X-ray Tomography Unveils the Construction Technique of Un-Montu's Egyptian Coffin (Early 26th Dynasty)

Abstract

The Bologna Archaeological Museum, in cooperation with prestigious Italian universities, institutions, and independent scholars, recently began a vast investigation programme on a group of Egyptian coffins of Theban provenance dating to the first millennium BC, primarily the 25th-26th Dynasty (c. 746-525 BC). Herein, we present the results of the multidisciplinary investigation carried out on one of these coffins before its restoration intervention: the anthropoid wooden coffin of Un-Montu (Inv. MCABo EG1960). The integration of radiocarbon dating, wood species identification, and CT imaging enabled a deep understanding of the coffin's wooden structure. In particular, we discuss the results of the tomographic investigation performed in situ. The use of a transportable X-ray facility largely reduced the risks associated with the transfer of the large object (1.80 cm tall) out of the museum without compromising image quality. Thanks to the 3D tomographic imaging, the coffin revealed the secrets of its construction technique, from the rational use of wood to the employment of canvas (incamottatura), from the use of dowels to the assembly procedure.

Keywords: X-ray tomography; egyptian coffin; in situ analysis; non-invasive investigations; radiocarbon dating; wood identification.

Figure 3

Tomographic acquisition set-up: on the left, the layout of the CT facility; on the right, the tile-scanning grid used to collect the entire tomographic data sets.

Figure 4

The results of the ¹⁴C dating: in blue, the calibration curves (plus and minus one standard deviation); in red, the radiocarbon date; and in grey, the calibrated date.

Figure 5

(a) 3D rendering of the sides of Un-Montu’s coffin and (b) visualization of its planks on each side.

Figure 6

3D rendering of the underside of the floor board: in green, the four dowels joining the two planks.

Figure 13

(a) Sagittal sections of the feet and pedestal showing the connecting dowels; (b) the wooden small planks that complete the front of the pedestal and the coffin sides with related dowels; (c) the planking of the foot board.

Figure 14

The 3D rendering of the opened coffin (left) and analysis of its closing system with the eight tenons virtually extracted (in purple).

Figure 17

(a) The incamottatura covering face and ears (highlighted in pink); (b–d) a few examples of the incamottatura no longer adhering to the wooden planking surface (highlighted in red).

Figure 18

(a) The modern restoration interventions of the underside of the floor board, (b) foot board, and (c) beard.

Figure 19

Axial sections showing the joint of the left and right side planks to the floor board by means of numerous dowels (in yellow). The arrow indicates the insertion direction of the dowels.

Figure 20

Axial sections showing the joint of the left and right side planks to the front of the lid by means of numerous dowels (in yellow). The arrow indicates the insertion direction of the dowels.

Figure 22

The dowels cut at the division of the coffin in the head wall (a), legs (b), foot board (c), and feet (d).

Figure 1

Inner and outer sides of Un-Montu’s coffin (Inv. MCABo EG1960).

Figure 2

Head end/wall and foot board of Un-Montu’s coffin.

Figure 7

3D rendering of the front of the lid: in green, the numerous dowels joining the four planks.

Figure 8

Axial slice showing the small insert with a triangular section.

Figure 9

(a) The two splayed piths in the wooden block of the face; (b,c) face, ears, beard, and wig’s lappets joined by means of glue, plaster-like materials, and dowels.

Figure 10

(a) Axial slice showing the matching growth rings of the side planks; (b) partial detachment of the growth rings, ring-shake (indicated by the orange arrow).

Figure 11

3D rendering of the left side of the coffin, lid, and box. In green, the numerous dowels joining the planks.

Figure 12

(a) The dowels connecting the three planks of the head wall; (b) axial and sagittal slices showing the cut of the central plank.

Figure 15

The stucco on the outer surface of the coffin.

Figure 16

The incamottatura on the outer surface of the coffin.

Figure 21

The traces of the handsaw on the surface of the flat edge of the box.