In order to cast gold using the lost wax method a wax model must first be prepared. The model (foa) is formed by rolling and shaping softened wax on a wooden block known as adwini pono (the craftsman’s table) using a wooden spatula (adwini nua). The wax model is built up by combining prepared wax pieces and strips which are attached to the main body of the model by touching the point of contact with a hot metal blade or rod. Once the model has been shaped the details and decoration are added by cutting, incising and carving into it using heated blades (sekan), a wood or bone spatula (tabono, adwini ba), a pointed bamboo stick (adwini dua) and an iron needle (hyehyeye). When the model is completed the smith attaches one or more thin hollow wax rods in places which will be unobtrusive in the final casting. These rods will eventually protrude through the clay mould and melt away during the casting process leaving channels through which the molten gold can flow into the mould.
Once the wax model has hardened off completely the smith either dips or paints a layer of very fine clay slip, which has been mixed with finely ground charcoal, over the model taking care to ensure that all parts are covered. After the first layer of slip has dried further layers are added until the clay casing measures around half a centimetre in depth. A thick outer casing is formed by carefully pressing wet clay around the inner clay slip casing. The completed mould is then allowed to dry for several days. Before the casting takes place, the mould is heated in the furnace (ebura) until it is very hot and then inverted. This allows any molten wax which has not soaked into the mould walls to be tipped out. After the mould has cooled down a small clay cup (semoa) containing small pieces of gold is grafted over the holes left by the wax rods. Clay is then plastered heavily around the joins and the mould is allowed to thoroughly dry.
On the day of the casting, the mould and cup are placed in the furnace, the cup downwards, until the gold is judged to have become completely molten. This process requires that the charcoal fire is kept at a constant high temperature by having air pumped into it by bellows. At the right moment the mould and cup are seized with a pair of tongs (da) and swiftly inverted, which causes the molten gold to rush down the channels and into the cavity. The mould is held in this position, or placed on the ground, while the molten gold cools and hardens within the cast. The mould is then smashed open and the casting is picked out. When it has completely cooled the casting is cleaned by picking off the blackened mould material which has baked on in the heat. It is then scrubbed in water mixed with the juice of limes and is trimmed and finally polished with a paste of very fine clay and a soft cloth.
Several items of regalia in the British Museum’s collection that date to 1818, 1874 and 1900 show evidence of having been made by either the same goldsmith or in the same workshop. This identification was aided by the fact that a relatively small number of goldsmiths worked under the direction of the Asantehene at any one time (McLeod 1981, 79–80). These men were assisted by apprentices who were taught by their masters, hence pieces of gold-work collected at specific moments in time exhibit similarities in size, decoration, style and manufacturing techniques. Bowdich mentions in his account that one goldsmith was responsible for casting the ornaments that he later donated to the British Museum (see nos 2.1, 2.2, 3.42, 3.43 and 3.52). This individual, whose name was not recorded by Bowdich, was prevented from putting the finishing touches to his work, however, as he was suddenly sent to prison for an undisclosed offence (Bowdich 1819, 311).
The hand of another anonymous goldsmith and/or individual workshop can be detected in the treatment of a series of disc pendants that were acquired in 1874 (see 2.15, 2.17 and 2.18). The same maker also appears to have been responsible for casting two disc beads from the same assemblage (4.1 and 4.2). Another group of disc pendants that date from the Anglo/Asante war of 1900 also share common features that indicate that the same goldsmith was responsible for creating them (see 2.10, 2.11, 2.12, 2.13 and 2.14). Other artefact types such as the numerous small orb-shaped crotal bells, which in Europe were associated with horse harnesses (see 3.47, 3.48, 3.49, 3.50 and 3.51) and the two identical bracelets (6.2) that share similar dimensions and have a uniform look may also have been made by the same goldsmith or, at the very least, in the same workshop.
A few pieces of gold regalia in the British Museum’s collection also retain evidence of the lost wax casting process. The most common traces take the form of burned-on mould material which adheres to interior spaces or recessed areas that are hard to access. Another residual feature takes the form of sprues, little raised pieces of cast metal that indicate where the wax rods were originally attached to the wax model. These are normally filed or smoothed off during the finishing stage but some have been missed (see 1.7). Other items also reveal something of their method of construction. One of the disc pendants (no. 2.3) for example, was modelled using a very thin sheet of wax onto which tiny flat coiled spirals were pressed in a pattern of five concentric circles; the imprint of some of these can be seen on the reverse, as can the negative shapes of the central boss and the encircling petal ring at its base.