An Ethno-historical Study of Religious Buildings in the Ryukyu Archipelago : Searching for a Chronology Based on the Development of Plans of Wells Constructed with Stones

本研究拟从宗教建筑的形态特征，特别是石井的形态特征，建立一个年代框架，确定琉球王朝对主冲绳的政治控制扩散到宫古和八重山诸岛的年代。从历史文献研究来看，这一时期估计为18世纪。除了这样的历史工作之外，南部岛屿的考古研究也没有得到很好的发展。本研究试图从民族考古学的角度来探讨这一问题，从1993年和1994年的田野调查中，我们发现威尔斯井的形态特征不仅取决于时代的发展趋势，而且还取决于下文所述的环境因素。石砌威尔斯井或碎石砌成的天然泉水的特征取决于：（1）所在地的微地形;（2）水源的相对位置;（3）水源的水量;（4）影响地下水位置的小断层、稳定的洞穴等。（5）井或泉所在地的地质条件，以及当时的技术条件，如地层的坚固或松软等。为了确定对年代学有意义的威尔斯井的构造特征，对（1）至（5）所列要素条件都相同的威尔斯井进行比较。在所调查的特征中，分布在八重山诸岛和冲绳几处的马蹄形威尔斯井可以作为一个独特的特征来识别相当古老的时代。

This research work was planned to establish a chronological framework to determine the age of diffusion of political control of the Ryukyu dynasty of the main Okinawa island to the Miyako and the Yaeyama islands, from the morphological features of religious constructions, especially the well constructed with the stone. From histrical literature studies, this age was estimated to be the 18th century. Besides such a historical work, the archaeological studies on the southern islands are not developed well. This study tries to draw ethno-archaeological perspective of the subject.From fieldwork carried out in 1993 and 1994, it became clear that the morphological features of the wells are determined not only by the tendency of the times, but also by the environmental elements described below. The feature of stone constructed wells or natural springs articulated by rubblework were decided by (1) the micro-topography of the location, (2) the relative position of the water source, (3) the quantity of the water running from the resource, (4) small faults, stalactive grottos, and so on, which influence the position of underground water streams, and (5) the technology available at that age and the quality of the ground, firm or flimsy, where the well or the spring is located.So as to identify the feature of construction of wells meaningful for the chronology, the comparison among wells of which conditions concerning the elements listed (1) to (5) are all the same. In the features investigated, the horseshoe shape wells which distribute in Kabira (the Yaeyama islands) and in several places in the main Okinawa island, can be a distinctive one to identify the rather old age.