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TheStabilityoftheTombofNefertari1904-1987.pdf

The Stability of the Tomb of Nefertari 1904-1987 Author(s): K. M. Wilson-Yang and George Burns Source: Studies in Conservation, Vol. 34, No. 4 (Nov., 1989), pp. 153-170 Published by: Taylor & Francis, Ltd. on behalf of the International Institute for Conservation of Historic and Artistic Works Stable URL: https://www.jstor.org/stable/1506283 Accessed: 14-05-2020 10:00 UTC

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THE STABILITY OF THE TOMB OF NEFERTARI 1904-1987

K. M. Wilson-Yang and George Burns

Abstract-The conservation of the tomb of Nefertari

(No. 66, Valley of the Queens, Egypt) has attracted international concern for many years. However, pre- vious assessments of the stability of this complex physicochemical system have been neither compre- hensive in content nor unanimous in conclusions.

Here, using available photographic and diagrammatic documentation from 1904, 1921, 1942, 1971 and 1987, these assessments are examined and mechanisms of deterioration are explored. It has been found that although some paint and plaster loss had occurred in the tomb of Nefertari prior to its discovery in 1904, additional large losses appeared between 1904 and 1971. Degradation in the upper tomb levels is less extensive than in the lower tomb levels. In the tomb as

a whole, loss of large areas of both paint and plaster strata has slowed at least since 1971 and probably earlier. However, paint layer deterioration in the form of flaking has been continuous even when the tomb was closed. The pattern and physical characteristics of loss have shown that there are five interacting factors which underlie the deterioration of the tomb of Nefertari. Two intermittent but catastrophic factors operate over a short period of time: direct entry of flood-waters and the capillary absorption of trapped flood-waters into the tomb walls. Flood-waters cause immediate mechanical losses and absorbed waters induce morphological changes in the wall paintings. Absorbed waters contribute to the slower action of a third deterioration factor, sodium chloride. Salt and water movement and the eventual deposition of salt as micro- and macrocrystals throughout the painting substrate and surfaces undermine their structural sta-

bility. The chemical dehydration and associated instability of the tomb plaster is a fourth factor. This dehydration is suspected to be primarily the result of a very dry pre- or post-flood environment within the tomb. The mechanical damage caused by salt crystal growth in the friable plasters is one way that sodium chloride interacts with the plaster. Sodium chloride is suspected also to have accelerated the process of loss of chemically-bound water. The tomb materials, salt and water interact in another, previously unrecog- nized, slow process which is responsible for some paint flaking. This flaking is consistent with the inter- action of the painted layer with a fifth factor: air humidity and its fluctuations. A four-stage, long-term

conservation scheme is suggested in this paper. It involves the climatic and physical isolation of the orig- inal, the consolidation of the walls, and the construc- tion of a replica tomb.

1 Introduction

The kinetic investigation of slow deterioration processes in archaeological systems in situ is important in conservation science and archae- ological chemistry [1]. This paper deals with one such system, the tomb of Nefertari, Egypt, and presents an assessment of the macroscopic changes which have taken place in this tomb from its discovery in 1904 [2] to 1987. Such an assessment is necessary for the identification of mechanisms of deterioration at this site as well as

for long-term conservation planning for the site as a whole.

The tomb of Nefertari (No. 66, Valley of the Queens, c. 1240 B.c.) has been recognized as one of Egypt's most valued artistic treasures. Not only is it the tomb of Ramesses II's favourite queen, for whom the Temple of Hathor at Abu Simbel was constructed, it also contains some of the best examples of nineteenth-dynasty wall paintings. This tomb and its Egyptological and artistic content have been described elsewhere [2, 3].

The wall paintings in the tomb of Nefertari are carved in relief and skilfully painted in colours which still retain their remarkable brightness. The tomb is constructed on two levels (Figure 1): an upper set of chambers, and a lower set of chambers at a depth of approximately 10m, con- nected by a stairway. The lower chambers are centred around the sarcophagus room, which is supported by four columns. The Valley of the Queens lies approximately 100m above the allu- vial plain of the River Nile [4]. It is probable, based on a geological survey of the Valley of the Kings [4, 5], that the tomb of Nefertari was cut in ancient limestone landslide deposits on top of limestone interbedded with underlying expan- sive Esna shale.

The tomb of Nefertari has been the subject of Received 4 October 1988

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K. M. Wilson-Yang and George Burns

Fig 7 Fig 2

-Fig 3 Fig 8

Fig 5 0 m 5

Fig 6 / Fig 4 N

A B

0 m 5

Figure 1 Plan of the tomb of Nefertari, after reference [3]. The positions of the mural paintings which are reproduced in this paper are marked with bold lines and numbered according to the respective figures.

concern to the Egyptian Antiquities Organi- zation (E.A.O.) and to the international com- munity [1, 3, 6-10, 13] because of its structural fragility. The plaster has, in many places, lost

both cohesion and adhesion. The plaster layer, which in some places is as thick as 5cm, forms the substrate on which the murals were carved, coated with a thin white wall preparation [9] and

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The stability of the tomb of Nefertari 1904-1987

then painted. The calcium sulphate dihydrate component of the plaster, which is its binding agent, has completely dehydrated to anhydrous calcium sulphate [1, 6, 9, 11] and the plaster as a whole contains significant amounts of sodium chloride dispersed at the submicroscopic level, as found through a series of sensitive chemical analyses [1, 11]. Furthermore, the plaster sub- strate is riddled with sodium chloride crystals [1, 6, 12-15], from the microscopic to several cubic centimetres in volume, and sodium chloride efflorescence products appear on the painted surfaces.

The limestone from which the tomb was cut is

highly jointed [12, 13] and contains geological deposits of sodium chloride in the form of veins and pockets [1, 6, 13]. Movement of sodium chloride is possible in such a system and would proceed either under the action of relatively rare climatic events, e.g. sudden rainfalls or floods, or by the more insidious and continuous action of atmospheric moisture and, to a much smaller degree, groundwater.

The problems of isolation, accessibility and stability of the tomb of Nefertari have not been well understood. However, it has been possible to consider the tomb as a physicochemical sys- tem [1, 6] in interaction with its geological [12, 13] and climatic [1] surroundings. Such an approach has been useful when applied to the Temples of Karnak [16], and is applicable throughout'Egypt and elsewhere [1].

2 Descriptions, assessments and documentation

In 1904, at the time of excavation, the damage in the tomb was described: 'because of the many infiltrations of rain-water which had penetrated in between the rock and the layer of stucco, the latter had fallen in some parts and in others was about to fall, making it necessary that our work of consolidation be well devised and patient; this work was directed by Professor Fabrizio Lucarini, who was with our Mission' [2]. It was said also that, despite their state of disrepair, the scenes on the walls remained about two-thirds

intact [2]. It is significant that the appearance of salt on the painted surfaces, which is prominent now, was not reported in 1904.

The task of providing an assessment of the stability of the tomb of Nefertari after 1904 was complicated by its chemical, physical and geo-

logical diversity. Opinions on the extent and rate of deterioration vary considerably from one group to another. It was reported in 1942 [7] that 'the tomb of Queen Nefertari can be cited as an example of (this) rapid destruction'. In describing the damage it was asserted, but not supported by direct evidence, that 'the coating (plaster) soaked by humidity swells and becomes detached from the wall... the swelling becomes accentuated, the coating (plaster) caves in, frag- ments after drying and falls' [7] and paintings were seen to be 'extensively invaded by salt which deposits as blackish-grey scabs on the col- our' [7]. Shortly after 1942, access to the tomb was restricted; it had previously been a well- known attraction and was described in early guidebooks [17, 18]. A UNESCO/ICCROM committee visited the tomb in 1958 and 1969 [19] and, in 1970, it reported that 'even in places where the plaster is dangerously detached from the rock wall, no important losses could be found on comparing the original with the pic- tures taken in 1904' and also '...the tomb does not appear to have undergone any further deteri- oration of significance. Its present condition may therefore be regarded as stable' [8]. It was stated in 1974 that 'on comparing the present state of the ......paintings with these pictures [Schiaparelli's, of 1904] they do not appear to have undergone any significant deterioration since their discovery' [9]. In 1982, it was reported that the tomb had changed little between 1971 and 1977 and between 1977 and 1981 [6]. At the other extreme, it has been said that 'since the discovery of the tomb, its condition has suffered considerably...' [3] and also 'the tomb has suffered notably since its clearing eighty-three years ago' [20]. This underlying dichotomy has been recognized by the Egyptian Antiquities Organization which has stressed that 'with present facilities... this claim [of ref. 8] can be quantified' [19]; subsequently, a record of the 1987 status of the visual deterioration of the tomb of Nefertari has been compiled [21]. How- ever, this 1987 status report appears to have been prepared primarily as a guide for conservators engaged in in situ protective consolidation and does not deal explicitly with past rates of deteri- oration.

In the present paper, the deterioration of the tomb of Nefertari is examined using available supporting photographs and diagrams from

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K. M. Wilson-Yang and George Burns

1904 [2], 1920-22, 1942 [7], 1971 [3] and 1987 [10].

In 1904, at the time of excavation, an incom- plete set of photographs was made and repairs were done [2]. The quality of the photographs is variable but they are irreplaceable for the estab- lishment of major post-1904 losses.

During the 1920-21 and 1921-22 seasons, the Metropolitan Museum of Art Graphic Expedi- tion made an extensive photographic record of the tomb of Nefertari. The photographs reproduced here are reprinted from contact prints made from the original 8" by 14" glass negatives from the archives of the Metropolitan Museum of Art. Coloured copies of three scenes from the upper chambers were painted at about the same time [22]. However, a careful com- parison of the 1921 photograph in Figure 6 and the copy of the same scene [22] indicates that the painting is based almost exactly on the 1920 pho- tograph and therefore does not constitute a sep- arate source. It is reasonable to assume that this

is also true for the other two painted scenes. In 1942, photographs of extensively damaged

sections in the lower chambers were made, and a set of diagrams was published which showed areas of loss and potential loss of most of the

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The stability of the tomb of Nefertari 1904-1987

Figure 3 Nefertari before the First and Second Door of the Domain of Osiris. (a) 1921. Photography by the Egyptian Expedition of the Metropolitan Museum of Art, all rights reserved. (b) 1942 [7]. (c) 1971, from [3].

upper rooms and some of the stairwell [7]. The areas of potential losses were investigated: '... auscultation of these paintings and some probing reveals large zones of coating (plaster)

detachment' [7] and these zones appear as the hatched areas on the diagrams. Areas of loss noted in the same diagrams were described as 'large fragments [which] already have fallen since the opening of the tomb' [7]. We have found that these diagrams are not exhaustive; many small, unrepaired losses seen in the 1904 photos were not noted. Inaccuracies exist in the diagrams: some losses present in 1904 are erroneously described as being post-discovery in the 1942 diagrams. Nevertheless, the 1942 diagrams are a valuable source and represent the first use of condition diagrams in the tomb of Nefertari. Any true post-1904 losses have been verified below by comparison with later photographs.

In 1971, the first colour documentation of the tomb of Nefertari was made [3]. This publication provides a photographic record coupled with the architectural plan and documents the tomb surface, excluding most of the ceiling.

Several colour photographs were reproduced in 1987 [10]. These photographs are primarily illustrative and were not meant as a complete 1987 documentation of the tomb.

It is perhaps surprising that a comparison of all these sources has not been made before. The

reason for this appears to be that the documents cited above do not represent a continuous body of work. The 1904 excavation report [2] was con- cerned primarily with the great Egyptological significance of the site; photographs taken in 1920-22 were never published and the 1942 paper [7] was the first conservation-related docu- ment to appear in the literature. The 1971 docu- mentation followed a hiatus in published work of approximately 31 years. However, this work was not directed intrinsically toward conser- vation. The most recent document, the 1987 report [10], is oriented specifically to conser- vation studies in the tomb of Nefertari and not to the rates of deterioration.

The tomb plan given in Figure 1 indicates the location of the photographs and diagrams reproduced here.

3 Comparisons

3.1 Evidence for general post-1904 deterioration Paint and plaster losses occurred throughout the tomb after 1904. A specific example is given in a series of photographs of Nefertari adoring Hat- hor (Figure 2). This panel is found on the north

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K. M. Wilson-Yang and George Burns

wall of the lower small east chamber. The 1904, 1921 and 1971 photographs of this scene all show areas of loss, especially in Hathor's body. Although most of the losses occurred before 1904, by 1921 one can see the beginnings of further losses of painted detail between the two figures. There was some reinforcement of the paint and plaster layers around the edges of the losses: in the offertory flowers and in Nefertari's abdomen, for example. By 1971, there had been a steady loss of fragments in all regions of this panel. Most of these subsequent losses were replaced by blank infill repairs made after 1921.

3.2 Evidence for accelerated deterioration 1921-42

The photographs of the south-east wall of the sarcophagus room (Figure 3) show that dra- matic and extensive losses in all figures in this panel had occurred between 1921 and 1942. The

lower right quadrant of this panel is especially damaged. Losses which occurred between 1942 and 1971 in the panel of Figure 3 are difficult to see because of the quality of the 1942 photo- graph; they are minor in comparison with those which had occurred in the years between 1921 and 1942. Initial repairs to this wall painting were done before 1921; plaster drips can be seen in the dado of Figure 3a. Additional repairs and cleaning were performed before the 1942 photo- graph was taken.

3.3 Evidence for progressive deterioration in the upper tomb levels It has been observed that the lower chambers of

the tomb have more losses than the upper cham- bers [3, 6, 8, 12] and Figures 2 and 3 indicate that these losses have been, in part, progressive since 1904. However, in the upper part of the tomb the rate of deterioration has been progressive since

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The stability of the tomb of Nefertari 1904-1987

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discovery. This point is illustrated by Figures 4 and 5. Figure 4 shows Isis and Re-Harakhty from the east wall of the hallway to the upper east chamber. A clear pattern of damage and repair from 1904 to 1971 emerges from the photographs of this panel. In 1904, losses in the headdress of Isis had already occurred. Losses can also be seen in the plinths of Isis and Re- Harakhty, in Re-Harakhty's thigh and chest by his bent arm, and in the dado panel under the plinths. By 1921, losses in the headdress had grown. In 1942, this damage was not recorded; it is possible that it had been repaired before 1942. However, the 1942 diagram does show more extensive losses in the Re-Harakhty plinth, in Re-Harakhty's elbow and chest and in the left hand of Isis. It is likely that this 1942 diagram was used to guide repairs: the 1971 photograph shows where most of the damage noted in the 1942 diagram was infilled and repainted. From 1971 to 1987 there has been no apparent loss (see

reference [20], figure 4). Figure 5 shows Isis and Nephthys (right) from

the large west panel in the upper part of the stairway. It also shows a pattern of loss and repair. A large patch of the headdress of Isis had fallen between 1904 and 1921 and, as in Figure 4 above, was apparently repainted before 1942. Figure 5 also provides evidence of continuous deterioration which resulted in losses between

1942 and 1971. In 1904 and 1921, the feet of Nephthys could be seen. In 1942 her feet were recorded as part of an area of plaster detach- ment. By 1971, the loss in this area had not only occurred but had been repaired. In 1921 the face of Nephthys had not lost its paint layer (the light patch on the 1904 photograph is due to uneven lighting), and no loss was noted in 1942. But by 1971 the paint layer had been damaged. No additional losses to this panel were noted in a 1987 diagram [21].

None of the losses in Figures 4 and 5 has been

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K. M. Wilson-Yang and George Burns

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as great as the pre-discovery losses and the losses between 1921 and 1942 in the sarcophagus room painting shown in Figure 3.

3.4 Evidence for continuous paint layer loss A more subtle change which has occurred in the tomb of Nefertari is paint layer loss not obvi- ously associated with plaster loss. This change is exemplified in Figures 6 and 7. Figure 6 com- pares the 1921 and 1971 [3] photographs of a detail of an upper chamber wall showing a phoe- nix (also identified as a heron [22]) and the god- dess Nephthys as a hawk (or kite [22]). Enlargement of paint layer losses in the tail and wing of Nephthys are seen in the black outline of the feathers in the 1971 photograph. In Figure 7, the face of Isis (right) from a column in the sarcophagus chamber shows the enlargement of paint layer loss, especially in the pupil of the eye, which has occurred between 1921 and 1987.

Losses in the eyebrow and over the corner of the

mouth became enlarged between 1971 and 1987. Although apparently unreported, these types of losses were recognized: the paint loss seen in 1904 and 1921 on the face of Isis near her mouth

was repaired sometime prior to the 1971 photo- graph.

3.5 Evidence for stable areas in the tomb The two photographs in Figure 8 are of the god- dess Ma'at in the lintel of the doorway leading to the sarcophagus chamber. Although paint layer losses had occurred in the centuries preceding discovery, there is no evidence of change between 1904 and 1971. Furthermore, no change could be seen in a 1987 photograph (see refer- ence [20], figure 3) of this panel.

3.6 Evidence for periodic human intervention since 1904

In every group of photographs in this paper, except Figure 8, there is evidence of some human

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The stability of the tomb of Nefertari 1904-1987

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intervention. There were at least three sets of repairs between 1904 and 1987. Schiaparelli directed repairs [2] which may or may not be identical to the pre-1921 repairs (Figures 2b, 3a and 6a). Repairs were done before 1942 (Figures 3b, 4c and 5c). Some of these latter repairs may be datable. For example, in 1977, in the lower level of the tomb, a fragment of repaired painted plaster was found by one of us (GB); it had been backed with a piece of newspaper dated 1935. Finally, Figures 4d and 5d provide evidence that work was done in the tomb between 1942 and 1971.

4 Discussion

4.1 Effects offlood-waters The lower level chambers of the tomb of Nefertari have undergone the most damage, for which groundwater, rain-water and flood-water may be responsible. Groundwater is likely to play a minor role at this site because of the great

depth of the water table in desert regions and the shallowness of the tomb: the tomb is situated approximately 2km from irrigated fields and is only about 10m in depth (see Figure 1). Seepage of rain-water solely in the lower levels is not supported by observations. Although the tomb ceiling has lost some paint and plaster in the upper level as well as in the lower level, there is little difference in the extent of losses between the

two levels. That the ceiling remains largely intact suggests that seepage could not have been important. However, direct entry of waters from torrential rains is possible, especially if the door- way is not sealed. The flow of water near the base of the walls, and its entrapment in the lowest levels of the tomb, may account for the large losses in those areas. The painted dado panels on the walls of the lower chambers and, to a lesser extent, those of the upper walls, have suffered losses; in the northernmost small chamber, beyond the sarcophagus room (see Figure 1), only approximately one quarter [3] of the wall

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K. M. Wilson-Yang and George Burns

paintings remain. The upright sides of the recessed floor of the sarcophagus chamber have no decoration [3], so that flooding probably occurred to a maximum depth of about two thirds of a metre, that is, the height of these sides.

Flood damage in the tomb of Nefertari could have resulted from one or a very few floodings. The tomb of Seti I, in the Valley of the Kings, was excavated in the 1816-17 season and by 1819 water had entered and caused damage in the entire tomb [4]. The damage in the tomb of Nefertari which was noted in 1904 suggested that it was flooded before discovery [2], which is possible only if water seeped through the rubble in the entranceway.

The tomb was not adequately documented in 1904 [2] and a complete documentation was made only in 1971 [3]; therefore any flooding which resulted in the post-discovery damage in the lower level probably occurred before 1942 (see section 3.2) and certainly before 1971. The most recent reported flood in the Valley of the Kings was in 1916. The Valley of the Queens has a different drainage pattern than does the Valley of the Kings, as assessed from aerial photo- graphs [12] and topographical maps [4]. How- ever, it is probable that the Valley of the Queens, because of its proximity to the Valley of the Kings, also experienced its most recent water damage in 1916. It is known also that torrential rainfalls occurred in the entire Theban Necropo- lis yearly from 1906 to 1910 [4]. Thus flood-water

seems to be the most important factor responsible for the major losses in the tomb.

4.2 Effects of absorbed water In addition to any mechanical damage caused by flowing waters, trapped water will rise by capil- lary forces through the porous wall-painting substrate and between the substrate and the limestone walls. Therefore, murals above the flood level in the lower chambers would have been severely damaged. Some of these murals have indeed collapsed, including those in the northernmost chamber beyond the sarcophagus room, while others needed immediate repair [8]. In 1942, the swelling and subsequent drying of the plaster substrate was proposed as the mech- anism responsible for large post-discovery losses in the tomb [7]. Humidity was cited as the cause of the swelling; it is more likely, given the proba- bility of the direct entry of water as recently as the first two decades of this century, that any swelling or change in morphology was due to

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The stability of the tomb of Nefertari 1904-1987

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Figure 7 Nefertari and Isis (right). (a) 1904 [2]. (b) 1921. Photography by the Egyptian Expedition of the Metropolitan Museum of Art, all rights reserved. (c) 1971, from [3]. (d) 1987 [20]. Photo credit: Guillermo Aldana, courtesy of the Getty Conservation Institute.

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K. M. Wilson-Yang and George Burns

Figure 8 Ma'at. (a) 1904 [2]. (b) 1971, from [3].

absorbed water. Thus, capillary action in the flooded tomb appears to be the second most important factor responsible for its deterio- ration.

4.3 Effect of sodium chloride As absorbed water moves to the drier surfaces of

the murals, it will carry with it the sodium chlo- ride which is known to exist in the limestone

walls. Sodium chloride has been deposited on the painted surfaces and has also recrystallized beneath the surfaces and within the painting sub- strate, wherever its solubility has been exceeded. In itself, the occurrence of sodium chloride in the tomb is evidence of past movement of water, because sodium chloride microcrystals are dis- persed throughout the plaster and painted sur- faces. The large macrocrystals (approximately, lcm3) which have formed in the plaster and which protrude from parts of the ceiling are also evidence of water movement. Macrocrystal for- mation could not have proceeded in the same manner as that of the microcrystals but would have involved a much slower process of crystal growth. The growth of both micro- and macro- crystals in the plaster and paintings in the tomb undermines the structural stability. Pervasive microcrystals destroy the structure and cohesive- ness of plasters and paintings; growing macro- crystals lift entire fragments of murals [6, 12] and thus contribute to their collapse.

No report of observable salt was made in 1904 [2]: this negative evidence suggests that either salt microcrystals were overlooked in 1904, or salt and water movement was the result of

flooding after discovery. However, salt macro- crystals could have been formed only over a long period of time and must predate the discovery of

the tomb. A preliminary on-site geological sur- vey [12] indicated that there is an increase in sodium chloride to the depth of the tomb within the limestone rock-wall.

It can therefore be concluded that sodium chloride is a third factor which contributes to the deterioration of the tomb of Nefertari.

4.4 Effect of overall tomb humidity and its fluctuations Although flooding would have contributed to catastrophic deterioration in the tomb, its effects would have been important over only a short period of time: the tomb was cut out of poor quality limestone so that drainage of flood- waters would have happened relatively quickly, perhaps in a few weeks or months. Disap- pearance of flood-waters absorbed in the walls and the concurrent movement of salts would

have taken a longer period of time. We estimate that in the closed tomb this latter process may have taken place over several years: the losses in the lower chamber walls between 1921 and 1942

(see Figure 3) may be a result, at least in part, of the movement of absorbed flood-water. How-

ever, for most of its 3200-year existence the tomb had an internal environment which was charac-

teristic of the hot, dry, desiccated state of the desert around it. The lack of ancient Arabic or

Coptic graffiti, common in many tombs used as shelters, has been cited as evidence for the inhos- pitable nature of the internal climate [1].

The internal long-term climate and especially the air htimidity of the tomb would also affect the stability of the painted surfaces. The surface layer includes pigment, the preservation of which is of primary concern, binding media, air- deposited material and effloresced sodium chlor-

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The stability of the tomb of Nefertari 1904-1987

ide. The dominance of sodium chloride on the

surfaces of some pigment samples has been reported [15]. Both pigment and sodium chloride adsorb water at fairly low relative humidities. Pigments such as the natural reds and the char- coal blacks adsorb between a few percent and several tens of percent by weight of moisture at 50-90% RH and 30'C [23]. The relative humidity at which a monolayer of water forms on crystals of sodium chloride is between 7% and 17% RH at 230C [24] and in glass saturated with sodium chloride, measurable adsorption of water begins at < 20% RH at 22'C [25].

The internal humidity of the tomb, even while closed, reflects changes in external humidity [1]. In March, the internal tomb humidity is 4-3 + 0.4gH20/m3 (16% RH at 280C) and the corre- sponding average humidity in the Nile Valley at

the nearby Temples of Karnak is 6 + 2gH20/m3; in September the internal tomb humidity peaks at 9-1 + 0-2gH20/m3 (31-9% RH at 280C) and at Karnak the average humidity has been found to be 11 + 2gH20/m3. The overall humidification of the Nile Valley [1, 6] has proceeded since the construction of dams at Aswan, especially of the High Dam, and the effects of local changes in climate may directly affect the tomb. Fluctu- ations in internal humidity would induce the adsorption and desorption of water as well as the migration of salts to the painted surfaces.

Although the loss of large portions of paint and plaster decelerated in the closed .tomb after 1942, paint layer loss apparently continued. Paint flaking can be seen in both the upper and the lower chambers (?ee Figures 6 and 7) and in areas of apparent stability (Figure 8). Paint flaking appears to be currently active in the dry, unflooded and rarely visited tomb. The progressive and continuous nature of paint flaking in the tomb of Nefertari has not been recognized previously. Therefore, air humidity and its fluctuations appear to be the fourth fac- tor contributing to the deterioration in the tomb of Nefertari.

4.5 Dehydration of plasters For most of its history the tomb existed in a desiccated state and, primarily because of this stable, dry climate, all of its gypsum-based plas- ters gradually lost their waters of crystallization [1, 11]. As a consequence, the plasters also lost their binding properties [1, 11]. This has resulted

in yet another serious instability in the tomb and is the fifth cause of its deterioration.

4.6 The interrelationships among various deteri- oration processes The five factors outlined in this discussion do not

necessarily act independently but may affect and accelerate each other. Flood-waters caused immediate mechanical losses and also were the source of water which was absorbed into the walls. The dissolution, movement and recrystallization of sodium chloride is a con- sequence of the movement of water through the plaster and painted surfaces. The loss of chem- ically bound waters in the painting substrate appears to be accelerated by the sodium chloride dispersed throughout the gypsum-based plaster [1, 11]. Furthermore, the adsorption and desorp- tion of air moisture, which occurs as humidity fluctuates, causes solution and reprecipitation of surface-deposited sodium chloride. The induced salt damage at the surface, analogous to that which has occurred within the plaster and walls of the tomb, appears to be responsible, in part, for paint flaking.

4.7 Long-term conservation All the deterioration processes described above continue to endanger the tomb of Nefertari. The potential for flooding and the involvement of the fluctuating climate in the tomb still require detailed, site-specific surveys and assessments as to their degree of influence. However, it is evi- dent from the preceding discussion that they have serious implications for its future stability, and flood and climate control must be addressed

in the long-term conservation of this site. A suggested conservation scheme for the tomb

of Nefertari can be conceived in four stages. The first stage involves the construction of tempo- rary, non-invasive protection from floods and rainfall. This would remove the potential for the two most destructive processes leading to rapid deterioration; a single flood could mean irrevo- cable destruction in this fragile tomb. The other three long-term processes of deterioration can then be addressed. Initially, it is necessary to remove the dust in the tomb, especially on the floors where in places it lies in thick layers. The key element in the second stage is the installation of a climate control system to stabilize the tomb climate at its internal temperature and humidity

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K. M. Wilson-Yang and George Burns

when closed. The tomb would thereby be protec- ted from potentially non-reversible climatic changes and assured of a clean, dust-free atmo- sphere. Data on the internal temperature and humidity fluctuations in the tomb have been compiled [1, 6, 8, 26] under various conditions of access. The tomb, while closed, is isothermal: the average internal temperature has been found to

be 28-5 + 0.-5C [1]. To ensure optimum stability of the tomb, its inherent temperature must be maintained by the new climate control system. However, the tomb is also a humidity sink [1]: being dry, it attracts outside moisture. There- fore, the existing minimum internal humidity in the closed tomb, supposed [1] to be 16 + 1% RH, must be maintained. However, temperature and humidity measurements made while the tomb is open, or when large groups of people are present, are deceptive because they do not repre- sent the true climate of the isolated tomb [1]. Therefore they cannot be used for the selection of optimum temperature and humidity mea- surements for the air-conditioning system.

It is essential that the climate control system be put in place as carefully and as unobtrusively as possible. Climate controls have been employed at other sites, notably in the painted caves at Lascaux [27], in mediaeval painted tombs in Bruges, and in excavated Roman struc- tures in Atri [28]. An evaluation of these existing systems would be instructive in the imple- mentation of climate controls in the tomb of Nefertari.

Once protected from floods, dust and climate fluctuations, the third stage, i.e. the reversible consolidation and repair in the tomb itself, can proceed more safely and more thoroughly. This stage should proceed under the guidance of wall painting specialists.

As the fourth stage, permanent flood manage- ment, the construction of a protective per- manent superstructure and any structural modifications needed to increase the isolation of the tomb should be considered. Flood manage- ment has been recommended [5] for many tombs in the Valley of the Kings; after proper assess- ment, a flood management scheme for all tombs in the Valley of the Queens could also be desirable.

Once all four stages are completed, the tomb will become accessible to a number of specialists. Unlimited access by tourists may still be inadvis-

able: as well as making the tomb prone to occa- sional vandalism, large numbers of passers-by would contribute to fluctuations* in humidity and thereby to renewed salt migration. Since deterioration from these latter sources is cumu- lative, it cannot be tolerated. For this reason, as the long-term conservation of the tomb is pro- ceeding, a replica should be constructed. This would allow visitors to see the essential details of the tomb of Nefertari without entering the tomb itself. This alternative is not unprecedented: the painted caves of Lascaux have been replicated and the original site is closed [27].

This scheme is proposed to continue the discussion [1, 7, 8, 10] of the conservation of the tomb of Nefertari and other threatened sites in the Nile Valley. As described in this scheme, long-term conservation treatments and emer- gency treatments would proceed concurrently; to this extent the scheme could be considered radical. To date, conservation efforts at the tomb of Nefertari have primarily involved emergency treatment of the wall paintings [29]. Although we are not in a position to give a useful evaluation of the cost of the scheme proposed in this paper, the tomb of Nefertari is an irreplaceable monu- ment and its inherent value has already justified the labour-intensive involvement of many conservators [10, 21, 29].

5 Conclusion

The progress of deterioration in the tomb of Nefertari, based on the evidence presented in this paper, is summarized in Figure 9. This figure shows qualitatively the relationship of time and paint and plaster loss in the upper and lower levels of the tomb.

Although much damage had occurred in the tomb of Nefertari prior to its discovery in 1904t, noticeable losses appeared between 1904 and 1971 (Figures 2 and 3). Photographic evidence indicates that deterioration accelerated between

*An individual entering the closed tomb produces 0.013g H20/min at the internal tomb temperature of 280C [1].

tExpansive shale movement has been implicated in the formation of large cracks and structural collapse in tombs in the Valley of the Kings over the past 3500 years [5].

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The stability of the tomb of Nefertari 1904-1987

wO >J W LL

c -4 SUPPERLEVEL

1240 0 900 1920 1940 1960 1980

> w / -1 o 0-4

a_ w aw w

ii:::: . o00 1920 1940 1960 LEVEL

UIPPER LEVEL 1240 0 -100 1920 1940 1960 1980'

BC YEAR AD

Figure 9 Schematic graph of the progress of deterioration in the Tomb of Nefertari. The ordinate is in arbitrary units describing the extent of loss in paint and plaster layers: 0, no change; 1, losses seen on close inspection; 2, easily seen small losses; 3, major losses of important hieroglyphs and painted features; 4, massive losses of whole panels; 5, complete loss of entire painted surface and substrate.

1904 and 1942 in the lower tomb level (Figure 3) and slowed thereafter. Degradation in the upper part of the tomb is not as marked, but has progressed since 1904 (Figures 4 and 5). Never- theless, there are areas of the tomb which have remained apparently unchanged since 1904 (Fig- ure 8). This range of observations has led to the dichotomy found in previous assessments [3, 7-9, 20]. In general, degradation, in the form of large losses in both the paint and the plaster strata, has slowed at least since 1971 and proba- bly since 1942, coinciding with restricted access. However, there is evidence that paint layer dete- rioration in the form of flaking continues to the present day (Figures 6 and 7). The pattern and physical characteristics of loss which emerge from the photographic evi- dence and from the literature have shown that

there are five, in some cases interacting, factors which are responsible for the deterioration of the tomb of Nefertari. Two factors operate over a short period of time: direct entry of flood-waters and the capillary absorption of trapped

flood-waters into the tomb walls. Flood-waters cause immediate mechanical losses and

absorbed waters induce morphological changes in the wall paintings. Absorbed waters con- tribute to the slower action of a third factor, sodium chloride. Salt and water movement, and the eventual deposition of salt as micro- and macrocrystals throughout the painting substrate and surfaces, undermine their structural sta- bility. The chemical dehydration and associated instability of the tomb plaster is a fourth factor and is primarily a result of a slow process in a very dry pre- or post-flood environment. The loss of chemically-bound water is also suspected to have accelerated in the presence of sodium chloride. The continuous interaction of a fifth

factor, air humidity and its fluctuations, with the painted surfaces is apparently involved in flaking of the paint layer. This deterioration has occurred continuously in the tomb, even while access was restricted.

These conclusions have been used in this

paper to propose long-term plans for the conser-

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K. M. Wilson-Yang and George Burns

vation of the tomb of Nefertari. To improve stability, the tomb must be isolated from rain and flood run-off, and from the atmosphere. This isolation should have equal priority with the conservation [29] of the wall paintings them- selves.

The construction of a replica is offered as an alternative to the extensive conservation which

would permit visitors to enter this tomb. The construction of a replica in no way removes the need for the conservation of the original: the combined approach of climatic and physical isolation, treatment of the wall paintings and replica construction would meet the demands of both tourism and conservation.

Acknowledgements

We would like to acknowledge the Egyptian Antiqui- ties Organization which provided permits to work in the tomb of Nefertari. We are grateful to Dr Hishmat Messiha who first suggested that we study this tomb. Our discussions with the late Dr Zaki Iskander con-

siderably enhanced this project. We thank Dr Ali el Khouli, Director of Excavations, Egypt, whose dedi- cation to the preservation of Egyptian antiquities assured our continuous interest in the tomb of

Nefertari. We wish to thank the Department of Egyptian Art at the Metropolitan Museum of Art, New York, and specifically Marsha Hill, for provid- ing access to the archival collection of photographs of the tomb of Nefertari. We acknowledge the assistance of Irina Averkieff and Kelley Fitzgerald of the Getty Conservation Institute in providing the photograph used in Figure 7. Ingeborg Krentl gave permission on behalf of Akademische Druck und Verlagsanstalt, Graz, Austria, to reprint figures from Goedicke and Thausing's Nofretari, for which we are grateful. We thank Dr Anne Urbancic of the University of Toronto who translated passages from the Schiaparelli report, and Irene Vaisnoras, University of Toronto, who pro- vided an additional reading of this original document. John Glover of the University of Toronto provided indispensable advice regarding photographic repro- duction, for which we are grateful. This research has been sponsored by the University of Toronto, the Natural Sciences and Engineering Research Council of Canada, and by the Canadian Commission of UNESCO/CIDA Assistance Programme.

References

1 BURNS, G., WILSON-YANG, K. M., and SMEATON, J. E., 'Archaeological sites as physicochemical systems: The Tomb of Nefertari, Egypt' in

Archaeological Chemistry IV (Advances in Chemistry Series No. 220), American Chem- ical Society, Washington (1988) 289-310.

2 SCHIAPARELLI, E., Relazione sui lavori della missione archeologica Italiana in Egitto (1903-1922) Vol. 1, 51-104; 55, para.3; 94.

3 GOEDICKE, H., and THAUSING, G., Nofretari; A Documentation of her Tomb and its Decoration, Akademische Druck u. Verlagsanstalt, Graz, Austria (1971) 35.

4 RUTHERFORD, J., and ROMER, J., 'Damage in the royal tombs in the Valley of the Kings at Thebes', Report to the Egyptian Antiquities Organization, January 1977 (unpublished) pp. 19, 36. This report is available from Ruther- ford and Chekene Consulting Engineers, 303 Second St, Suite 800 N, San Francisco, CA 94107, USA.

5 CURTIS, G., and RUTHERFORD, J., 'Expansive shale damage, Theban royal tombs, Egypt' in Proc. 10th Intern. Conf. Soil Mechanics and Foundation Engineering, Stockholm 3 (1981) 71-74.

6 WILSON-YANG, K. M., BILLARD, T. C., and BURNS, G., 'Chemistry and physics in the tomb of Nefertari', J. Soc. Stud. Egyptian Antiquities 12 (1982) 9-11.

7 STOPPELAERE, A., 'Degradations et restaurations des peintures murales 6gyptiennes', Annales du Service des Antiquites de l'Egypte 40 (1942) 941-950.

8 PLENDERLEITH, H. J., MORA, P., TORRACA, G., and DE GUICHEN, G., Conservation Problems in Egypt, UNESCO Consultant Report, Con- tract No. 33.591 (1970).

9 ISKANDER, Z., 'Some restoration problems in Egypt and their treatment' in Recent Advances in Science and Technology of Materials, ed. A. BISHAY, Plenum, New York (1974) Vol. 3, 1-8.

10 CORZO, M. A., (editor), Wall Paintings in the Tomb of Nefertari, First Progress Report, July 1987, Egyptian Antiquities Organization and the Getty Conservation Institute, Cairo (1987).

11 SMEATON, J. E., and BURNS, G., 'The physico- chemistry of the Tomb of Nefertari, Egypt', Proceedings of the Material Research Society 123 (1988) 209-304.

12 EL BAZ, F., 'Geographical and geological setting' in Wall Paintings in the Tomb of Nefertari, First Progress Report, July 1987, Egyptian Antiquities Organization and the Getty Con- servation Institute, Cairo (1987) 46-52.

13 GAURI, K. L., 'The deterioration of ancient stone structures in Egypt' in Prospection et Sauve- garde des Antiquitis de l'Egypte, Egyptian Antiquities Organization, Cairo (1981) 17.

14 PREUSSER, F., 'First report on analysis of sam-

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ples' in Wall Paintings in the Tomb ofNefertari, First Progress Report, July 1987, Egyptian Antiquities Organization and the Getty Con- servation Institute, Cairo (1987) 82-93.

15 SALAH, A. S., 'Pigments, plasters, and salt analysis' in Wall Paintings in the Tomb of Nefertari, First Progress Report, July 1987, Egyptian Antiquities Organization and the Getty Conservation Institute, Cairo (1987) 94-105.

16 BILLARD, T. C., and BURNS, G., 'Solution of the continuity equation at Karnak', Nature 285 (5767) (1980) 653-655.

17 CAPART, J., Thibes, Vromant et Cie, Brussels (1925) 153.

18 BAIKIE, J., Egyptian Antiquities in the Nile Valley, Methuen, London (1932) 517-521.

19 KADRY, A., and ESMAEL, F. A., 'Previous endeavours' in Wall Paintings in the Tomb of Nefertari, First Progress Report, July 1987, Egyptian Antiquities Organization and the Getty Conservation Institute, Cairo (1987) 36.

20 MOUKHTAR, G., 'Archaeology' in Wall Paintings in the Tomb of Nefertari, First Progress Report, July 1987, Egyptian Antiquities Organization and the Getty Conservation Institute, Cairo (1987) 26.

21 MORA, P., MORA, L., and CAPRIOTTI, G., 'Condi- tion survey' in Wall Paintings in the Tomb of Nefertari, First Progress Report, July 1987, Egyptian Antiquities Organization and the Getty Conservation Institute, Cairo (1987) 112-123.

22 DAVIES, N. M., Ancient Egyptian Paintings, The Oriental Institute of The University of Chi- cago, Oxford (1936) Vols 2 and 3.

23 KALINSKAYA, T. V., KRASOTKIN, I. S., and SEMENOVA, E. V., 'Adsorption of moisture by inorganic pigments', Kakokras. Material. i ikh Primen. 6 (1982) 9-11.

24 RICE, D. W., and PETERSON, P., 'Salt water vapor interactions using the piezoelectric effect', J. Electrochem. Soc. 128 (1981) 1619-1622.

25 LITVAN, G. G., 'Phase transitions of adsorbates: V. Aqueous sodium chloride solutions adsorbed on porous silica glass', J. Colloid and Interface Science 45 (1973) 154-169.

26 ESMAEL, F. A., 'Microclimatic conditions' in Wall Paintings in the Tomb of Nefertari, First Progress Report, July 1987, Egyptian Antiqui- ties Organization and the Getty Conservation Institute, Cairo (1987) 64-68.

27 Vouvt, J., BRUNET, J., VIDAL, P., and MARSAL, J., 'Les oeuvres rupestres de Lascaux (Montignac, France): Maintien des conditions de conservation', Studies in Conservation 28 (1983) 107-116.

28 STANLEY PRICE, N. P., 'Preventive measures during excavation and site protection: A review of the ICCROM University of Ghent conference, November, 1985' in In Situ Archaeological Conservation, Instituto Nacional de Antropologia e Historia de Mexico and the Getty Conservation Institute, Century City, CA (1987) 71.

29 SIENA, J. S., (editor), 'Final conservation treat- ment on tomb of Queen Nefertari', The Getty Conservation Institute Newletter 3(1) (1988) 1-2.

KRISTINE WILSON-YANG, BSc (Hons) (McMaster), is a PhD candidate in the Department of Chemistry at the University of Toronto. Her current research interests include the study of archaeological sites as physico- chemical systems. She has worked in the tomb of Nefertari and the tombs at Beni Hasan, Egypt. Other scientific interests include environmental analysis, the kinetics of slow reactions, surface and solid state chemistry and methods of analysis, and applications of lasers in analytical chemistry. Author's address: Lash Miller Chemical Laboratories, 80 St George St, Toronto, Ontario, Canada M5S 1Al.

GEORGE BURNS, AM (Columbia), PhD (Princeton), National Academy of Sciences Post-Doctoral Fellow (Cambridge), is Professor of Chemistry at the Univer- sity of Toronto. His research involves the application of physical and chemical methods to archaeology. He has worked on a variety of archaeometric problems at various sites in Egypt and the Sudan. His research interests also include laser photochemistry and the- oretical chemical reaction kinetics. Author's address:

as for Wilson- Yang.

Resume--La conservation de la tombe de Nefertari (No. 66, Vallke des Reines, Egypte) est l'objet de l'attention internationale depuis de nombreuses annees. Cependant les evaluations precedentes de la stabilite de ce systeme physico-chimique complexe n'ont jamais 6t6 ni completes ni unanimes dans leurs conclusions. Dans notre cas, en employant le docu- mentation photographique ou graphique disponible de 1904, 1921, 1942, 1971 et 1987, on a examine ces evaluations et les mecanismes de deterioration. On a

trouv6 que bien que quelques manques de peinture et de pl tre aient 6t6 constates avant 1904, la plupart des grandes lacunes sont apparues entre 1904 et 1971. L'alteration dans la tombe est plus importante en bas qu'en haut. Mais dans 1'ensemble, la perte de grandes surfaces de peintures et de couches de platre s'est ralentie depuis au moins 1971 et probablement plus t t. Cependant la deterioration de la couche de pein- ture par 6caillage est restee un phenomene continu,

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meme lorsque la tombe a 6t6 ferm6e. Les contours et les caracteristiques physiques des manques ont mon- tr6 que cinq facteurs interviennent dans la d6t6rio- ration de la tombe. Deux d'entre eux sont

intermittents, mais n6anmoins catastrophiques, et interviennent pendant une courte periode de temps: il s'agit de l'invasion des eaux de crue, et de l'absorption par capillarit6 de ces eaux dans les murs de la tombe. Les eaux d'invasion sont la cause m6canique de man- ques imm6diats de peinture, et les eaux absorb6es con- duisent a des changements morphologiques des peintures murales. Ces eaux contribuent 6galement a l'action plus lente d'un troisieme facteur de d6terio- ration, le chlorure de sodium. Ainsi le sel, les mou- vements des eaux, et la deposition 6ventuelle de sel sous forme de micro et macrocristaux sur tout le sup- port de la peinture et sa surface en compromettent la stabilit6 structurelle. La d6shydratation chimique et l'instabilit6 du platre qui l'accompagne constituent le quatrieme facteur. On pense que cette d6shydratation serait d'abord le r6sultat d'un environnement tres sec avant et apr6s l'invasion de la tombe par les eaux. La d6t6rioration m6canique caus6e par la croissance des cristaux dans les platres friables est l'une des con- s6quences de la reaction du chlorure de sodium sur le platre. On suppose aussi que le chlorure de sodium accel6re le processus de depart de l'eau liee. Les mat6- riaux de la tombe, le sel et l'eau r6agissent par un autre processus lent, ignore auparavent, qui est responsable de quelques 6caillages de peinture. Ce ph6nomene est compatible avec l'intervention sur la couche de pein- ture d'un cinquieme facteur: l'humidit6 de l'air et ses variations. On recommande dans ce papier un projet de conservation a long terme de la tombe, 6chelonn6 en quatre &tapes, et qui comprend l'isolation cli- matique et physique de l'original, la consolidation des murs, et la construction d'une r6plique de la tombe.

Zusammenfassung-Die Konservierung des Grabes der Nefertari (Nr. 66 im Tal der K6niginnengriber, Agypten) zieht seit vielen Jahren die Aufmerksamkeit der internationalen Offentlichkeit auf sich. Friihere

Beurteilungen der Stabilitit dieses komplexen physikalisch-chemischen Systems waren jedoch weder inhaltlich ersch6pfend, noch einmiitig in ihren SchluBfolgerungen. Unter Riicksicht auf heute noch verffigbare photographische und gezeichnete Doku- mentationen der Jahre 1904, 1921, 1942, 1971 und

1987 wertet dieser Beitrag die bisherigen Beurteilungen aus und untersucht Zerfallsmechanismen. Dabei stellt sich heraus, daf3, obgleich bereits vor der Entdeckung des Grabes 1904 einige Farb- und Putzausbriiche erfolgt waren, zusatz- liche gro3e Ausbriiche in den Jahren zwischen 1904 and 1971 geschahen. Dabei ist der Zerfall im oberen Teil des Grabes weniger stark als in den unteren Be- reichen. Im gesamten Grab hat sich der Verlust gro3er Farb- und Putzschichten seit mindestens 1971 oder

bereits friiher verlangsamt. Kleinere Abplatzungen der Farbschichten erfolgten selbst dann, wenn das Grab geschlossen war. Eine Analyse des Scha- densbildes erlaubt die Ableitung von fiinf Scha- densfaktoren, die fiir den Verfall des Grabes der Nefertari verantwortlich zeichnen. Zwei ver-

hdingnisvolle Faktoren wirken sich periodisch fiber kurze Zeitriume aus: Die Wassereinbriiche bei Uberschwemmungen und die Kapillarabsorption des dabei gestauten, nicht abflie3enden Wassers in die Winde der Grabkammer. Hierdurch werden unmittelbar mechanisch bedingte Ausbriiche und morphologische Veranderungen in den Wand- malereien verursacht. Das absorbierte Wasser trigt zur langsameren Wirkung des dritten Faktors, des Natriumchlorids bei. Eine Verfrachtung salzhaltiger Ldsungen und das m6gliche Ausbliihen von Salz als mikroskopische oder makroskopische Kristalle tragen zur Schwichung von Putz und malerei bei. Ein Trockenfallen und damit verbunden eine

Destabilisierung des Putzes ist ein vierter Faktor, der in erster Linie durch sehr trockene Perioden vor und

nach den Uberschwemmungen verursacht wird. Als eine Mdglichkeit der schidigenden Wechselwirkung zwischen Natriumchlorid und Putz werden Salz-

ausbliihungen innerhalb des br6ckeligen Putzes angesehen. Die Gegenwart von Natriumchlorid wird vermutlich weiterhin den Verlust chemisch gebunde- nen Wassers beschleunigen. Die Materialien der Grabkammer, das Salz und das Wasser stehen als fiinfter Schadensfaktor zuguterletzt in einer bislang unerkannten, langsamen Weise derart in Wechselwirkung, da3 Schwankungen der Luftfeuchte weitere Farbausbriiche bewirken. Der Beitrag schligt ein vierstufiges Konservierungskonzept vor: Es umfal3t eine klimatische wie auch physische Isolierung der originalen Grabkammern, eine Festigung ihrer Winde wie auch den Bau einer Kopie der Grab- kammer.

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