Chinese bronze

Angus, T. (1976), Cast Iron Physical and Engineering Properties, Butterworth, London. Anheuser K. (2000), Amalgam tinning of Chinese bronze antiquities, Archaeometry 42,... 

AAS has been widely used in Europe to study archaeological ceramics and metals, ranging from Chinese celadons (Pollard and Hatcher 1986) to Roman terra sigillata (Mirti et al. 1990), and from Renin bronzes (Willett and Sayre 2000) and Islamic brasses (Al-Saad 2000) to Chalcolithic and Early Bronze Age copper alloys from ancient Israel (Shalev 1995). ICP-AES, using solution sampling, can potentially provide data on a wider range of elements... 

In about 3600 bce, ores containing both arsenic and copper were known and mined by the early Greeks and Romans, as well as by Chinese alchemists. This is about the time when copper was smelted and alloyed to make bronze. Some ores of copper produced harder metals than others because of impurities. One of these impurities was arsenic. Because the workers were becoming ill when smelting these types of ore, the process was abandoned, and tin was added to copper to form bronze. Bronze may have been the Persian (Iranian) word for copper. ... 

Last, but not least, there is the intentional coloring or patination of metals, of prime importance in sculpture and decorative arts, as this is (in many cases) the key factor in the visual coherence and significance of objects. There is some evidence of their early use in Chinese bronze mirrors, in Japanese sword guards made with alloys especially developed for patination, in the classical Greek and Roman bronzes, in Islamic metalwork, and in cast bronze sculptures from the Renaissance to the present day [280]. 

Figure 1. Top Shang Dynasty Chinese bronze ku (wine beaker) in fragmentary condition. Freer Gallery Study Collection No. SC528 or SC-B-I, 13 cm highy before sectioning and comminution. Bottom after sectioning.

Gettens, R. J., The Freer Chinese Bronzes, Volume II, Technical Studies, ... 

The first seismograph is recorded to have been an inverted bronze urn with a pendulum inside and used by the Chinese in about 160 A.D. to announce earthquakes. Seismographs were reinverted, so to speak, during World War T to locate heavy German artillery. In 1920, scismography for use in petroleum exploration was first demonstrated. 

Two hundred twenty four Chinese coins (Song Dynasty, ca. 990-1080 A.D.) were analyzed via energy dispersive X-ray fluorescence spectrometiy for the following elements copper (Cu), zinc (Zn), tin (Sn), lead (Pb), iron (Fe), nickel (NO. manganese (Mn), antimony (Sb), gold (Au), platinum (Pt), palladium (Pd), and silver (Ag). The coins routinely appear to be leaded bronze. However, the amount of lead present in these coins was in many cases significantly higher than expected. 

Ferrocyanide blue occurs in various shades known as Prussian blue, Chinese blue, muon blue, bronze blue, Antwerp blue, and Turnbull s blue. These names have lost much of their original differentiation the more general term iron blues is preferred. 

Zinc oxide is a very old technological material. Already in the Bronze Age it was produced as a byproduct of copper ore smelting and used for healing of wounds. Early in history it was also used for the production of brass (Cu-Zn alloy). This was the major application of ZnO for many centuries before metallic zinc replaced the oxide [149]. With the start of the industrial age in the middle of the nineteenth century, ZnO was used in white paints (chinese white), in rubber for the activation of the vulcanization process and in porcelain enamels. In the following a number of existing and emerging electronic applications of ZnO are briefly described. 

Chinese and Japanese bronze mirrors dating from the first, fifth, seventh, eleventh, and twelfth centuries have been found to contain between 62 and 74 per cent, of copper associated with other metals. A Corean mirror of the tenth century contains 73 per cent, of copper, and considerable proportions have been found in ancient coins, arrow-heads, and water-pots from these lands.5... 

The first archaeoli cal record of bronze production in China comes from an Eifitou Culture (1700 B.C.) site in Henan, Shanxi, China [6]. Bronze is an alloy of copper and tin (althou in ancient China, lead was also fi equently used). The eailiest known Chinese bronze object is shown in Figure 1.4, uiiich has 92% copper and 7% tin. This wine cup displays the basic metalworking features of the Chinese Bronze Age, which are sharply different from Near Eastern and Western traditions. This alloy is not an accident but a deliberate choice and indicates that a complex metalluigical infiastructure was in place to mine the ores of both metals and then smelt each ore to its respective metals. 

Most important, this bronze vessel has seams which show it to have been cast from a mold made in four separated sections. This wine cup required a complex ceramic mold, which sets the early Chinese bronze technology apart from the lost-wax process used in the West. 

FIGURE i.5 (a) Diagram showing how early Chinese bronzes were formed (1) the model, (2) the sections of the mold, and (3) schematic of completed vessel. 

Hopes and Limitations, in The Procedings of a Symposium on Scientific Methods of Research in the Study of Ancient Chinese Bronzes and Southeast Asian Metal and Other Archaeological Artifacts, pp. 255-298, National Gallery of Victoria, Melbourne, 1975. 

B.C. and the famous Bronze Horse was cast by the lost wax process and not, as had been suggested, by a modern piece-mold sand casting process. In addition. X-ray radiography helped to provide details on the methods of manu-factuer of Sasanian silver and a Chinese bronze vessel. 

Among the objects most susceptible to successful radiographic study are those with well-defined internal structures such as cast bronzes, jewelry, furniture, musical instruments, and ceramics. The variety of materials that have been studied is described in the literature. For example Bridgman reported on the radiography of museum objects (9), Gettens examined Chinese bronzes (iO), Gorelick studied cylinder seals... 

CraNESE Bronze Vessel. Scholars had never fully understood how the copper figures that decorate the surface of a Chinese vessel of the late Chou dynasty (Figure 11) were applied inlaid hardly appeared to be a satisfactory description. (The questions regarding the method of manufacture of this object were brought to the attention of the Metropolitan Museum of Art Research Laboratory by W. T. Chase.)... 

Figure 11. Chinese Hu (ritual vessel), late Chou Dynasty, bronze with copper decoration. The Metropolitan Museum of Art, Acc. 29.100.545.

Ternary Representations of Ancient Chinese Bronze Compositions... 

Ti etal compositions of Chinese bronze ceremonial vessels and other bronze objects have fascinated scholars for some time. It seems that Chinese bronze founders must have had good intuitive control of composition. They must have considered the final uses of these objects and must have adjusted the compositions accordingly. Economics, availability of ore sources, trade routes, and many other factors influenced the metals placed in the crucible. One has long thought that the compositions of ancient Chinese bronze objects should vary in a regular manner with the time and place of manufacture and with the object type. 

Before examining what other scholars have found concerning ancient Chinese bronze compositions, let us first look briefly at the population of bronzes with which we are dealing. With a few exceptions, the chronology of Chinese history is clear. Table I is a chronological table of Chinese history adapted from a recent publication of the People s Republic of China (I). The information in this table is firmly based on Chinese historical records (2,3),... 

Bronze production began in China possibly in Kansu province in the early Shang dynasty or possibly in the late Neolithic period. These few isolated finds do not seem to have any relevance to later Chinese bronze production, and we have not included analyses of any of them in our tables. The mainstream of bronze production begins in the Homan area, probably about 1400 B.C. with workshops near Cheng-chou, which at that time probably was the capital of the Shang state. These early (pre-An-yang) bronzes have characteristic decoration, shapes, and thinness. 

At the end of the T ang Dynasty and in the Sung Dynasty, interest in Chinese archaeology began in China (5). Great numbers of vessels were made as reproductions or archaistic imitations of early bronzes some of them were actually fakes or forgeries (6, 7). Even today reproductions of ancient vessels are being cast in the People s Republic of China and on Taiwan (8). 

The bronze production in China was both long-lasting and extensive. A lot of bronzes were produced in these 3000 years As an example, over 1295 mirrors have been excavated and listed in publications during 1923-1966 when Barnard compiled his tables (4). When we add the pieces in Western collections which have come out of China without provenance data and the numbers of objects lost, still undiscovered, or melted down as scrap, the totals are staggering. The story of Chinese bronze alloy compositions is a complex one. 

Earlier studies of Chinese bronze alloys have been compiled by Barnard and others (4,9). Needham s book (10) contains a fine bibliography. Most of the authors come to the same conclusion as Gettens (7) ... 

Barnard looks closely at the lead compositions of bronzes and concludes that Shang bronze is for the most part a binary alloy (4). In Western Chou bronze was a ternary alloy with 2-7% lead, and in Eastern Chou the Chinese bronzes have higher lead. This, indeed, seems to go along with what we found. Barnard stresses, correctly, the problem of working with unprovenanced material—objects which have not come from archaeological excavations and which have no reliable data about their sources. In any case, the picture of ancient Chinese bronze alloying seems to be complicated and confused. No clear conclusions have been drawn, and no firm picture emerges. 

CHASE AND ziEBOLD Ancient Chinese Bronze Compositions 297... 

Figure 1, Chemical composition of objects Z71.16 and Z76J7 compared with that of 92 Chinese bronze vessels in the Freer Gallery of Art (7). (left) Shang and Early Chou vessels (right) Late Chou objects. Comparison of objects Z76.16 and Z76.17 with 92 Freer ceremonial vessels. The numbers in boxes show the number of vessels having the composition range enclosed. ( ), center of gravity of each distribution. The reported compositions of objects Z76.16 and Z76.17 are shown as Z76.1S—O body ) handle cover. Z76.17— body ...

Figure 2, A ternary plot of Chinese bronzes analyzed at the Freer Gallery of Art, The mirrors ( ) form a distinct, high-tin group. (O), Shang ceremonial vessels (34 points) (+), Early Chou ceremonial vessels (31 points) (A), Middle and Late Chou ceremonial vessels (31 points) ( ), Chin and Han ceremonial vessels (5 points) ( ), Later ceremonial vessels (19 points) ( ), mirrors (27 points) (<), Ming Knife Coins (8 points) (>), belt hooks up to Han (147 points) ( ), later belt hooks (6 points).

When this diagram is superimposed on the diagram of ancient Chinese bronzes, one sees the tendency of the compositions to come down from the high-tin area and cluster along the limit of miscibility. The... 

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