Introduction
[FIGURE 2 OMITTED]Two other key objects take the form of hollow, bronze cones of 100mm and 180mm in length, each with a tine hole in the end (Figure 5). These have been identified as drawing plates for the manufacture of threads (Uroz Rodriguez 2006: 43-44, fig. 16). Computed Tomography images generated as part of our study have revealed that the original section drawings of these tools are incorrect (Figure 6). The walls of the cones are thinner than shown in the original diagrams, and the small hole at the end was approached via an interior step. This complex internal design, along with the shape and material of these two objects (drawing plates are usually flat, iron objects) does not correspond to the production of threads. Rather, these cones would have been used to produce a high pressure stream of air. Air would have been introduced at the wider end and have escaped at a greater pressure through the tine hole. Similar blowpipes are still used by some jewellers today. Modern blowpipes have the same configuration as those found in Tomb 100, the only difference being that the end of modern brass cones are bent at 90[degrees] to provide the jeweller a better view of the work area (Untracht 1987:410-11). It seems highly likely that these two objects are blowpipes for brazing gold.Shaping. once weighed and cut, the raw material was melted in a crucible. The ingot obtained was then beaten with a hammer until a sheet of the desired thickness was obtained. This stage is represented by the larger tools found, including iron tongs for the handling of crucibles, and two anvils. One of the latter, made of iron, is poorly preserved; the other, in bronze, has a circular work surface 47mm in diameter that shows signs of deformation owing to prolonged use (Figure 2b). This group of tools also includes a bronze socketed hammer (Figure 2c), the head of which measures 104 x 128mm. It is poorly preserved having been found within an encrusted mass of highly oxidised iron objects. Finally, there is a small saw that may have been used in some way for the transformation of the raw material.The goldwork of Iberia in the first millennium BC is justly famous (Figure 1). It is characterised by brazing, filigree and granulation--the 'Mediterranean trio.' These techniques can be traced back to 2500 BC in the Middle East (Wolters 1983), but reached technical and iconographic excellence during the Iron Age of Mediterranean Europe. Brazing is the permanent metallurgical joining of metals to form a single more complex, more voluminous or hollow object, using high temperatures and a filler alloy (solder). This method lies at the heart of filigree and granulation, two of the oldest jewellery-making techniques, which involve the use of tine threads and tiny gold drops respectively, brazed to a laminar base to form ornamental patterns. The grave goods from Tomb 100 at the Iberian necropolis of Cabezo Lucero throw new light on goldworking processes in the mid fourth century BC.The materials found in Tomb 100 reflect ali of the stages of jewellery production, from procuring the raw material, to its shaping, ornamentation, and finally joining.[FIGURE 4 OMITTED]A goldsmith's toolkitThe necropolis of Cabezo Lucero (Guardamar de Segura, Alicante), lies in the lower valley of the River Segura, 6km from its current mouth. The corresponding fortified settlement is approximately 200m to the north and, so far, has not yet been fully excavated. The necropolis covers an area of approximately 4200[m.sup.2] and dates from the early fifth century to the early fourth century BC. Tomb 100 contained the remains of an adult warrior. In addition to his standard military equipment the tomb contained a complete goldsmith's toolkit including some 50 specialised instruments. This exceptional find was recovered during excavation in 1986 but has remained unstudied until the present. Some of the instruments went on public display in 1992 as part of a small exhibition at the Museo Arqueologico de Alicante (Llobregat 1992), and at an exhibition (The Iberians) held at the Grand Palais de Paris (Aranegui-Gasco et al. 1997: nos. 69-78). Recently, 31 bronze dies--part of the set of tools discovered--were the subject of a monograph focusing on their iconography (Uroz Rodriguez 2006) and an article reflecting on the status of artisans in Iberian society (Graells 2007). Some of the grave goods found in Tomb 100 are currently on display at the new Museo Arqueologico de Alicante.A mouth blowpipe has a double purpose: first, to raise the temperature of a heat source; and second, to direct that heat towards a desired point. The heat source could be a simple oil or animal fat lamp, the flames of which can reach around 1000[degrees]C. Blowing air across the flame allows even higher temperatures to be reached while channelling that heat in a specific direction. Depending on the intensity of the airflow and the combustion zone, either an oxidising or a reducing flame can be directed at the desired point--the latter is required for brazing in jewellery-making. The heated metal changes in colour depending on the temperature reached, from dark red to orange to white, facilitating the visual calculation of the temperature attained. In this way the melting point of part of a small metallic mass can be reached without affecting the surrounding area, allowing a filling gold alloy to melt in between the two pieces effectively fusing them together. The phase diagrams of the AuAg-Cu system (Prince 1988), which show the melting points of the different combinations possible (ranging from 800[degrees]C for alloys with the lowest melting points to 1064[degrees]C for pure gold), indicate there to be ample margin for the efficient use of mouth blowpipes in jewellery manufacture. In addition, the control gained over the metal's temperature obtained by observing the change in colour is better than that possible when placing the entire object in a furnace.Procurement: two balance plates have been identified; both are now highly deteriorated and fragmented (Figure 2a). One, about 40mm in diameter, is not perforated; the other, 72mm in diameter, has a central perforation. This weighing system also includes a disc-shaped weight with an unusual perforation and four incised points (Figure 2a). Its current weight is 9.36g.The joins made by brazing performed with a mouth blowpipe cannot be distinguished from those involving brazing performed in a furnace and, until now, mouth blowpipes have never been identified as such in the archaeological record. Apart from the shape of the objects themselves, is there any evidence that could support the proposed interpretation of the two bronze cones from Tomb 100 as mouth blowpipes?Our purpose here is to describe this remarkable assemblage and demonstrate its contribution towards understanding the techniques and context of goldworking in the Mediterranean Iron Age.[FIGURE 1 OMITTED][FIGURE 3 OMITTED]Use of the brazing blowpipesJoining: complex jewellery was made by putting together independently manufactured pieces, or decorating them by affixing filigree (tine wire) or granules (gold droplets). Brazing was required to fix the different elements together. Tools connected with these operations are rare but can be identified within the assemblage. One of the grave goods was a pair of bronze tweezers originally classified as belonging to the warrior's personal effects (Uroz Rodriguez 2006: 41) (Figure 4c). However, Iberian men's tweezers had straight ends, appropriate for looking after the beard, but the tweezers of Tomb 100 have pointed ends. It is therefore proposed that rather than being a masculine status symbol, these tweezers are a tool for holding and arranging threads of filigree and granulation spheres on the surface of a worked sheet.
A mouth blowpipe has a double purpose: first, to raise the temperature of a heat source; and second, to direct that heat towards a desired point. The heat source could be a simple oil or animal fat lamp, the flames of which can reach around 1000[degrees]C. Blowing air across the flame allows even higher temperatures to be reached while channelling that heat in a specific direction. Depending on the intensity of the airflow and the combustion zone, either an oxidising or a reducing flame can be directed at the desired point--the latter is required for brazing in jewellery-making. The heated metal changes in colour depending on the temperature reached, from dark red to orange to white, facilitating the visual calculation of the temperature attained. In this way the melting point of part of a small metallic mass can be reached without affecting the surrounding area, allowing a filling gold alloy to melt in between the two pieces effectively fusing them together. The phase diagrams of the AuAg-Cu system (Prince 1988), which show the melting points of the different combinations possible (ranging from 800[degrees]C for alloys with the lowest melting points to 1064[degrees]C for pure gold), indicate there to be ample margin for the efficient use of mouth blowpipes in jewellery manufacture. In addition, the control gained over the metal's temperature obtained by observing the change in colour is better than that possible when placing the entire object in a furnace.
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