A Preliminary Study on the Spherical Bombs (Huolei) of the Southern Song Dynasty, Unearthed in Chongqing1

The military situation of the thirteenth century required that the Song and the Mongols construct a great number of defensive works, relying on the mountains or facing the rivers, in the mountainous Sichuan Province and Chongqing. In recent years, a special kind of explosive firearms, huolei 火雷 (bombs), was unearthed in the large-scale excavations of the site of Diaoyu Fortress 钓鱼城 in Hechuan District 合川 and the Baidicheng 白帝城 in Fengjie County 奉节 , both of which were defensive works constructed in this mountainous area during the Southern Song dynasty. In addition, the ruins of kilns and the clay molds that were relevant to the casting of iron huolei have been discovered at the site of Baidicheng, indicating that these huolei might have been produced locally. The Southern Song iron huolei unearthed in Chongqing are the most direct evidence of the evolvement of gunpowder and firearms, and are of great significance to the history of science and technology, in particular the history of military technology.