| ■Tokyo National Research
Institute for Cultural Properties |
■Center for Conservation
Science |
| ■Department of Art Research,
Archives and Information Systems |
■Japan Center for
International Cooperation in Conservation |
| ■Department of Intangible
Cultural Heritage |
|
Facing the first stone of the east wall (Group of Male Figures)
Removing the facing from the second stone of the east wall (Seiryu, the blue dragon)
With the dismantling and transporting of the first stone of the west wall on which is drawn a painting known as “Group of Male Figures” to the Temporary Restoration Facility on June 26, the dismantling of the stone chamber of Takamatsuzuka Tumulus that started in April 2007 has been completed with the exception of the floor stone. The National Research Institute for Cultural Properties, Tokyo is engaged in the work of conserving the wall paintings of Takamatsuzuka Tumulus, including the restoration of the paintings, biological investigation and environmental control.
The following sections of the stone chamber were dismantled and transported (in order): June 7th – the second stone of the east wall (Seiryu, the blue dragon); 14th – the second stone of the west wall (Byakko, the white tiger); 15th – south wall; 22nd – the first stone of the east wall (Group of Male Figures); and 26th – the first stone of the west wall (Group of Male Figures). The restoration team removed the plaster that covered the spaces between the stones and applied synthetic paper to the surface of the paintings in order to transport them safely. Materials needed as well as the timing for doing this work was carefully considered so as to reduce the risk of fungal growth. Moreover, every time a stone was taken out, the biology team investigated the microorganisms within the tumulus. As the stone chamber was dismantled piece by piece the environment team covered what was still left of the chamber with insulation in order to keep the humidity around the paintings stable.
Stones taken into the Temporary Restoration Facility will undergo photographing, sampling and cleaning. They will then be taken into the restoration workroom. After the facing on the surface is removed, the condition of the wall paintings will be observed and recorded in order to collect information necessary for the restoration of the wall paintings which will be conducted over a long period of time.
Observing a microscope image of the cloth binding of the original copy
Cruydt-Boeck is a herbal written by Rembertus Dodonaeus (1517-1585), a Belgian naturalist. An original copy of its second edition in Dutch (1618) was imported to Japan during the Edo period. It is known that Noro Genjo and others wrote the first herbal in Japanese from 1741 to 1750 by order of Tokugawa Yoshimune based on a translation of Cruydt-Boeck. It is also said that Ishii Toko, Yoshida Masayasu and others made a complete translation by order of Matsudaira Sadanobu in 1823.
Of the several copies of the original said to have been imported, the one in the collection of the Waseda University Library was separated into 7 volumes after being imported and then re-bound as a book. The first of the 7 volumes is being restored by Okamoto Koji, a book restorer. In the process of restoration, it was found that a very sophisticated Western style of bookbinding was used for the original copy and that there is a possibility that it is one of the oldest books made in this style in Japan. Thus, on request from Mr. Okamoto, the National Research Institute for Cultural Properties, Tokyo set off to conduct a scientific analysis of the binding materials in cooperation with other institutes in order to obtain information that will enable us to determine the period at which it was made bound. To this day, image scanning analysis by Kato Masato of the Center for Conservation Science and Restoration Techniques has revealed that paper used for a book published in France in the latter half of the 18th century was used for the inside cover. In addition, attenuated total reflection analysis by Sasaki Yoshiko of the Kyoto Institute of Technology points to a great possibility that domestic hemp was used as binding thread. Furthermore, UV-visible reflection spectroscopy by Yoshida has shown that the cloth binding, which is thought to be Jouy print, was dyed with indigo. Since the original copy is severely damaged, extreme care is taken to research the various materials. For this reason, it will require much more time before we can obtain the above-mentioned results. We hope to continue work so as to clarify the history of this original copy little by little by selecting analytical methods most appropriate for each material.
Mural paintings that have been dismantled, transported to the Temporary Restoration Facility and are waiting to be restored
With regard to the conservation of the mural paintings of the Takamatsuzuka Tumulus, it was decided in 2005, from the point of view of prevention of damage due to microorganisms, to temporarily dismantle the stone chamber and to remove the paintings for restoration. Discussions were held concerning various issues such as the method for dismantling the stone chamber and transporting the stones, method for treating the mural paintings and the stones, and the construction of a restoration facility. From April 2007, the work of dismantling the stone chamber, transporting the stones to the restoration facility and the restoration of the paintings started. The National Research Institute for Cultural Properties, Tokyo is involved in this project for the conservation of the mural paintings especially from the aspects of environmental control, biological measures and restoration of the paintings. In this month’s report, measures taken with regard to the paintings will be introduced.
Various influences that may occur to the paintings when transporting the stones from the tumulus to the restoration facility were discussed in detail.
The surface of the paintings is first reinforced by using cellulose derivatives and/or protected by using a special type of paper. Once transported to the Temporary Restoration Facility built for the purpose, the stones are cleaned in the preparation room to remove dirt and grime from the surface. Although the environment inside the facility is in a condition not favorable for fungal growth, sterilization with ethanol is also done. Once cleaning is completed, the stones are taken to their respective positions within the restoration room. Main work of the restoration of the paintings begins after the stones have been moved into the restoration room. Presently, paper applied for protection is carefully being removed. The painting surface is being carefully observed and ways of cleaning the painting surface and methods of restoration are being discussed.
As of May 31, 7 stones have been moved into the Temporary Restoration Facility and are waiting full-scale restoration.
Overview of the aid-conditioning system inside the insulation chamber
The stone chamber of Takamatsuzuka Tumulus is now being dismantled for conservation. As the excavation of the mound surrounding the stone chamber progresses, the stone chamber will become exposed to outside air and the temperature and humidity inside the chamber is expected to be greatly affected by changes in the outside temperature and humidity. In order to maintain the temperature and humidity inside the stone chamber stable, a chamber with insulation walls was constructed on the mound and measures were taken to control the air inside. Since fungal growth generally increases as the temperature rises, cooling pipes were installed to keep the temperature at 10℃ and the humidity at 90%.
To control humidity, air is passed through a scrubber, a container in which water is sprayed, and the humidity is adjusted by means of a heat converter called fancoil. Since a very small change in temperature can cause a great change in relative humidity when the temperature is as low as 10℃, the value of temperature and humidity within the insulation chamber is put into the computer and controlled by a feedback system. With regard to the control of air inside the insulation chamber, we were able to obtain the initially planned results with the cooperation of Professor Hokoi Shuichi of Kyoto University.
