Yangtze River with its source in Gansu province. It gets its name from its crossing the Jialing Vale in Feng County of Shaanxi. It was once known as Langshui or Yushui .-Overview:...

) show the measured distance

Li (unit)

The li is a traditional Chinese unit of distance, which has varied considerably over time but now has a standardized length of 500 meters or half a kilometer...

between timber-gathering sites, Mei-ling Hsu argues that these are to be considered the first known economic maps

Economic geography

Economic geography is the study of the location, distribution and spatial organization of economic activities across the world. The subject matter investigated is strongly influenced by the researcher's methodological approach. Neoclassical location theorists, following in the tradition of Alfred...

(as they predate the maps of the Roman

Ancient Rome

geographer Strabo

Strabo

Strabo, also written Strabon was a Greek historian, geographer and philosopher.-Life:Strabo was born to an affluent family from Amaseia in Pontus , a city which he said was situated the approximate equivalent of 75 km from the Black Sea...

, c. 64 BCE – 24 CE). Maps from the Han period have also been uncovered by modern archaeologists, such as those found with 2nd-century-BCE silk texts

Mawangdui Silk Texts

at Mawangdui. In contrast to the Qin maps, the Han maps found at Mawangdui employ a more diverse use of map symbols, cover a larger terrain, and display information on local populations and even pinpoint locations of military camps. One of the maps discovered at Mawangdui shows positions of Han military garrisons which were to attack Nanyue

Nanyue

Nanyue was an ancient kingdom that consisted of parts of the modern Chinese provinces of Guangdong, Guangxi, and Yunnan and northern Vietnam. Nanyue was established in 204 BC at the final collapse of the Qin Dynasty by Zhao Tuo, who was the military commander of Nanhai Commandery at the time, and...

in 181 BCE.

In Chinese literature

Chinese literature

Chinese literature extends thousands of years, from the earliest recorded dynastic court archives to the mature fictional novels that arose during the Ming Dynasty to entertain the masses of literate Chinese...

, the oldest reference to a map comes from the year 227 BCE, when the assassin Jing Ke

Jing Ke

Jing Ke was a guest residing in the estates of Dan, crown prince of Yan and renowned for his failed assassination attempt of Ying Zheng, King of Qin state, who later became China's first emperor...

was to present a map to Ying Zheng 嬴政, King of Qin (ruling later as Qin Shi Huang

Qin Shi Huang

Qin Shi Huang , personal name Ying Zheng , was king of the Chinese State of Qin from 246 BC to 221 BC during the Warring States Period. He became the first emperor of a unified China in 221 BC...

, r. 221–210 BCE) on behalf of Crown Prince Dan of Yan

Crown Prince Dan of Yan

Crown Prince Dan of Yan was a crown prince of the state of Yan during the Warring States Period in China. Originally a hostage in the State of Qin, he was sent back to Yan in 232 BC. He sent Jing Ke to assassinate Qin Shi Huang, then Emperor of China, but he failed...

. Instead of presenting the map, he pulled out a dagger from his scroll, yet was unable to kill Ying Zheng. The Rites of Zhou
Rites of Zhou
The Rites of Zhou , also known as Zhouguan, is one of three ancient ritual texts listed among the classics of Confucianism. It was later renamed Zhouli by Liu Xin to differentiate it from a chapter in the Classic of History which was also known as Zhouguan.Though tradition ascribed the text of the...

(Zhouli), compiled during the Han and commented by Liu Xin in the 1st century CE, mentioned the use of maps for governmental provinces and districts, principalities, frontier boundaries, and locations of ores and minerals for mining facilities. The first Chinese gazetteer

Gazetteer

A gazetteer is a geographical dictionary or directory, an important reference for information about places and place names , used in conjunction with a map or a full atlas. It typically contains information concerning the geographical makeup of a country, region, or continent as well as the social...

was written in 52 CE and included information on territorial divisions, the founding of cities, and local products and customs. Pei Xiu

Pei Xiu

Pei Xiu , style name Jiyan , was a minister, geographer, and cartographer of the state of Cao Wei during the Three Kingdoms period of Chinese history, as well as the subsequent Jin Dynasty. Pei Xiu was very much trusted by Sima Zhao, and participated in the suppression of Zhuge Dan's coup...

(224–271 CE) was the first to describe in detail the use of a graduated scale

Scale (map)

The scale of a map is defined as the ratio of a distance on the map to the corresponding distance on the ground.If the region of the map is small enough for the curvature of the Earth to be neglected, then the scale may be taken as a constant ratio over the whole map....

and geometrically plotted reference grid

Grid reference

Grid references define locations on maps using Cartesian coordinates. Grid lines on maps define the coordinate system, and are numbered to provide a unique reference to features....

. However, historians Howard Nelson, Robert Temple, and Rafe de Crespigny

Rafe de Crespigny

Dr Rafe de Crespigny is a retired Adjunct Professor with the China and Korea Centre, Australian National University in Canberra, Australia...

argue that there is enough literary evidence that Zhang Heng's now lost work of 116 CE established the geometric reference grid in Chinese cartography (including a line from the Book of Later Han: "[Zhang Heng] cast a network of coordinates about heaven and earth, and reckoned on the basis of it"). Although there is speculation fueled by the report in Sima's Records of the Grand Historian that a gigantic raised-relief map

Raised-relief map

representing the Qin Empire is located within the tomb of Qin Shi Huang, it is known that small raised-relief maps were created during the Han Dynasty, such as one made out of rice by the military officer Ma Yuan (14 BCE – 49 CE).

Nautics and vehicles

In 1975, an ancient shipyard

Shipyard

Shipyards and dockyards are places which repair and build ships. These can be yachts, military vessels, cruise liners or other cargo or passenger ships. Dockyards are sometimes more associated with maintenance and basing activities than shipyards, which are sometimes associated more with initial...

discovered in Guangzhou

Guangzhou

Guangzhou , known historically as Canton or Kwangchow, is the capital and largest city of the Guangdong province in the People's Republic of China. Located in southern China on the Pearl River, about north-northwest of Hong Kong, Guangzhou is a key national transportation hub and trading port...

is now dated to the late 3rd century BCE, made during either the Qin Dynasty

Qin Dynasty

(221–206 BCE) or early Western Han Dynasty. It had three large platforms capable of building wooden ships that were 30 m (98 ft) long, 8 m (26 ft) wide, and had a weight capacity of 60 metric tons. Another Han shipyard in what is now Anhui

Anhui

Anhui is a province in the People's Republic of China. Located in eastern China across the basins of the Yangtze River and the Huai River, it borders Jiangsu to the east, Zhejiang to the southeast, Jiangxi to the south, Hubei to the southwest, Henan to the northwest, and Shandong for a tiny...

province had a government-operated maritime workshop where battle ships were assembled. The widespread use of iron tools during the Han Dynasty was essential for crafting such vessels.

In 111 BCE, Emperor Wu conquered the Kingdom of Nanyue

Nanyue

in what is now modern northern Vietnam

Northern and southern Vietnam

Northern Vietnam and Southern Vietnam are two general regions within Vietnam.Of the two regions, the older is Northern Vietnam, where the Vietnamese culture originated over 2000 years ago in the Red River Delta, though Vietnamese people eventually spread south into the Mekong Delta...

and Guangdong

Guangdong

Guangdong is a province on the South China Sea coast of the People's Republic of China. The province was previously often written with the alternative English name Kwangtung Province...

, Guangxi

Guangxi

, Yunnan

Yunnan

; thereafter he opened up maritime trade to both Southeast Asia

Southeast Asia

Southeast Asia, South-East Asia, South East Asia or Southeastern Asia is a subregion of Asia, consisting of the countries that are geographically south of China, east of India, west of New Guinea and north of Australia. The region lies on the intersection of geological plates, with heavy seismic...

and the Indian Ocean

Indian Ocean

The Indian Ocean is the third largest of the world's oceanic divisions, covering approximately 20% of the water on the Earth's surface. It is bounded on the north by the Indian Subcontinent and Arabian Peninsula ; on the west by eastern Africa; on the east by Indochina, the Sunda Islands, and...

, as foreign merchants brought lapis lazuli

Lapis lazuli

Lapis lazuli is a relatively rare semi-precious stone that has been prized since antiquity for its intense blue color....

, pearl

Pearl

A pearl is a hard object produced within the soft tissue of a living shelled mollusk. Just like the shell of a mollusk, a pearl is made up of calcium carbonate in minute crystalline form, which has been deposited in concentric layers. The ideal pearl is perfectly round and smooth, but many other...

s, jade

Jade

Jade is an ornamental stone.The term jade is applied to two different metamorphic rocks that are made up of different silicate minerals:...

, and glass

Glass

Glass is an amorphous solid material. Glasses are typically brittle and optically transparent.The most familiar type of glass, used for centuries in windows and drinking vessels, is soda-lime glass, composed of about 75% silica plus Na2O, CaO, and several minor additives...

wares to the Han Empire from this southern sea route. When a group of travelers from the Roman Empire

Roman Empire

The Roman Empire was the post-Republican period of the ancient Roman civilization, characterised by an autocratic form of government and large territorial holdings in Europe and around the Mediterranean....

(allegedly diplomats of Marcus Aurelius but most likely Roman merchants

Roman commerce

Roman trade was the engine that drove the Roman economy of the late Republic and the early Empire. Fashions and trends in historiography and in popular culture have tended to neglect the economic basis of the empire in favor of the lingua franca of Latin and the exploits of the Roman legions...

) came to the Han court in 166 CE

History of the Han Dynasty

, they allegedly came from this southern trade route. By at least the 1st century CE — as proven by Eastern Han ceramic miniature models of ships found in various tombs — the Chinese would have been able to brave distant waters with the new steering

Steering

Steering is the term applied to the collection of components, linkages, etc. which will allow a vessel or vehicle to follow the desired course...

invention of the stern-mounted rudder

Rudder

. This came to replace the less efficient steering oar

Steering oar

The steering oar or steering board is an oversized oar or board to control the direction of a ship or other watercraft prior to the invention of the rudder....

. While ancient China was home to various ship designs, including the layered and fortified tower ship

Lou chuan

Lóu chuán were a type of naval vessel, primarily a floating fortress, which has seen use in China since the Han Dynasty...

meant for calm waters of lakes and river, the junk design

Junk (ship)

(jun 船) created by the 1st century CE was China's first seaworthy sailing ship. The typical junk has a square-ended bow

Bow (ship)

The bow is a nautical term that refers to the forward part of the hull of a ship or boat, the point that is most forward when the vessel is underway. Both of the adjectives fore and forward mean towards the bow...

and stern

Stern

The stern is the rear or aft-most part of a ship or boat, technically defined as the area built up over the sternpost, extending upwards from the counter rail to the taffrail. The stern lies opposite of the bow, the foremost part of a ship. Originally, the term only referred to the aft port section...

, a flat-bottomed hull

Hull (watercraft)

A hull is the watertight body of a ship or boat. Above the hull is the superstructure and/or deckhouse, where present. The line where the hull meets the water surface is called the waterline.The structure of the hull varies depending on the vessel type...

or carvel-shaped

Carvel (boat building)

In boat building, carvel built or carvel planking is a method of constructing wooden boats and tall ships by fixing planks to a frame so that the planks butt up against each other, edge to edge, gaining support from the frame and forming a smooth hull...

hull with no keel

Keel

In boats and ships, keel can refer to either of two parts: a structural element, or a hydrodynamic element. These parts overlap. As the laying down of the keel is the initial step in construction of a ship, in British and American shipbuilding traditions the construction is dated from this event...

or sternpost

Sternpost

A sternpost is the upright structural member or post at the stern of a ship or a boat, to which are attached the transoms and the rearmost left corner part of the stern...

, and solid transverse bulkheads

Bulkhead (partition)

A bulkhead is an upright wall within the hull of a ship or within the fuselage of an airplane. Other kinds of partition elements within a ship are decks and deckheads.-Etymology:...

in the place of structural ribs

Boat building

Boat building, one of the oldest branches of engineering, is concerned with constructing the hulls of boats and, for sailboats, the masts, spars and rigging.-Parts:* Bow - the front and generally sharp end of the hull...

found in Western seacrafts. Since the Chinese junk lacked a sternpost, the rudder was attached to the back of the ship by use of either socket-and-jaw or block and tackle

Block and tackle

A block and tackle is a system of two or more pulleys with a rope or cable threaded between them, usually used to lift or pull heavy loads.The pulleys are assembled together to form blocks so that one is fixed and one moves with the load...

(which differed from the later European pintle

Pintle

A pintle is a pin or bolt, usually inserted into a gudgeon, which is used as part of a pivot or hinge.A pintle/gudgeon set is used in many spheres, for example: in sailing to hold the rudder onto the boat; in transportation a pincer-type device clamps through a lunette ring on the tongue of a...

and gudgeon

Gudgeon

A gudgeon is a circular fitting, often made of metal, which is affixed to a surface. It allows for the pivoting of another fixture. It is generally used with a pintle, which is a pin which pivots in the hole in the gudgeon. As such, a gudgeon is a simple bearing.-Winged gudgeons:A winged gudgeon...

design of the 12th century). As written by a 3rd century author, junks had for-and-aft rigs

Junk Rig

The Junk rig, also known as the Chinese lugsail and Sampan rig, is a type of sail rig in which rigid members, called battens, span the full width of the sail and extend the sail forward of the mast....

and lug sails

Lugger

A lugger is a class of boats, widely used as traditional fishing boats, particularly off the coasts of France, Scotland and England. It is a small sailing vessel with lugsails set on two or more masts and perhaps lug topsails.-Defining the rig:...

.
Although horse and ox-drawn cart

Cart

A cart is a vehicle designed for transport, using two wheels and normally pulled by one or a pair of draught animals. A handcart is pulled or pushed by one or more people...

s and spoke-wheeled chariot

Chariot

The chariot is a type of horse carriage used in both peace and war as the chief vehicle of many ancient peoples. Ox carts, proto-chariots, were built by the Proto-Indo-Europeans and also built in Mesopotamia as early as 3000 BC. The original horse chariot was a fast, light, open, two wheeled...

s had existed in China long before the Han Dynasty, it was not until the 1st century BCE that literary evidence pointed to the invention of the wheelbarrow

Wheelbarrow

, while painted murals on Han tomb walls of the 2nd century CE show the wheelbarrow in use for hauling goods. While the 'throat-and-girth' harness was still in use throughout much of the ancient world (placing an excessive amount of pressure on horses' necks), the Chinese were placing a wooden yoke across their horses' chests with traces to the chariot shaft by the 4th century BCE in the State of Chu (as seen on a Chu lacquerware

Lacquerware

Lacquerware are objects decoratively covered with lacquer. The lacquer is sometimes inlaid or carved. Lacquerware includes boxes, tableware, buttons and even coffins painted with lacquer in cultures mostly in the Eastern Hemisphere.-History:...

). By the Han Dynasty, the Chinese replaced this heavy yoke with a softer breast strap, as seen in Han stamped bricks and carved tomb relief

Relief

Relief is a sculptural technique. The term relief is from the Latin verb levo, to raise. To create a sculpture in relief is thus to give the impression that the sculpted material has been raised above the background plane...

s. In the final stage of evolution, the modern horse collar

Horse collar

A horse collar is a part of a horse harness device used to distribute load around a horse's neck and shoulders when pulling a wagon or plow. The collar often supports and pads a pair of curved metal or wood pieces, called hames, to which the traces of the harness are attached...

was invented in China by the 5th century CE, during the Northern Wei

Northern Wei

The Northern Wei Dynasty , also known as the Tuoba Wei , Later Wei , or Yuan Wei , was a dynasty which ruled northern China from 386 to 534 . It has been described as "part of an era of political turbulence and intense social and cultural change"...

period.

Weaponry and war machines

The pivot catapult

Catapult

A catapult is a device used to throw or hurl a projectile a great distance without the aid of explosive devices—particularly various types of ancient and medieval siege engines. Although the catapult has been used since ancient times, it has proven to be one of the most effective mechanisms during...

, known as the traction trebuchet

Trebuchet

A trebuchet is a siege engine that was employed in the Middle Ages. It is sometimes called a "counterweight trebuchet" or "counterpoise trebuchet" in order to distinguish it from an earlier weapon that has come to be called the "traction trebuchet", the original version with pulling men instead of...

, had existed in China since the Warring States Period

Warring States Period

(as evidenced by the Mozi
Mozi
Mozi |Lat.]] as Micius, ca. 470 BC – ca. 391 BC), original name Mo Di , was a Chinese philosopher during the Hundred Schools of Thought period . Born in Tengzhou, Shandong Province, China, he founded the school of Mohism, and argued strongly against Confucianism and Daoism...

). It was regularly used in sieges during the Han Dynasty, by both besiegers and the besieged. The most common projectile weapon used during the Han Dynasty was the small handheld, trigger-activated crossbow

History of crossbows

This history of crossbows documents the historical development and use of the crossbow.It is not clear exactly where and when the crossbow originated, but there is undoubted evidence that it was used for military purposes from the second half of the 4th century BC onwards.- Europe :The earliest...

(and to a lesser extent, the repeating crossbow

Repeating crossbow

A repeating crossbow is a crossbow where the separate actions of stringing the bow, placing the bolt and shooting it can be accomplished with a simple one-handed movement while keeping the crossbow stationary. This allows a higher rate of fire than a normal crossbow...

), first invented in China during the 6th or 5th century BCE. Although the nomadic Xiongnu

Xiongnu

were able to twist their waists slightly while horse-riding and shoot arrows at targets behind them, the official Chao Cuo

Chao Cuo

Cháo Cuò was a Chinese political advisor and official of the Han Dynasty , renowned for his intellectual capabilities and foresight in martial and political matters. Although not against the philosophy of Confucius , he was described by later Eastern Han scholars as a Legalist...

(d. 154 BCE) deemed the Chinese crossbow superior to the Xiongnu bow.
The Han Chinese also employed chemical warfare

Chemical warfare

Chemical warfare involves using the toxic properties of chemical substances as weapons. This type of warfare is distinct from Nuclear warfare and Biological warfare, which together make up NBC, the military acronym for Nuclear, Biological, and Chemical...

. In quelling a peasant revolt near Guiyang

Guiyang

Guiyang is the capital of Guizhou province of Southwest China. It is located in the centre of the province, situated on the east of the Yunnan–Guizhou Plateau, and on the north bank of the Nanming River, a branch of the Wu River. The city has an elevation of about 1,100 meters...

in 178 CE, the imperial Han forces had horse-drawn chariots carrying bellows

Bellows

that were used to pump powdered lime (calcium oxide

Calcium oxide

Calcium oxide , commonly known as quicklime or burnt lime, is a widely used chemical compound. It is a white, caustic, alkaline crystalline solid at room temperature....

) at the rebels, who were dispersed. In this same instance, they also lit incendiary

Incendiary device

Incendiary weapons, incendiary devices or incendiary bombs are bombs designed to start fires or destroy sensitive equipment using materials such as napalm, thermite, chlorine trifluoride, or white phosphorus....

rags tied to the tails of horses, so that the frightened horses would rush through the enemy lines and disrupt their formations.

To deter pursuits of marching infantry or riding cavalry, the Han Chinese made caltrop

Caltrop

A caltrop is an antipersonnel weapon made up of two or more sharp nails or spines arranged in such a manner that one of them always points upward from a stable base...

s (barbed iron balls with sharp spikes sticking out in all directions) that could be scattered on the ground and pierce the feet or hooves of those who were unaware of them.

External links

Hunan Provincial Museum (picture and description of the 2nd-century-BCE Mawangdui garrison map)
"Ceramic Models of Wells in the Han Dynasty (206 BC to AD 220), China," by Jiu J. Jiao, University of Alabama (pictures and description of Han architectural models)

The source of this article is wikipedia, the free encyclopedia. The text of this article is licensed under the GFDL.

Modern perspectives on science and technology during Han

Writing materials

Ceramics

Metallurgy

Furnaces and smelting techniques

Use of steel, iron, and bronze

Tools and methods

Alternating fields

Pit fields

Rice paddies

Literary sources and archaeological evidence

Uses of the waterwheel and water clock

Seismometer

Mathematical treatises

Innovations in the treatises

Approximations of pi

Musical tuning and theory

Astronomical observations

Han calendars

Astronomical theory

Structural engineering and public works

Materials and construction

Courtyard homes

Chang'an and Luoyang, the Han capitals

Underground tombs

Boreholes and mining shafts

Ceramic model buildings

Roads, bridges, and canals

Medicine

Cartography

Nautics and vehicles

Weaponry and war machines

See also

External links