On natural light of tea-gardens and tea-houses

Abstract

Roji or a tea-garden is the typical Japanese garden in which natural light is used to create an ideal world of shadow and light. The writer investigated the light qualities of the tea-house and Roji in order to obtain data which might be useful to create spaces for appreciation of delicate light.
Illumination was measured by means of two photometers at the same time putting one at a given place and the other at the standard point in the air. Data was obtained from five tea-houses and gardens of different style.
Results: Indoor
1) On clear middays the indoor illumination was always lower in summer than in autumn in spite of the higher outdoor illumination in summer.
2) The indoor illumination was not over 34lx when the paper sliding screens were shut on the middays.
3) The writer observed, during an actual tea-ceremony of a very authentic kind in autumn, that natural lihgt was delicately controlled with bamboo blinds hanging on sliding screens, or with a prop. This was in accordance with the rules of a classical teabook.
Results: In Roji
1) Rhythm of shadow appered in sequence, e. g. gate→resting house→large tree→wash-basin under thick shrub.
2) Relative illumination along the path was higher in autumn after trimming than in summer when foliage was fresh.
3) Consideration of light adaptation for the eye was observed at the connecting space between the Roji and the tea-house.
The writer believes that landscape architects today should be more concerned with these delicate light qualities and their subtle effect on spaces. This awareness can be seen in our traditional garden.