• Index of this issue

No. 57, November 2006 Special topic: Rare Books and Their Management

1. Rare Book Collection of the National Diet Library

The Rare Books and Old Materials Room of the National Diet Library (NDL) provides readers with access to about 300,000 items of the NDL's rare and old book collections, including Japanese books issued during/before the Edo period (1603-1867), Japanese colored wood block prints (Nishikie), Chinese books issued during/before the Qing dynasty, and Western books called "Ranjo" (Dutch books) which were once owned by the Tokugawa Shogunate. The NDL inherited most of its rare and old book collection from its predecessor, the Imperial Library. The NDL has designated the most precious of these as "rare books" or "semi-rare books" to be given much more careful preservation treatment than the other old books so that those treasures will be passed down to future generations.

2. Criteria for Rare Books Designation

The criteria for designation of rare books are defined by the library's internal regulations. Nominated books are sent to the Committee on Designation of Rare Books to determine which should be taken into the categories of rare/semi-rare books. Up to now, 1,220 titles have been designated as rare books and 782 titles as semi-rare books. The following are the Criteria for Rare Book Designation:

1. Japanese materials: items printed/hand-copied during/before the Keicho period (1596-1615)
2. Chinese materials: items printed during/before the Zhengde period of the Ming dynasty (1505-1521) or hand-copied during/before the Ming dynasty.
3. Western materials: items printed during/before the 16th century
4. Materials which do not fit the above criteria can also be designated as rare books for their rarity.

3. Rare Book Stack

To preserve our rare/semi-rare books, the NDL built a special storage space in the stacks, called "Rare Book Stack." The Stack was completed in February 1993 on the seventh floor below ground level of the Annex Building (approximately 24 meters underground). The features of the Stack are as follows:

1. Total floor area: 18m × 14m = 252m²
2. The air pressure in the Rare Book Stack is kept higher than that outside so that the outside air, which may include dust and dirt, will not come into the stack when the door is open. 
3. The floor, ceiling, and walls of the Stack are covered in hinoki (Japanese cypress) plywood. 187 bookshelves are made of nara (oak). Wooden trolleys are used in the Stack to deliver the materials.

(left) Rare book stack
(right) Wooden trolleys are used in the Stack to deliver the materials.

4. The air-conditioning system of the Stack is independent of the other parts of the stacks. It runs for ten hours a day to keep the temperature at 22ºC±2ºC and the relative humidity at 55%±5%.
5. In the Stack, we use UV protection fluorescent lights and try to be careful to turn off the lights when leaving.
6. Most of the materials stored in the Stack are old Japanese and Chinese materials which should ideally be stored in a horizontal position. So we shelve all the materials horizontally on the shelves in the Stack.