Within the framework of the conservation and preservation of the Dead Sea Scrolls at the laboratory of the Israel Antiquities Authority we have considered how to store and exhibit the Scrolls1. The question arose whether the scrolls should be enclosed in completely sealed frames made of polycarbonate plates for exhibition and transportation or be placed in containers with openings for ventilation, as is widely practised. This report describes experiments carried out in order to answer this question.
For experiments 1 and 2, two kinds of frames were made, measuring 25 x 15,5 x 3 cm'1 (Fig. 1). In Frame 1, 25 evenly spaced holes of 0,7 cm in diameter were drilled; Frame 2 remained intact. A small fragment of parchment was placed into each frame, as well as a thermometer and hygrometer. The frames were placed next to each other under the same conditions until their temperature and relative humidity had stabilized.
In Experiment 1, both frames were equally elevated above die table in order to allow air circulation. The room was without strict climate control. The fluctuation in temperature and relative humidity within the frames over 15 days are given in Table 1.
In Experiment 2, both frames were placed inside a plastic container and were elevated from the bottom. Two glasses of water covered with damp cloths were put between the frames. The plastic container was hermetically sealed with polystyrene film (see Fig. 2 and 3). At the beginning of the experiment the frames had the following temperature and relative humidity:
• Frame 1:25°C, 55%
• Frame 2: 24°C, 50%
Fig. 1: Structure of the frames.
Fig. 2: A frame.
The changes in temperature and relative humidity within the boxes over 15 days are shown in Table 2.
At the end of the experiment the relative humidity inside the plastic container had reached 100%.
For Experiment 3, three new frames were made identical to the previous ones, except that in Frame 3 15 equally spaced holes were drilled of diameter 0,7 cm in order to test the effect of the number of holes. When the temperature and relative humidities in the frames had stabilised they were placed inside an electric kiln with a constant internal temperature of 40°C. As before, the changes in temperature and relative humidity inside the frames were recorded (Table 3).
These three experiments were performed in order to determine the influence of the environment on frames with or without ventilation holes, first in a room
Table 1: Climatic data of Experiment 1: Frames exposed to air circulation.
without strict climate control, second in a space with relative humidity up to 100% and third in a space of temperature 40°C. All three possibilities can occur when the climate control in the storage or exhibition hall fails or during transport or disaster.
Experiment 1 shows that the changes in temperature and relative humidity in the closed box are slight: in Frame 1 the temperature varied by 2 degrees and the relative humidity by 9%. In Frame 2 the temperature varied by 2 degrees
Fig. 3 and 4: Arrangement of the frames for experiment 2, top view and side view.
Table 3: Climatic data of experiment 3: Frames exposed to elevated temperature.
and the relative humidity by 3%. Experiment 2 reveals a dramatic difference between the two frames: in the frame with the ventilating holes the relative humidity rose by 40 % to 95%, in the closed frame it increased by 6% to only 56%. In neither frame was there a significant change in temperature. Experiment 3 demonstrates that the number of holes has an influence both on the change in temperature and the change in relative humidity. It should be noted that in the frame without holes the temperature rose as expected but the relative humidity increased by only 3%.
We conclude that exhibition and transportation frames for the Dead Sea Scrolls should be constructed completely closed to avoid biological damage and changes in the dimensions of the parchment with the risk of danger to the text2,3,4.
Exhibition and Transportation of the Dead Sea Scrolls
Experiments were performed in order to determine the effect of the surroundings on frames with or without ventilation holes, first in a room without climate control, second in a place with relative humidity of up to 100% and third in surroundings of temperature 40°C. It is concluded that exhibition and transportation frames for the Dead Sea Scrolls should be completely closed in order to avoid a change in the dimensions of the parchment.
Exposition et transport des Manuscrits de la Mer Morte
Des experiences ont ete faites dans le but de determiner ['influence du climat environnant sur le parchemin contenu dans des caisses avec ou sans trou d'aeration, ces caisses ont ete placees tout d'abord dans une piece non equipee d'air conditionne, puis dans un endroit ou le taux d'humidite relative allait jusqu'a 100% et enfin dans un environnement ou la temperature attei-gnait 40°C. En conclusion on constate que les Manuscrits de la Mer Morte ne devraient etre transports que dans des caisses absolument closes afin d'eviter toute alteration des dimensions du parchemin.