Abstract
In this paper the author deals with two problems of "minute shadow" which means an area bounded by a shadow curve of m-minutes and a portion of walls of a building. One is the relation between the plan of a single straight block and the critical height of the block. Another is the relation between proportions of the building and the area of "minute shadow". In any case dealt here, the long axis of a single straight block runs north and south, or east and west. Moreover, the shadow curves in this study are made from shadows cast by a building at the winter solstice in Tokyo (Lat. 35°41'N). The results are as follows (1) The critical height of the building is decided by aspect ratio of the plan. (2) The area of "minute shadow" of the building is decided by both aspect ratio of the plan and ratio of slenderness of the elevation.
