The architecture of the Song Dynasty (960–1279) built upon the accomplishments of its predecessors, much like the subsequent dynastic periods of China. The hallmarks of Chinese architecture during the Song period were; its towering Buddhist pagodas, enormous stone and wooden bridges, its lavish tombs, and palatial architecture. Although literary works on architecture existed beforehand, during the Song Dynasty it blossomed into maturity and represents a more professional outlook, described dimensions and working materials in a concise, more organised manner. In addition to the remaining build examples, architecture in Song artwork and illustrations of architectural drawings in published books also aid modern historians in understanding the nuances of architecture originating from the Song period.
The profession of the architect, craftsman, carpenter, and structural engineer were not seen as high professions equal to the likes a Confucian scholar-officials in pre-modern China. Architectural knowledge was passed down orally for thousands of years in China, usually from craftsman fathers to their sons. However, there were also government agencies and schools for construction, building and engineering. The Song Dynasty's building manuals aided not only the various private workshops, but also the government employees enlisted as craftsmen for the central government.
The layout of ancient Chinese capitals followed the guidelines of Kao Gong Ji: a square city wall with several gates on each side and passageways for the emperor; this was no exception for the capital of the North Song Dynasty. The outer city of ancient Bianjing was built in the reign of Emperor Shenzong. The plan of Bianjing's outer city was rectangular, the length of NS sides were about 6000 m, the WE sides about 7000 m, almost square in shape. The south city wall had three gates, with Nanxun Gate at the center, Chenzhou Gate to its east and Dailou Gate to its west. The east city wall had four gates: namely Dongshui Gate (SE), Xinsong Gate, Xinchao Gate, North-East Water Gate. The west hall had four gates: Xinzheng Gate, West Water Gate, Wansheng Gate, Guzi Gate. The north wall had four gates: Chenqiao Gate at the east end, followed by Fengqiu Gate, New Wild Jujube Gate and Weizhou Gate. The outer wall was surrounded by a 30 m wide moat, called Dragon Guard River. Willow trees lined its two banks. There were turrets on top of the wall, one at every 100 steps. The four central gates at the four sides were reserved for the emperor; these gates had straight passages and only two sets of doors, while the other city gates had zigzag passages and were guarded by three sets of doors.
Song Dynasty artist Zhang Zeduan's painting Along the River During the Qingming Festival depicted the Dongshui Gate in detail, the builing on top had Song Dynasty style five ridge roof with mild slope, supported prominently by two sets of bracket(dougong) assembly, the lower level bracket assembly sat on top of the city gate and formed a wooden foundation;a top level bracket assembly supporting the roof, similar to the dougong assembly of a still standing Song Dynasty building, the Goddess Temple in Taiyuan. This method of using a lower set of bracket assembly as foundation to support superstructure was specified in Yingzhao Fashi as "pingzuo" (literally "flat base")vol 4.4
Foundation: For every square chi, apply two dan of earth; on top of it lay mixture of broken brick, tile and crushed stones, also two dan. To every 5 cun layer of earth, two men standing face to face, ram six times with pestles each man rams 3 times on a dent;then ram four times on each dent, two men again standing face to face, each rams twice on the same dent, then ram two times, each man rams one times. Following this, ram the surface with pestles or stamp with feet randomly to even out the surface. For every 5 cun thickness of earth, ram it to 3 cun; for every 3 cun of brick and stone layer, ram it to one and half cun.
All rammed earth walls in ancient China used tapering technique, ie, the bottom part of earth wall is thicker, tapering off and getting thinner and thinner. The bottom width of East Capital outer city wall was more than 34 meter, and its top width was greater than 5 m, the wall was more than 9 meters high. The tapering technique was also detailed in Li Jie's book:
Standard for city wall: For every 40 chi height, the width of the wall at the base will be increase by half of the height; the width of the top of the wall must be decreased by half the height. The width of the foundation must be the same as the width of the base of the wall. For every 7.5 chi length of wall, apply two permanent anchor posts and two crossbeams; reinforced with additional woods and straw bundles.
During the Song Dynasty, Bianjing city had three enclosures, the outer city wall, the inner city wall, and the palace at center. The inner city was rectangular, with three doors on each side.
The Palace enclosure was also rectagular with four watchtowers, one on each corner. There were four main gates, Xihua Gate at the west, Donghua Gate at the east, Gongchen Gate at the north, and Xuade Gate, also known as Duan Gate or Xuandelou at the south. Xuande Gate had five panel of doors, painted in red color and decorated with gold tacks; its walls were majestically decorated with dragon, phoenix and floating cloud patterns to match the carved beams, painted rafters and glazed tile roof. Two glazed dragons heads(called "chi wei") each biting one end of the top ridge, and tail pointing towards the sky. The symbolic function of the "chi wei" was explained in Yingzao Fashi,
There is a dragon in the East Sea, with tail(wei) similar to sparrow hawk(chi), it stirs up waves and caused rainfall, hence people put its likeness on the rooftop to prevent fire, however, they misnamed it as sparrow hawk tail (chi wei).
An image of the Xuande Gate and its dragon heads was captured vividly by Emperor Huizong of Song. One evening of 1112, Emperor Huizong saw red clouds surrounded the Xuande Gate, a flock of white cranes circling in the sky above it, and two cranes perched each on top of a rooftop dragon head, he considered that an auspicious sign, and resulted in the painting.
The boulevard south from the Xuande Gate was the Imperial Boulevard, about two hundred steps wide, with Imperial Corridor on either side; before 1112, merchants were allowed to open shops in the corridors, later banned. Two rows of black fence were placed at the center of boulevard to blocked off pedestrians and carriages. Along the inner sides of the fence, there were two rows of brick lined Imperial Water Furrow, filled with lotus. About 400 meter south from Xuande Gate, Bian River intercepted the Imperial Boulevard, a balustraded flatbed stone bridge called Zhou Bridge crossed the river. During spring and summer, mingled peach trees, plum trees, pear trees and apricot trees adorned the river banks with variety of flowers, as beautiful as brocade.This boulevard with stone bridge crossing river design was later imitated in the Forbidden City.
After the Han Dynasty (202 BC–220 AD), the idea of the Buddhist stupa entered Chinese culture, as a means to house and protect scriptural sutras. During the Southern and Northern Dynasties period, the distinct Chinese pagoda was developed, its predecessor being the tall watchtowers and towering residential apartments of the Han Dynasty (as seen through Han-era tomb models). During the Sui (581–618) and Tang (618–907) periods, Chinese pagodas were reverted from purely wooden architecture into articulated stone and brick, which could more easily survive lightning fires, arson, and avoid the natural rotting of wooden material over the ages. The earliest existent brick pagoda is the Songyue Pagoda built in 523, while a good example of a Tang era stone pagoda would be the Giant Wild Goose Pagoda constructed by 652. Although Buddhism in China had waned in influence after the late Tang period, during the Song Dynasty there were numerous Buddhist pagoda towers built. Tall Chinese pagodas were often built in the surrounding countryside instead of within the city walls, largely due to the Chinese not wanting it to compete with the cosmic-imperial authority embodied in the cities' drum-towers and gate-towers. However, there were pagodas that were built within the city's walls; an example would be the Giant Wild Goose Pagoda, built in a city ward of what was southeastern Chang'an.
The 'Iron Pagoda' of Youguo Temple in Kaifeng is an excellent example of Song-era architecture, earning its name because of the iron-grey color of the glazed-bricks forming the tower. Originally built as a wooden pagoda by the architect Yu Hao, it was struck by lightning and burned down in 1044 during the Northern Song period. In 1049 the pagoda was rebuilt as it appears today, under the order of Emperor Renzong of Song. This octagonal-base pagoda structure stands at a current height of 56.88 meters (186.56 feet tall), and with a total of 13 story levels. It's glazed tile bricks feature carved artwork of dancing figures, solemn ministers, and Buddhist themes (see Gallery below).
However, China also featured real iron-cast pagodas, such as the Iron Pagoda of Yuquan Temple (Jade Springs Temple), Dangyang, Hubei Province. Built in 1061 AD during the Northern Song, it holds a weight of 53848 kg (53 t) of cast iron, at a standing height of 21.28 m (70 ft tall).[16 ] In mock and model after the roofing tiles of actual wooden, stone, or brick pagodas of the Song period, this iron pagoda also features delicate sloping eaves, and has an octagonal-shaped base.
The Liuhe Pagoda, or Six Harmonies Pagoda, is another famous Song-era work of pagoda architecture. It is located in the Southern Song capital of Hangzhou, Zhejiang Province, China, at the foot of the Yuelun Hill facing the Qiantang River. Although the original was destroyed in 1121, the current tower was erected in 1156, fully restored by 1165. It stands at a height of 59.89 m (196 ft tall), constructed from a red-brick frame with 13 layers of wooden eaves. The Liuhe Pagoda, being of considerable size and stature, served as a permanent lighthouse from nearly its beginning, to aid sailors in seeking anchorage for their ships at night (as described in the Hangzhou Fu Zhi). During the Southern Song period, it was one of the most renowned piece of architecture in the capital city.
The Twin Pagodas of Kaiyuan Temple in Quanzhou are also renowned within China. The first pagoda, the Zhenguo Pagoda, was originally built of wood during the Xiantong period (860–873). Its twin structure, the Renshou Pagoda (also originally constructed with wood) was built in 916 AD. After being destroyed several times by fire and other calamity, the present Renshou Pagoda was built of stone in 1228 AD, while its twin structure of the Zhenguo Pagoda was also built of stone in 1238 AD (sponsored by a Buddhist monk known as Bengong). The Renshou Pagoda is 44.6 m tall, while the Zhenguo Pagoda is slightly taller, at a height of 48.24 m tall.
The Zhengjue Temple Pagoda in Pengxian County of Sichuan Province (near Chengdu) is a brick pagoda that was built between 1023 and 1026 AD, according to its inscriptions along the first story of the pagoda. The pagoda has a square base on a sumeru pedestal, stands at thirteen stories in a total of 28 m in height, and its multiple layers of eaves are similar in style to the earlier Tang Dynasty pagodas found in Chang'an, the Giant Wild Goose Pagoda and Small Wild Goose Pagoda.
The Liao Dynasty to the north was also famous for its Buddhist pagoda architecture. Although many brick and stone pagodas, and brick-stone/wood hybrid pagodas built beforehand have survived the ages, the tallest and oldest fully-wooden pagoda still standing in China was of Liao-Khitan making, the Pagoda of Fogong Temple (also called Sakyamuni Pagoda). Located in Ying County of Shanxi Province, the octogonal-base pagoda was built in 1056 AD, as a crowning architectural masterpiece of the Fugong Temple. The pagoda stands at a height of 67.13 m (220.18 ft) tall, making it taller than both the Iron Pagoda and the Liuhe Pagoda of the Song Dynasty. The pagoda also features just under sixty different kinds of bracket arms in its construction. The pagoda was built in a similar style to the Liuhe Pagoda, with its delicate wooden eaves and curving tiles, and along with the other pagodas it is a site of tourist attraction in modern times. Apparently, the pagoda was built by Emperor Daozong of Liao (Hongji) at the site of his grandmother's family home. The pagoda reached such fame that it was simply nicknamed the "Mu-ta" (Timber Pagoda) in China. While the Yingxian Pagoda is the oldest existent fully-wooden pagoda in China, the oldest-existent fully-wooden building in China is the main temple hall at Nanchan Monastery of Mount Wutai, Shanxi, built in 782 during the Tang Dynasty (it is a common misconception that the larger East Hall of nearby Foguang Temple, built in 857, is the oldest existent Tang era wooden building).
Wood-and-brick hybrid pagodas were also built, such as the 42 m (137 ft) tall Lingxiao Pagoda of 1045. The first four floors of this octagonal pagoda are brick (with wooden eaves), while the 5th floor up is entirely made of wood. Even fully brick and stone pagodas featured architectural elements that were typical of wooden Chinese buildings, such as the Pizhi Pagoda built from 1056 to 1063, which features the typical dougong brackets of wooden architecture that hold up pent, shingled roofs and tiers. Both of these pagodas feature interior staircases, although the staircase for the Lingxiao Pagoda only reaches the fourth floor, and the Pizhi Pagoda's interior staircase only reaches the fifth floor. However, the Pizhi Pagoda features winding exterior steps which allow one to visit the top ninth floor where the iron steeple is located.
Although the Pagoda of Fogong Temple is the tallest existent wooden pagoda, the tallest existent Chinese pagoda of the pre-modern age is the Liaodi Pagoda. Completed in the year 1055, it stands at a height of 84 m (275 ft) tall, with an octagonal base on a large platform. It surpasses the height of the 69 m (227 ft) tall Qianxun Pagoda, which was earlier the tallest pagoda in China when built in the 9th century by the Kingdom of Dali. Although Liaodi served its religious purpose as a Buddhist landmark in the Kaiyuan Monastery of Ding County, Hebei province, with its great height it served another valuable purpose as a military watchtower used to spot enemy movements of the Khitan Liao Dynasty. Besides watchtowers, towers could also serve as large astronomical observatories. This includes the Gaocheng Astronomical Observatory built in 1276 AD, still standing today.
The Temple of the Saintly Mother (圣母殿) and Hall of Sacrifice in the Jin Temple (晋祠) at southeast suburb of Taiyuan City, Shanxi province are two prime examples of remaining early Song Dynasty architecture. The Temple of the Saintly Mother is the main building of Jin Temple, it was first built in the period beween 1023 1032 and renovated in 1102. It has a double-eaved roof with nine ridges, two dragon heads with wide open jaw biting two ends of the main ridge. The roof is supported by massive functional dougong corresponding to the drawings in Yingzao Fashi. The eave lines of the Temple of the Saintly Mother are slightly curved upward at both end, a characteristic of Song Dynasty building, two central columns of its facade are shortest, the column height increases progressively further way from the center. The building has a porch around it, it is the sole example of such kind of architecture. The front columns are wrapped around with curling dragons. The cross shape bridge in leading to the Goddess Temple is a unique feature of the temple site.
The Trinity Hall of Xuan Miao Temple (玄妙观) in the heart of Suzhou city is another example of Song architecture. It was established as a National Heritage Site item 2.22 of Song Dynasty architecture classification in 1982 by the Chinese Government.
Bridges over waterways had been known in China since the ancient Zhou Dynasty, and even floating pontoon bridges were mentioned from the Zhou period (Song era pontoon bridges include the Dongjin Bridge, 400 meters long, which is still seen today). Bridges of the Zhou Dynasty were often built entirely of wood, while some featured stone piers. The first bridge in China to be built entirely of stone was an arch bridge of 135 AD, spanning a transport canal in the Eastern Han capital of Luoyang.[29 ] With brilliant engineers such as Li Chun of the Sui period, grand bridge-works like the Zhaozhou Bridge of 605 AD were built. In terms of global history, this bridge is famous for being the world's first fully stone open-spandrel stone segmental arch bridge (in Europe, the bridge of Roman Emperor Trajan over the Danube featured wooden-built open-spandrel segmental arches on stone piers (Trajan's Bridge), while the first purely-stone segmental arch bridges date from the 1st century BC such as the Ponte San Lorenzo or, later, the Pont des Marchands. The Zhaozhou Bridge would continue to influence later Chinese bridges, such as the similar Yongtong Bridge near Zhaoxian in Hebei. The Yongtong Bridge is a 26 m (85 ft) long stone segmental-arch bridge built in 1130 by the Song structural engineer Pou Qianer.[31 ]
During the Song Dynasty, bridge construction reached an even greater height of sophistication and grand extent. There were large trestle-structure bridges built during the Song, like the one built by Zhang Zhongyan in 1158 AD. There were also large bridges built entirely of stone, such as the Ba Zi Bridge of Shaoxing, built in 1256 AD, which still stands today. Bridges with stylish Chinese pavilions crowning their central spans were often featured in painted artwork, like the landscape paintings of Xia Gui (1195–1224). There were also long roof-covered corridor bridges built, such as the 12th century Rainbow Bridge in Wuyuan, Jiangxi province, which has wide stone-base piers and a top-level wooden frame. While he was an administrator for Hangzhou, the famous Chinese poet, travel writer, and government official Su Shi (1037–1101) had a large pedestrian causeway built across the West Lake, which still bears his name: sudi (蘇堤). In 1221, the Daoist traveler Qiu Changchun once visited Genghis Khan in Samarkand, describing various Chinese bridges in his travels there through the Tian Shan Mountains, east of Kuldja. The historian Joseph Needham quotes him as saying:
[The road had] 'no less than 48 timber bridges of such width that two carts can drive over them side by side'. It had been built by Chang Jung [Zhang Rong] and the other engineers of the Chagatai some years before. The wooden trestles of Chinese bridges from the -3rd century (BC) onwards were no doubt similar to those supposed to have been employed in Julius Caesar's bridge of -55 (BC) across the Rhine, or drawn by Leonardo, or found in use in Africa. But where in +13th century (AD) Europe could a two-lane highway like Chang Jung's have been found?
In medieval-era Fujian Province, there were enormous beam bridges built during the Song Dynasty. Some of these bridges were built at a length of 1219.2 m (4,000 ft), with the length of their individual spans of up to 22.33 m (70 ft) in length, and the construction of which necessitated the moving of massive stones that weighed 203200 kg (200 t). Unfortunately, no names of the engineers of the Fujian bridges were recorded or featured on inscriptions of the bridges. The only names featured were merely the names of the Song-era local officials that sponsored them and gave oversight of their construction and repair. However, the historian Joseph Needham points out that there might have been an engineering school of Fujian headed by a prominent engineer of the time known as Cai Xiang (1012–1067). Cai was a noted scholar, an author of books on lichi fruit and tea, and who had risen to the seat of a governmental prefect in Fujian. Near Quanzhou, Cai Xiang planned and supervised the construction of the large Wanan Bridge (once called the Luoyang Bridge, constructed from 1053–1059 AD), a stone bridge similar to other bridges found in Fujian. The bridge still stands today, and features ship-like piers that reduce the amount of rapid river water friction. Its dimensions are 731 m (2,398 ft) in length, 5 m (16 ft) in width, and 7 m (22 ft) in height.
Located southwest of Gongyi city in Gongxian County in Henan province, the large tombs of the Northern Song Dynasty include a total of some 1,000 tombs, including individual tombs for Song emperors, empresses, princes, princesses, consorts, and extended family. The size of the complex has an area of approximately 7 km (4.3 miles) running east to west by 8 km (5 miles) running north to south. Construction on the complex began in 963 AD, during the reign of the first Song ruler Emperor Taizu of Song, whose father is also buried at the site. The only Northern Song emperors not buried there are Emperor Huizong of Song and Emperor Qinzong of Song, who died in captivity after the Jurchen invasion of northern China in 1127. Lining the avenues of the tomb complex are hundreds of Song Dynasty sculptures and statues of tigers, rams, lions, horse and groom, horned beasts and mythical creatures, government officials, military generals, foreign ambassadors, and others featured in an enormous display of Song era artwork.
The layout and style of the Song tombs resemble those found in the contemporary Tangut kingdom of the Western Xia, which also had an auxiliary burial site associated with each tomb. At the center of each burial site in the complex is a truncated pyramidal tomb, each tomb once guarded by a four-walled enclosure with four centered gates and four corner towers. About 100 km from Gongxian is the well-excavated Baisha Tomb, a grand example of Song era subterranean tomb architecture, with "elaborate facsimiles in brick of Chinese timber frame construction, from door lintels to pillars and pedestals to bracket sets, that adorn interior walls." The Baisha Tomb had two large separated chambers with cone-shaped ceilings, and leading down to the entrance doors of the subterranean tomb is a large stair case.
During the Song Dynasty, previous works on architecture were brought to more sophisticated levels of description, such as the Yili Shigong, written by Li Ruogui in 1193 AD. One of the most definitive works, however, was the earlier Mu Jing ('Timberwork Manual'), ascribed to the Master-Carpenter (Du Liao Jiang) known as Yu Hao, written sometime between 965 to 995. Yu Hao was responsible for the construction of an elegant wooden pagoda tower in Kaifeng, one that unfortunately was burnt down by lightning and replaced by the brick Iron Pagoda soon after. In his time, books on architecture were still considered a lowly scholarly achievement since it was associated with a middle-class craft, therefore it was not even recorded in the official court bibliography. Although the Timberwork Manual was lost to history, the scientist and statesman Shen Kuo wrote of his work extensively in his Dream Pool Essays of 1088, praising the Timberwork Manual as a work of architectural genius, and that no one in his own time could reproduce such a work. However, several years later, there was such a man, known as Li Jie (李誡; 1065–1110), who wrote the Yingzao Fashi ('Treatise on Architectural Methods' or 'State Building Standards'). Although others existed before, such as the Yingshan Ling (National Building Law) of the early Tang Dynasty (618–907), Li's book is the oldest existent technical manual on Chinese architecture to have survived in full.
In his youth, Li Jie was well educated, since his father had been the Minister of Revenue at the Song court. Besides his later work on architecture, Li Jie also published books on geography, history, and philology, and was also a painter. When Shen Kuo was in office, Li Jie was an up-and-coming official in the Bureau of Imperial Sacrifices, and by 1092 he had been moved to the Directorate of Buildings and Construction, where he showed much promise as an architect. He revised many older treatises on architecture from 1097 until 1100. His written work was complete in 1100, and he presented his work to Emperor Zhezong of Song in his last year of reign. His successor Emperor Huizong of Song had Li's book officially published three years later in 1103, so that it could benefit foremen, architects, and literate craftsmen. His book was aimed not only at providing standard regulations for the engineering agencies of the central government, but also the many workshops and artisan families throughout China who could benefit from using a well-written government manual on building practices. With his book becoming a noted success, Li Jie was promoted by Huizong as the Director of Palace Buildings. Thereafter Li became well-known for the oversight in construction of administrative offices, palace apartments, gates and gate-towers, the ancestral temple of the Song Dynasty, along with numerous Buddhist temples. In 1145 a second edition of Li's book was published by Wang Huan.
Li's Yingzao Fashi included building codes and regulations, accounting information, materials used in construction, and classification of different crafts. Written in 34 chapters, the book outlined units of measurement, the construction of moats and fortifications, stonework, greater woodwork, lesser woodwork, including specifications (and illustration) for making bracketing units with inclined arms and joints for columns and beams, wood carving, turning and drilling, sawing, bamboo work, tiling, wall building, painting and decoration, recipes for decorative paints, glazes, and coatings, mixture proportions for mortars in masonry, brickwork, glazed tile making, and provided drawn illustrations of all these practices and standards. His book outlined structural carpentry in great detail, providing standard dimensional measurements for all components used. In this he developed a standard 8-grade system of different size timber elements known as the cai-fen system of units, which could be universally applied in buildings. About 8% of Li Jie's book took material from preexisting written material on architecture, while the majority of the book documented the inherited traditions of craftsmen and architects. Li's book provided a full glossary of technical terms that included mathematical formulae, building proportions and construction, and incorporated topography in estimations on how to build on different sites. He also estimated the monetary costs of hiring laborers of different skill levels and crafts, on the basis of a day's work, the materials needed, and the seasons employed in.
In 1919, Zhu Qiqian was so intrigued by reading an 1145 AD Ding's handcopy of the Yingzao Fashi at the Nanjing Provincial Library, a photolithographic edition in the same year was published by the Commercial Press (known as Ding edition); and he established the Chinese Architecture Institute(Zhongguo Yingzao Xueshe). Soon after, half page fragment of a Song Dynasty edition were discovered in Qing Dynasty court documents; Tao Xian then cross checked the Ding edition with a Wenyuan Chamber edition and a Jiang Library edition, redrawn nearly 100 original line drawings into color plates based on Li's notes, compiled according to the style of Song fragment and published a deluxe edition in 1925 (later referred to as Tao edition). The Chinese Architecture Institute began studying the book in greater detail. The 1925 publication spurred worldwide interest in Chinese architecture, with French author Paul Demièville, British scholar W. Perceval Yetts, and Japanese scholar Takuichi Takeshima. In 1932 another Song Dynasty handcopy edition of Yingzao Fashi was discovered in the Forbidden City (referred to as Forbidden City edition). Liang Sicheng and Liu Dunzhen of the Institute double-checked the Tao edition against the Forbidden City edition, recovered important omissions of the Tao edition and was printed 1932. Since 1925, Liang Sicheng has spent nearly forty years in the research of Yingzao Fashi, as the result of his work, Annotated Yingzao Fashi complete with modern engineering diagrams was published posthumously by Qinghua University in 1980, (later included as vol 7 of Liang's collected works 
In his Dream Pool Essays of 1088, the Song scientist and statesman Shen Kuo was one to praise the architectural and structural written work of Yu Hao, who once had a marvellous wooden Chinese pagoda built at the Song capital of Kaifeng. Below is a passage from one of Shen's books outlining the basics contained in Yu's 10th century work on early Song-era architecture:
In the first quote, Shen Kuo describes a scene were Yu Hao gives advice to another artisan architect about slanting struts for diagonal wind bracing:
When Mr. Qian (Weiyan) was Governor of the two Zhejiang provinces, he authorized the building of a wooden pagoda at the Fantian Si (Brahma-Heaven Temple) in Hangzhou with a design of twice three stories. While it was under construction General Qian went up to the top and was worried because it swayed a little. But the Master Builder explained that as the tiles had not yet been put on, the upper part was still rather light, hence the effect. So then they put on all the tiles, but the sway continued as before. Being at a loss what to do, he privately sent his wife to see the wife of Yu Hao with a present of golden hair pins, and enquire about the cause of the motion. (Yu) Hao laughed and said: 'That's easy, just fit in struts to settle the work, fixed with (iron) nails, and it will not move any more.' The Master Builder followed his advice, and the tower stood quite firm. This is because the nailed struts filled in and bound together (all the members) up and down so that the six planes (above and below, front and back, left and right) were mutually linked like the cage of the thorax. Although people might walk on the struts, the six planes grasped and supported each other, so naturally there could be no more motion. Everybody acknowledged the expertise thus shown.
In this next quote, Shen Kuo describes the dimensions and types of architecture outlined in Yu Hao's book:
Methods of building construction are described in the Timberwork Manual, which, some say, was written by Yu Hao. (According to that book), buildings have three basic units of proportion, what is above the cross-beams follows the Upperwork Unit, what is above the ground floor follows the Middlework Unit, and everything below that (platforms, foundations, paving, etc.) follows the Lowerwork Unit. The length of the cross-beams will naturally govern the lengths of the uppermost cross-beams as well as the rafters, etc. Thus for a (main) cross-beam of (8 ft) length, an uppermost cross-beam of (3.5 ft) length will be needed. (The proportions are maintained) in larger and smaller halls. This (2/28) is the Upperwork Unit. Similarly, the dimensions of the foundations must match the dimensions of the columns to be used, as also those of the (side-) rafters, etc. For example, a column (11 ft) high will need a platform (4.5 ft) high. So also for all the other components, corbelled brackets, projecting rafters, other rafters, all have their fixed proportions. All these follow the Middlework Unit (2/24). Now below of ramps (and steps) there are three kinds, steep, easy-going, and intermediate. In places these gradients are based upon a unit derived from the imperial litters. Steep ramps are ramps for ascending which the leading and trailing bearers have to extend their arms fully down and up respectively (ratio 3/35). Easy-going ramps are those for which the leaders use elbow length and the trailers shoulder height (ratio 1/38); intermediate ones are negotiated by the leaders with down-stretched arms and trailers at shoulder height (ratio 2/18). These are the Lowerwork Units. The book (of Yu Hao) had three chapters. But builders in recent years have become much more precise and skillful than formerly. Thus for some time past the old Timberwork Manual has fallen out of use. But (unfortunately) there is hardly anybody capable of writing a new one. To do that would be a masterpiece in itself!
Games in the Jinming Pool, a painting by Zhang Zerui depicting Kaifeng, the Northern Song capital.
A Kaifeng palace rooftop visited by cranes, by Emperor Huizong of Song (r. 1100–1126)
Expecting Guests, by Ma Lin, c. 1250.
Transverse corbel brackets, Yingzao Fashi (1103)
Bracket and cantilever arms, Yingzao Fashi (1103)
Northern Song era water-powered grain mill
Same painting by Zhang Zeduan, wider scene of urban buildings and a large gatehouse to the right.