伊豆諸島における製炭時期とその特色

大島・八丈島・青ヶ島の事例

抄録

The author investigated the seasons for charcoal making and its main factor in the Izu Islands, and has obtained the following results:
1) The charcoal makig in the Izu Islands reaches more than 50 per cent of the annual output between December and March, and the method of production is a typical one employed in a winter season. The same kind of method is found in the mainland of Japan on the slopes of mountainous districts facing the Pacific Ocean.
2) The reason why the production of charcoal became an important industry in winter is due to the fact that the farmers have more leisure in winter in the area where the mountain slopes face the Pacific Ocean. But in the case of the Izu Islands the reasons are different in each island.
a) In Izu-Oshima island, a great deal of charcoal is made in winter (from November to March) because during this season a number of settlers come from Yamagata Prefecture to do the job of charcoal making. This practice is very rare in other parts of Japan. b) In Miyake island and Hachijo island, charcoal making is done by using the leisure hours of both farmers and fishermen. Particularly it is done in the interval (from November to February) between the gathering of agar-agar, in summer and the fishing of flying-fish in spring.
c) It is an exceptional case with regard to Aoga-shima island. Since this island suffers much from inconvenient maritime transportation, especially in winter, the suspension of steamship service is very common, and the charcoal making is done only in summer and in autumn when there is any possibility of shipment.