- 日本建築学会計画系論文集 (ISSN:13404210)
- vol.83, no.754, pp.2409-2417, 2018 (Released:2018-12-30)
It is known that French Jesuit Michel Benoit designed fountains and hydraulic machinery called "Shuifa" for the European palaces called "Xiyanglou" in Yuanmingyuan. Though Jesuit correspondence tells that the construction of Xiyanglou was initiated by the Qianlong Emperor after seeing pictures of European fountains, there are only a few studies on Benoit's role or his hydraulic machinery, and hardly any previous studies pay attention to the practical problems of their construction. Thus the paper aims to focus on the construction phase of the hydraulic machinery, to reveal the characteristics of the actural machinery in terms of its technology applied by Qing craftsmen, and examines the novelty and feasibility of the machines from their perspective. There are several letters by French Jesuits reporting that Benoit designed the fountains and hydraulic machinery for the European palaces. One of them describes how Benoit made "la célèbre machine du val de Saint-Pierre", which is thought to be "une Machine exécutée au Val Saint Pierre", described in Bernard Forest de Belidor's Architecture Hydraulique. Xushuilou and Haiyantang are known to have contained hydraulic machinery to raise the water and associated water reservoirs. The machine of Val Saint Pierre can be divided into two part: a crank machine using pin face wheel, lantern pinion, elliptical cranks and pendulums, and a reciprocating pump using piston or plunger. The former are mostly made of wood, and the later are of cooper and cast iron, with lead water pipes attached to its body. They have not been used in previous studies, but there are two architectural documents from the Qing dynasty that likely describe the crank machine and pumps of the hydraulic machinery in Xushuilou. Through the comparative analysis aided by Table 1 using the above-mentioned documents and Belidor's book, it can be observed that Qing craftsmen made some changes to the original machine in Belidor's book — for example they used bitumen, cloth and rope, and tin pipes to substitute for lead pipes. Another important aspect is the estimation of labor: the documents tell that one crank machine needs 100 man-days to finish installing, which is quite a lot compered to other water-related machines described in the same documents. Through the analysis of events relevant to European hydraulic knowledge transfer during the 17th and 18th century in the court aided by Table2, and supplemented by Table3 which suggests interpretations of the word Shuifa and related terms, it could be said that the book Taixishuifa published in 1612 was the origin of the word "Shuifa", which first meant hydraulic machinery and later both hydraulic machinery and fountains. It is known that the Yongzheng emperor has once ordered missionaries to make a fountain which was not realized. The author also found reports of a missionary's execution of portable fountains in 1717, and descriptions of Qianglong's order to execute Shuifa in 1771. The most important thing to highlight here is that several experiences of pump making during the reign of Yongzheng could have prepared the technical basis for the manufacture of copper pumps. Yet the substitution of the machines of Xushuilou and Haiyantang in 1763, and the demolition of them in 1795 were the crucial moments to explain that the maintenance and repairs of the crank machines were not easy for Qing craftsmen. It has been demonstrated that Belidor's Architecture Hydraulique played an important role when Benoit designed the hydraulic machinery placed in the Xushuilou building. However in the construction phase, the Qing craftsmen's experiences of various pumps might have played a more important role. Therefore, it could be concluded that the novelty of Benoit's machinery was limited.