Gaoping Kaihua Temple "Li Jizi" image exploration

Gaoping Kaihua Temple "Li Jizi" image exploration

The Vertical Weaving Machine Image in the Murals ofKaihua Temple,Gaoping

Dialectics of Nature Newsletter 2021.02 Yi Bao/YI Bao Gao Ce/GAO Ce Shi Honglei/SHI Honglei

(Institute of History of Science and Technology, Shanxi University)

(Institute for History of Science and Technology,Shanxi University,Taiyuan,Shanxi,030006)

Abstract: The mural painting of Gaoping Kaihua Temple has a "vertical machine" weaving map, which has become a single vertical loom with pedals in the Song Dynasty. Its shape is similar to the "standing machine" contained in Xue Jingshi's "Ziren Relic System" in the late Jin Dynasty and early Yuan Dynasty, and the two images have superb realistic painting techniques and their authenticity is high. From the analysis of the structure and assembly process of the loom, the loom and the Xue's "vertical machine" are not the same in many parts such as the central shaft and the horse head, and the process of its distribution is quite different. These two images also show the characteristics of regional tools in the development of the family workshop weaving industry in southern Jinnan and southeastern Jin, and are representatives of small looms in the north during the Song and Yuan dynasties, and have high image historical value.

Zhao Feng of the China Silk Museum's article "Research on Pedal Vertical Machine", which collects many sources to restore Xue's loom and analyzes its assembly structure and working principle in detail, is the most valuable result in the research on this loom in the past ten years. [1] Prior to this, the German textile engineer Dieter Kuhn published a monograph in 1977 on multiple looms in Die Webstühle des Tzu-jen i-chih aus der Yüan-Zeit, with the "vertical machine" illustrated and illustrated each component in detail. [2] Chen Weiji's "History of Chinese Textile Science and Technology" lists the "vertical loom" section to analyze its working principle, and explains the current remaining "vertical machine" image. [3] Wang Jinyu of the Dunhuang Research Institute studied the Tang Dynasty "Lijizi" in Dunhuang Cave 6, which is the oldest image at present,[4] and Dr. Xu Yanhong of the Institute of Science and Technology History of Shanxi University also has a paper related to the "Lijizi" of Kaihua Temple. [5] From the analysis of the research content, Zhao Feng referred to the images of Gaoping Kaihua Temple when restoring Xue's "Standing Machine", which was mainly reflected in the connecting rods and Tengzi and other institutions that were not recorded in the "Ziren Relic System", and the analysis of the restored looms was based on the mural images of the Kaihua Temple. The most important contribution of Zhao Feng's research is not only to check for omissions and fill in the gaps, but also to the true reproduction of Xue's "vertical machine". In this paper, the murals of Kaihua Temple are reinterpreted on the image, and the details use macro photography to obtain clearer details of the loom, which also provides excellent basic conditions for the restoration of the image of the mural loom. However, an analysis of the details of this Northern Song mural shows that this image first belongs to the middle of the Northern Song Dynasty in chronology, and it is also the peak of genre painting, which predates the "Qingming Upper River Map" and is in the embryonic stage of science. Images exhibit the characteristics of sketchbooks, so they depict as realistic as ancient cartographic images. Through the analogy with Zhao Feng's restored loom, it was found that many of the structures in the mural were inconsistent with Xue's image, and thus, with the help of Zhao's research foundation, the assembly process of this image was reconstructed. It is found that there are large differences in the assembly of the big five wood, palm teng wood and hanging fish, resulting in the separation process and the synthesis process has also changed, the most important thing is that Xue Shi adopted a complete wooden structure hard connection transmission mode, and the Kaihua Temple mural standing machine is a wood structure and flexible shaft lever combined with the linkage mode of auxiliary synthesis and opening exchange, this structure is not recorded by Xue Shi, but also a new assembly style of "standing machine", belonging to the Northern Song Dynasty "vertical loom". The reinterpretation of this figure can reposition the evolution of this vertical loom in the northern Song and Yuan dynasties. For a long time, this loom image is an important evidence of the record of Lu ze sang silkworm weaving in ancient times, but due to insufficient image excavation, it has also led to a misreading of the related weaving technology in the north, and it is of great significance to restore this Northern Song Dynasty woodworking weaving machinery through the combing and restoration of "stripping and stripping cocoons".

First, the difference between the East and the West of the "vertical loom" image

1. European "vertical loom" image examination

The key to the development of looms lies in the continuous improvement of the efficiency of the "cloth" process, from the process of the overlapping of the organization of warp and weft yarn on the loom, until now the application of this basic principle has never changed. The earliest loom is the "waist machine" and "vertical machine" two types, in the subsequent evolution process, the loom is also along these two basic forms of development, waist machine to the horizontal loom development, and the warp vertical weaving of the vertical machine in the opening, transmission, reel, warp several major aspects of mechanical improvement.

In South Africa, where the original looms in the world are well preserved, there are seven types of original looms: 1. The Vertical Mat Loom;

2. The Horizontal FixedHedle Loom; 3. The Vertical Cotton Loom; 4. The Horizontal Narrow Band Treadle Loom; 5. The Pit Treadle Loom; 6. Mediterranean or Asian Pedal Loom (The Mediterranean or Asiatic Treadle Loom; 7. The "Carton" Loom. 1, 3 and 6 of them all belong to vertical looms. ([6], p.28) where the vertical mat loom (Fig. 1) is a loom developed from the braided frame in the early days when the warp thread was tied to the top of the loom for operation (fig. 1, top left). Obviously, this weaving method is very limited, especially in terms of continuous weaving technology. This image began to be drawn in Europe in the nineteenth century, and the earliest image of the "vertical loom" came from an illustrated book in the Vatican Library of the Aeneid (figure 1 below), which is believed to have appeared in the fourth century and was later published by the Vatican in the book Overgil in 1741, and this "vertical loom" already had the process of weaving from the bottom. There is also a class of specialized vertical looms known as "warp looms" recorded by Johnes Robneus (fig. 1, top right), ([1], pp. 120-122), but some scholars have proposed that this loom is a fiction, in the expression of the image, although this loom also has a pedal function, but mainly by stepping on heavy objects to adjust the warp tightness, so it is not used to open the operation. From the perspective of population migration, African looms use fibers such as Lafia palm leaves and sugarcane skins in raw materials, and the "vertical loom" of European origin uses cotton yarn and wool, and the use of materials is obviously the key to promoting the evolution of independent regions of looms. Although accurate "mechanical drawings" cannot be obtained from the looms drawn by these artists, they do retain the sample display of vertical looms in different regions.

2. The occurrence of silkworm technology and "vertical loom" in northern China

If from an archaeological point of view, the spread of bronze and faience in the northern hemisphere in the similar latitudes is one of the characteristics of human migration, and weaving technology should have a similar path. During the Han Dynasty, China's silk weaving technology became the most advanced technology in Eurasia, which does not show that weaving tools are completely native, but proves that China's understanding of fabrics since ancient times is "outstanding", which also continuously promotes the development of weaving tools. From the half cocoon found by Li Ji in Xiyin Village, Xia County, Jinnan, and the belief in the "Ancestors" distributed in the area, it can be seen that the loess plateau has begun in the Neolithic Age and has been passed down in an orderly manner. It is true that this is not due to the geographical environment conditions of Shanxi, but precisely the phenological conditions of these two mountains and rivers, which provide excellent conditions for the preservation of related sites.

Since the Han Dynasty, silk has been China's most important diplomatic lever and a luxury for Goods to Europe and Asia. This also means that the Silkworm Industry and Textile Handicraft Industry in China began in the Han Dynasty and became the main means of trade for the country to obtain goods and silver from other Countries in Eurasia. From a geographical point of view, the "Mediterranean" dominated by Greece has developed the most exquisite handicraft due to good phenological conditions, but silk has become their blind spot in the textile industry, which is also an important chip for China to form trade.

The overlap of the cultivation and weaving of Chinese farming culture with the state system is also the key to the amazing improvement of this technology in the East Asian continental plate. More than two thousand years ago, it almost became a monopoly industry, which also made the technical secrecy of China's mulberry silkworm industry and the prohibition of the export of original silkworm species a thesis, but in fact there is no actual evidence, but many scholars have inferred according to the "clues" of ancient books. Zou Jingheng commented on the theory of "forbidden women without view" in the Encyclopedia Britannica and the "Ritual Record of the Moon Order", and Stein's misinterpretation of the princess in the "Records of the Western Regions of the Tang Dynasty" with silkworms into Khotan, negating the exclusivity and prohibition of sericulture technology in ancient China, and reaffirming the conclusion that the silkworm industry originated in Shandong and Shanxi. ([7], pp. 236-245) If there is no administrative means to interfere in the spread of sericulture, then the chinese silk weaving technology and maintain a long-term advantage, which is naturally inseparable from the development of looms, the sequence of Chinese looms is very complete, in the Han Dynasty has been jacquard technology "unique in the world", and "household weaving" is also an important civil guarantee to promote the development of looms and silkworm industry in the local area. It is precisely this intensive and high degree of application that enables its advanced nature to be guaranteed for a long time, and it is precisely because China continues to gain advantages in foreign trade through silk trade. At the same time, the "country based on agriculture" has also developed the silkworm industry and the harvest together, and this advantage has risen to the level of national strategy, and "heavy agriculture and heavy mulberry" has become the basis for the governance of every imperial ruler. Since the silk weaving industry can bring huge profits economically, therefore,

All the dynasties have been "the same currency", and even the court rewards have used this as a hierarchical reference. The scale of the textile industry has made the increment of successive generations. At the beginning of the Song Dynasty, due to the increase in population and the gap in land, the economy entered a new growth model. The need for business considerations and survival makes the world's "home textile thread, household loom", weaving as an essential survival skill for families. The imperial power was also repeating the decree of "persuading the peasants to persuade the sang", and the "cultivation and weaving map" came into being, which became an important reason for the secularization of Chinese painting images.

3. Chinese "vertical loom" image examination

Since the beginning of the Han Dynasty, horizontal looms and large jacquard machines have been very common, and in the Tang Dynasty, there has been a "vertical machine" with simpler mechanical properties. Dunhuang testament "Pure Land Temple Physical Objects and Other Goods In and Out of the Account" has a record of the "Standing Machine", and there are images of such spinning wheels in the "Huayan Jingchang" of Mogao Caves 6 and 98 caves. ([3], p.101) However, the structure of these two diagrams is too simple to have the reference value of restoring the "vertical machine". In contrast, the "Standing Machine" of The Kaihua Temple in Gaoping, Shanxi, is extremely accurate in structure and shape. From the Tang Dynasty to the Song Dynasty, there was an extreme disparity in the modeling characteristics of the mural images, for the following reasons: 1. The Tang Dynasty as the earliest period of the current vertical machine should be the embryonic stage, therefore, the incompleteness in the structural performance is its stage evolution form; 2. The era difference in painting style, although the Tang Dynasty has reached a certain height in plastic arts, the portrayal of custom images is particularly insufficient compared to the Northern Song Dynasty, and the examination of image details and the rigorous "paraphrasing" are the ultimate in the painting language of the Song Dynasty. This is also the characteristic of the "standing machine map" of Kaihua Temple that can transcend the image art of Dunhuang murals.

This loom is mainly used to weave cotton and silk fabrics, that is, to weave "simple tissue" textiles, including plain, twill and forging tissues, from the perspective of tissue structure, this loom in the weaving process due to yarn twisting, color, density can obtain different surfaces of fabric. The change of the internal structure is one of the decisive factors in the intrinsic physical properties of the fabric. Plain weaved tissue has the characteristics of dense weaving point, high strength, tear resistance and high flatness. This also means that the fabric is durable and has a large yield. The "Standing Machine" in the kaihua temple mural is a wooden loom that weaves this kind of plain weave, but judging from the depiction characteristics of the warp on the screen, it is speculated that it is white silk. The kaihua temple loom in the art of painting has the realistic style of northern Song Dynasty painting, and the content of the loom belongs to the content of the "Prince Asks weaving" section of the "Great Convenience Reward". "When I went forward little, I saw that men and women were weaving together, pouring back and forth, tired and hard, and the prince asked: "What is this thing to do", and replied left and right, the prince, these people and so on, weave all kinds of clothes, to cover shame, shade the five shapes, this is also a labor is not one. ([8], p. 53) This sutra is not derived from the tianzhu translation, but is based on the collection of many Buddhist texts and confucianism, which is a typical Buddhist "apocrypha", and the prevalence of this sutra during the Northern Song Dynasty illustrates the accelerated integration of the concept of loyalty and filial piety and Buddhist teachings, which is the "world entry view" chosen by Chinese Buddhism. It depicts Prince Zentomo seeing the suffering of weaving and asking questions and answers with his entourage, although the scene of the woman sitting in front of the vertical machine in the mural appears beautiful, it actually represents Buddhism's compassion for human suffering, which also shows the hardships of weaving work. Viewed from the outside of the loom, the biggest feature is to save space, the loom in the mural is only placed in a simple shack, which is a typical semi-outdoor operation, and the area is only about 2 square meters according to the estimated scene space. According to the volume, the general small horizontal machine also needs 4-5 square meters of space, this kind of vertical machine is obviously very space-saving, but also save wood, which may be the reason why it began to gradually popularize in the Tang Dynasty.

Judging from the current research results, the research of "Li Jizi" is mainly based on Xue Jingshi's "Ziren Relic System" in the literature as a reference. As a book of woodworking techniques, this book was included in the Yongle Canon and circulated. ([9], p. 80) In his 1977 book The Ziren Legacy, Kuhn systematically discussed the "Hua Jizi", "Vertical Machine", "Luo Ji", and "Small Cloth Lying Machine" in it, and cartographically restored each loom. [2]

Zhao Feng's thesis "Research on pedal vertical machines" comprehensively examines the vertical machines of various eras, especially based on the technical restoration of the "Ziren Relic System" and the "Standing Machine" of Kaihua Temple, so that this long-lost thousand-year-old loom can be reproduced in the human world. According to the records of the "Ziren Relic System", Zhao Feng reclassified 29 of them, and completed the three important components missing in the book, and reclassified them into 15 new structures, which is based on the classification method of modern weaving science. ([1], p. 147) The only regret is that due to language problems, although it is pointed out that Kuhn copied the drawing model and the actual gap, it does not point out the specific problem. The above three can be said to be the founders of the basic research of China's "vertical loom", and subsequent writings have been born from this. It is worth mentioning that these researchers have a deep background in textile machinery engineering, so the focus of their research is very rigorous from cartography to the logical derivation of mechanical structure operation. The above research is based on the "Zi Ren Relic System" as a reference. The problem is that the five images currently existing in the Standing Machine are by Tang and Yuan, which are very comprehensive in the development sequence, but the woodworking structure and manufacturing technology are not exactly the same, and it is not enough for researchers to use the "Standing Machine" image of the "Zi Ren Relic" as the main reference, therefore, this paper will use the "Standing Machine" of the Kaihua Temple as another main reference for derivation and restoration, which belongs to the lateral echo research, and the historical value of the image is excavated in depth.

Second, the "Zi ren relics system" and the Kaihua Temple "Li Jizi" fuselage structure comparison

From the perspective of iconography, the "standing loom" is preserved in the ancient images of Dunhuang murals, the murals of Kaihua Temple (figure 2 left), the illustration of the "Ziren Relic System" (figure 2 right), and the Ming Dynasty long scroll "Palace Silkworm Map" (figure 3). Modern images include two restorations of Kuhn (left in Figure 4) and Zhao Feng (right in Figure 4). These images are not identical, or even far apart. In order to better understand its working principle and structural genus, this paper divides the loom into four major parts for image analysis, 1. fuselage structure; 2. pedal transmission; 3. warp scroll; 4. wefting device.

1. The type of "vertical machine" fuselage structure support

The fuselage is the first part to be described, the "Ziren Relic" cloud: "The fuselage is five feet five inches to eight inches long, two inches wide in diameter, two inches in width, two inches in thickness, and three feet and two inches in width", ([9], p.79) In the illustration, the fuselage is a lower bracket with a leg support, kuhn and Zhao Feng also adopt this structure, but Kaihua Temple is double rear support above the fuselage, and the side is tied with bamboo poles in many places to stabilize the roof (figure 5 below), and the "Palace Silkworm Diagram" uses the frame to connect the frame with the bench to form a frame support. (Fig. 6) Compared with the horizontal machine, the vertical loom obviously does not have an advantage in the stability of operation, so various types of reinforcement according to different loom sizes can make up for some of the deficiencies. This system is called "making feet on the body" in the "Ziren Legacy System", that is, the height of the foot is determined by the width and size of the fuselage. ([9], p.83) From the overall design, it seems that the Kaihua Temple fuselage design lacks front support, and the actual operation process because all the operations are in front, and the weight of the vertical weft line itself or the gravity of the weft will cause the frame to tilt forward, as if this is a carpentry defect. However, if we go deep into the exploration of weaving materials, we can find that this vertical loom is to produce blankets, felt and other fabrics in the initial stage, the Tang Dynasty set up a special carpet weaving workshop, and the Yuan Dynasty increased the output of such fabrics. ([3], p.226) Gaoping has been the site of the silkworm since ancient times, and the only depiction of a white warp "vertical loom" in the picture, shanxi at that time did not have cotton weaving, so weaving narrow silk objects did not produce greater gravity, and the back brace design was sufficient. From the overall fuselage support file visual inspection, the Kaihua Temple mural includes five horizontal bracings directly connected to the borders of the two sides, such as small five woods and large five woods, which are completely consistent with the position and number of "Standing Machines" of the "Zi Ren Relic System".

2. Song and Yuan "vertical machine" pedal transmission differences

In the pedal structure, the double pedal of the "Zi Ren Relic" is one long and one short, and the connection is formed at an angle of nearly 90 degrees, kaihua Temple adopts a long pedal, the tail end of the pedal in the picture has been under the bench and lined with bricks (Figure 7), and the front end and the connecting rod connection form a 120-degree angle, in order to be able to obtain greater potential energy, the rear end of the pedal is lined with bricks to reduce the angle, which also means that the "Zi Ren Relic" "Stand Machine" pedal is improved, and the design of the "hinge" is added to make the pedal shorter. However, another function of the Kaihua Temple Long Pedal is to move the transmission force backwards, which can well balance the gravity of the front reed and ensure the stability of the fuselage. This is also the use of rear support in the mural and the use of low-footed triangular braces in the "Zi Ren Relic System". Comparing the structure of the rear support with Zhao Feng's restored loom, the rigid connection of the double wooden pole is obviously a reference to the kaihua temple image, which clearly shows the structure of the connecting rod and the two ends (Figure 8). Since the Ziren Relic Does not have a narrative and pictorial depiction of this part, and there is no relevant research image data of the Kaihua Temple murals in the Kuhn research period to learn from, it can only use Western chain traction. Zhao Feng also confirmed through the actual restoration that only the rigid structure can ensure the effect of this pedal transmission on the guide. ([1], p. 149) It can be seen that the connecting rod structure of Kaihua Temple is of great significance for the restoration of physical objects. In addition, this part also includes rabbit ears, hinges, foot pedals, lower foot bolts, and rear feet in the "Ziren Legacy", which are mainly structures that use mortise and tenon threading to ensure foot pedal installation and shaft levers.

3. Structural differences in the warp distribution device

This part is the most complex mechanical structure of the loom and the key to the opening of the warp thread. Including the five parts of Tengzi, Xiao Wumu, Large Wumu, Horse Head, and Arm Knee, each of which is an independent work unit, interlocking and involving each other. Tengzi is not depicted in the illustrations of the Ziren Relic, and therefore is not reflected in Kuhn's restoration. This structure is reflected in the mural, so there is a similar reference in Zhao Feng's restoration machine (Figure 9), the "Zi Ren Relic System" said that its shape is "or round eight, make Teng's ear diameter", the mural is the use of cross-crossing, Tengzi is the mechanism of fixing the warp, it and the scroll installed in the knee constitutes the end-to-end structure, before the cloth, the top must be fixed, the warp is straightened and then directly reversed so that it is rolled into the Tengzi, and the tail end is controlled by grouping and binding tightly to the scroll, and with the weft weaving, the "upper loose and tight" is achieved. The beginning and end echo the relationship, which is also the basic link of weaving work.

In this link, the small five woods and the big five woods are very critical core sub-meridian devices, and the "Zi Ren Relic System" Li Ji Zi Gong Limit article quantifies the efficacy of each part, ([2], p.83) Although it is only an estimate, its role size is indeed as described in the text. The role of the small five wood is only to fix the movement of the tengzi, and the big five wood is actually the central axis, which belongs to the core device of "pulling a hair and moving the whole body", the rear pedal, which is carried by the guide hand, and the front has the design of the forefoot hand and the drooping hand. （[1]，p.148）

The horse head part is a warp surface separation area, composed of sorghum wood, open silk wood and crow wood and curved elbows and other structures, the "Zi Ren Relic" vertical warp surface in this part bypasses the sorghum wood and the crow wood to form two turns and divide the meridian. In the murals of Kaihua Temple, only sorghum wood can be seen passing through the horse's head. The curved elbow connected to the horse head machine is not marked in the "Ziren Relic System", Zhao Feng set it in a wooden stick connected by small five woods, and realized the first division of the scriptures, but in the murals it can be clearly seen that this device appears independently, and the division also begins here, its position is connected to Tengzi, the lower is limited to the horse's head, and the middle is penetrated into the palm hand, which is quite different from Zhao Feng's restoration. Chen Weiji discussed that from the big five wood to the horse's head, the warp yarn realizes the role of the split twist opening and press the warp. ([3], p. 226) However, the key to Zhao Feng's division occurred from the silk wood, which is quite different from the mural structure. Kuhn also refers to the "Ziren Relic System" in the restoration of the horse's head, ([2], p.80) The difference is that the two ends of the sorghum wood have extension devices and use hinges to fix the "hanging fish" and eventually link with the foot pedal, which is suspected of being "patched" according to xue's legend, while there is obviously no such structural expression in the murals of Kaihua Temple. （[9]，p.87）

4. Auxiliary components of the wefting device

Including three parts: brown frame, basket frame (筘) and shuttle, the brown frame is the main device to maintain the transverse traction of the warp opening, which is bound by silk thread and single-sided warp, and the rectangular frame structure can be seen in the mural. The weaver woman in the mural holds a shuttle in her left hand and a flute in her right hand. In the structure, the length of the reed is comparable to the width of the fabric, Xue's statement that "the flute is two feet and four inches long, one inch and five minutes wide, and six points thick", which was used in ancient times as a bamboo raft, and its functions are three: 1. determine the width; 2. Distribute the warp wire evenly; 3. Punch the weft line into the warp wire shuttle. ([6], p.39) There are also two key structures, the plug eye and the grasshopper eye, ([2], pp.80-83) in the control of warp density and width, as well as in the layout of the pattern, by penetrating the weft thread into it to achieve variation. Kaihua Temple and the "Palace Silkworm Diagram" have fixed herringbone rope lines on the reed, Zhao Fengwen mentioned that this kind of suspension may use elastic bamboo poles, but from the analysis of the two pictures should be a herringbone-shaped suspension structure such as a rope, this device can ensure that the reed always stays on the working surface, and returns to the high point to stay parallel after wefting. The shuttle is a general weft guide, and the fresco bench also has a spare shuttle. The "single-round double-wrenched" loom is relatively simple in structure, and its working principle is to step, open and weft, but this design is still used today.

3. Details of the pictorial studies of the "Standing Machine" of Kaihua Temple

1. The pictorial authenticity of the Kaihua Temple image "Li Jizi"

Whether the image of the kaihua temple mural loom has absolute authenticity, the gap between the source of the image and the actual sketch cannot be verified at all. However, through the research and restoration of Zhao Feng and Kuhn, a more objective judgment can be made, and this "vertical machine" diagram is an important reference for restoring the "China Silk Museum" and "vertical machine", with the following three points of evidence. First, the "Tengzi" mentioned above, as the top scrolling device, was obviously assembled through the image reference of Kaihua Temple. Second, the connecting rod structure has absolute significance in the clear representation of the image (Kuhn uses a chain soft connection). Third, the position of the hanging fish, Kuhn used the hanging fish as a turning device to link the sorghum wood and the foot pedal, which is obviously wrong. Zhao Feng in the process of restoration because the image reference to ensure the real structural direction, these are the Kaihua Temple murals fine depiction for the restoration to provide a chain of pictorial evidence.

In addition, in the restoration of the China Silk Museum, there is also a structure that is not very clear, due to the legitimacy of the text of the "Zi Ren Relic System", all the research is overly dependent, its expression is sometimes not comprehensive enough and the catalogue does not specify, which is a problem faced by the restoration. Among them, the sub-comprehensive structure of the horse head part is the key focus as the core. Zhao Feng used warp yarn to bypass sorghum wood to divide the warp between the open wire and the pressed warp wood, and the long and short foot pedals controlled the movement of the healds back and forth. The murals of Kaihua Temple obviously have a big difference from this, first of all, there is only one sorghum wood in the horse head part, and no silk wood and crow wood are found. The opening of the loom weft yarn in the fresco is fully open from the horse's head part, the sorghum wood is responsible for lifting the front warp, and the silk wood is responsible for the back warp, and there are no more turns.

Compared with Zhao Feng's restored standing machine, the horse head of the Kaihua Temple mural is wider. From the analysis of the image, the heald frame actually bypasses the inside of the horse's head and has a shaft-like flexible connection, tracing back to the source, because the assembly of the large five wood and the palm ten wood in the mural is completely different. (Fig. 10) The palm tenmu is depicted in great detail as the vertical support of the tengzi and passes through the upper palm hand in the small five wood parts, and in order to show the structure, the structure related to the palm tenmu is depicted in a downward perspective. The shape of the palm tengmu is also similar to the upper width and lower narrowness recorded by Xue, with the upper end and the groove supporting the teng shaft. The large gomu in the "Zi Ren Relic" is pinned to the frame like the small gomu, while the big gomu in the mural is obviously not so deviced, but is inside the open warp after being pinned with the palm of the wood, and its two ends are respectively mounted in the semicircular device groove, and this device is similar in appearance to the "hanging fish". The "hanging fish" in the "Ziren Legacy" is to connect the sagging hand, and this "hanging fish" with a shaft assembly has completely changed in function, and the absence of the sagging hand means that the position of the "curved elbow" naturally changes, and its linkage method is completely different. This assembly method is entirely due to the structure formed by the different positions of the warp openings. Due to the open structure of the large gomu position, the left and right rear guides in the image (Figure 11) are still connected to this, but the hanging hands are not visible.

Summarizing the above, in order to show the objective truth of the details of the image, there are the following details. First, the position structure of the large five wood and the palm ten wood; second, the detailed depiction of the frame support; third, the rear lead linkage structure is a suit, not a mortise and tenon structure, which is convenient for adjusting its angle; fourth, the flexible shaft connection between the horse head part and the brown frame; fifth, different shuttles are placed on the bench to prove that it replaces different silk threads; sixth, the herringbone reed rope is bending through the heald frame. These details are difficult to express if they are not sketched in the field and repeatedly examined.

Kuhn's research has been published as early as 1977, the image of Kaihua Temple was only published in the 1980s, from the time due to the lack of reference to the murals of Kaihua Temple, Kuhn can only make simple speculations, and combined with the sleeping machine for restoration, therefore, the error of its installation is closely related to the insufficient image data. It is precisely because Zhao Feng is exposed to this image that he will "see the clouds and see the sun" in many ways, but the loom that relies too much on the "Zi Ren Relic" to restore it integrates many characteristics of the Song and Yuan "standing machines". The mural shows the high coincidence of the frame with the style of "Zi Ren Relic" and the high waist back support and side fixation are obviously the picture details that the painter can get after detailed sketching in the field, and the so-called "meticulousness" just achieves the "meticulousness" of this image.

2. The working principle of the "standing loom" of Kaihua Temple

Studying the occurrence and disappearance of the "vertical loom" is the most direct example of the evolution of ancient Chinese fabrics in the process of social form, as can be seen from the foregoing, this loom is a single fabric machine, which is particularly simple compared to the complex "jacquard machine". From many studies, it has been found that because ancient China was not keen on technical bibliography, the "Ziren Relic System" became the most important reference for the restoration of this loom. From the working principle, the oblique loom of the Han Dynasty and the vertical loom painted by the Kaihua Temple are both mechanical extensions of the waist machine, which also means that this loom with a pedal pulling the opening belongs to the most direct evolution of the original loom. Although it is recorded in detail in the "Ziren Relic System", it is not difficult to find that its diagrams still have unclear expressions, especially in institutions such as crow wood and curved elbows. Zhao Feng restored two vertical machine sub-assembly drawings, the back of the main drive, the long and short pedals and the rear guide as the main drive. The two states A and B in the figure represent the up and down movement of the left and right guides to promote the work of the central axis. In the assembly mechanism, the two warp lines go from the "parting ways" of the horse's head part to the "special way and the same destination" of the scroll. Its sub-warp occurs by the sorghum wood after the solid line Y bypasses the c-point open silk wood, the dotted line (the separated warp surface is represented by the solid line and the dotted line respectively) X bypasses the d-point pressure warp wood, the heald is connected by the X-side warp line, controlled by the hanging fish traction, when the long foot pedal works, the hanging fish is lifted by the hanging hand driving the curved elbow in, and the warp opening of the A figure is obtained by mechanical tension compensation. ([1], pp.152-153) (Fig. 12) and Kuhn's assembly work diagram is similar to this at the junction of the foot pedal and the rear lead, due to the wrong understanding of the parts, resulting in the assembly of the front mechanism being overly complex, the foot pedal controls the rear lead and the hanging fish at the same time, because there is no setting of tengzi, the warp yarn is separated by the small five wooden palm hand H, a section of warp yarn is wrapped around the inner axis J and then wrapped around the open silk wood K, after the external force wood O ends and the knee out of the warp shaft P. The other part of the warp is wrapped around the sorghum wood L on the outside and the silk wood M on the inside is returned to one place by O. ([2], pp.104-105) (Figure 13) Discarding the difference in assembly, Kuhn leaned closer to the opening setting.

Regarding the restoration of the standing loom of the China Silk Museum, the author of this article went to the China Silk Museum to conduct field research, and clarified its working principle and assembly structure through the demonstration of the engineer Luo Qun in the museum combined with the description of the article, (Figure 14) This also provides specific practical experience for the further demonstration of the "standing machine" of the Kaihua Temple. From the mural image analysis, its working principle is as follows, the opening of the warp line is basically the same as the position of the small five wood, because the connection between the big five wood, the palm tree and the hanging fish structure is different from the above two restoration diagrams, so the control of the heald piece should be the suspension of the fish in the big five wood under the action of the rear guide to pull the horse head part of the winding flexible belt to do shaft transmission to promote the brown frame forward and backward movement, belongs to the typical wheel axle type lever structure, this kind of lever that can be continuously rotated belongs to the typical labor-saving lever. Its friction is relatively small, and it can achieve the swing of the hanging fish through the push of the left and right guides, so as to drive the axle, the left step is the top of the palm tengmu to promote the hanging fish to pull backwards, forming the first movement, and the brown frame is pulled backwards, which is the first opening, the right palm tengmu is downward, the hanging fish is pendulum, and the belt is relaxed to form a second opening. After the shuttle is beaten, it is reciprocating in turn to form a weaving surface. This structure is not similar to the front and rear openings of the tension compensation obtained by Zhao Feng li machine in the mechanism linkage, but the two energy efficiency conversions carried out by the pedal drive and then pulling the big five wood and the palm teng wood, this lever structure is very clever, if a certain speed can be formed during the rotation process, the operation will be more efficient. This bold idea can be seen in Kuhn's hanging fish assembly, so he has a certain similarity with the Kaihua Temple loom by assembling the curved elbow and the hanging fish for half-wheel axis movement.

At the same time, this assembly structure makes use of the vertical working surface characteristics of the "vertical machine" warp, and the warp is pushed by the brown frame under the horse's head to cross the opening, which seems to be a simpler structure. The design of the axle obviously takes the design of the curved elbow and the hanging fish to the extreme. Although the structure of the horse's head is not visible in the frescoes, bold inferences can be made from the reconstruction of the horse's head.

The vertical machine of the "Ziren Relic System" belongs to the improved model of the Jinnan region of Shanxi in the early Yuan Dynasty, especially the central axis and the curved elbow structure were reset, so the hanging fish is not the final pulling structure, and although the structure inside the horse's head cannot be fully displayed, if the curved arm shaft still exists, whether it is connected with the invisible drooping hand cannot be understood in the mural.

epilogue

The Northern Song Dynasty vertical machine of Kaihua Temple emphasizes the combination of soft and hard traction in the energy efficiency conversion, and the mechanism seems to be more ingenious than that of Xue's vertical machine, but due to the great changes in the central axis structure, the relationship between the part of the meridian and the warp surface is also quite different. Compared with the vertical machine in the five generations of Dunhuang, a very advanced linkage technology has been developed. Although the standing machine in the 6th library of the Five Generations of Mogao Grottoes also has long pedals and rough frame depictions, ([4], p.101) but it is difficult to distinguish its transmission mode and specific structure from the picture, it can not be used as an assembly or restoration reference, which is also the advantages and disadvantages of the realism of the ancient mural images and the degree of reference, after the Yuan Dynasty, the advocating freehand style is popularized in the painting world, the neat and rigorous image is despised, although some painters still like this, but in the end to avoid painting techniques are degraded "vulgar", still based on yiqi drawings. After the Ming and Qing dynasties, folk craftsmen did not have the technical guidance of upper-class painters, and their work gradually lost their "authenticity", coupled with the loss of powder books, the degree of stylization of images and the meticulous sketching of life were far behind that of the Song and Yuan Dynasties, and Chinese painting at this time was getting farther and farther away from graphics. The ultimate depiction of Kaihua Temple even goes beyond the legend of the "Ziren Legacy", and each link in it is fully displayed in this angle, which shows that this kind of "genre painting" in the Northern Song Dynasty has a high pictorial value.

In terms of the main assembly structure, there is a certain difference between the Kaihua Temple standing machine and the "Ziren Relic System" standing machine, and Zhao's current restoration draws on many images, not the Standing Machine of the Song Dynasty. The spindle displacement of this figure is the most critical place, and the most important structural linkage also occurs here. The length of the rear guide of the spindle in the image allows for the front and rear adjustment of the connecting rod and pedal, which does not match the dimensions contained in the Ziren Relic. But this seemingly lacking "rigorous" design is precisely the flexibility required by the manual mechanical work process. For the position of the hanging fish, the Xue drawings are also depicted in the horse's head part, installed in the opposite direction. And there is a magnified image, which is also different from the structure of Kaihua Temple. Although the relationship between the hanging fish and the curved elbow cannot be seen, the connection with the central axis also shows that the structure of the Song Dynasty vertical machine is different. These structures prove that the Kaihua Temple Standing Machine is a very important branch of the pedal single comprehensive loom, and it is also a kind of loom common in the Shangdang silkworm flourishing areas in the Song Dynasty. (Figure 15)