美国国会图书馆藏《松江府海塘图》的年代判定及其价值

The Age's Estimation and Value of the Map of Seawall in Songjiang Prefecture Stored Away in the Congress Library

在前辈学人研究的基础上,根据美国国会图书馆所藏《松江府海塘图》和乾隆《太镇海塘纪略》中所附地图的比对,可知两图所载各县海塘长度的差异主要是由各自丈量尺度的不同造成。加之镇洋北岸海塘长度以及两图所示地域范围的差别,可以判定美国国会图书馆所藏的《松江府海塘图》绘制于乾隆十七年,该图更名为《乾隆松太海塘图》较为合适。《乾隆松太海塘图》是清代江南海塘的通塘体系形成之前最完整的一幅海塘图,图中所画内容反映了官方绘制江南海塘图"兵农并重"的特殊要求,是同类海塘图中的珍品。

On the basis of the former research, the author compared the Map of Seawall in Songjiang Prefecture packed away in the Congress Library with the map as addenda of a book -- Summary Track Record of Haitang in Taicang and Zhenyang Prefectures in Qianlong Period, and found that the＇length＇s difference of seawall in corresponding counties was brought on by the varied standards of scales. This conclusion meant that the length of seawall in two maps was the same and the two maps might be painted at time that not long from one to the other. On the other hand, the distinction of the two maps on the area of these prefectures and the length of seawall at the north bank of Zhenyang helped the author to make a further estimation. At last, the author alleged that the Map of Seawall in Songjiang Prefecture was painted at the seventeenth year of Qianlong period. He also suggested that the Map of Seawall in Songjiang and Taicang Prefectures in Qianlong Period is a more appropriate name for it. The Map of Seawall in Songjiang Prefecture is the most integral map about Jiangnan Seawall in Qing period before the accomplishment of the Perfect Seawall System. The content of the map implied some official requirement for the building of Seawall, such as the same importance of military affairs and the farming. This map is a titbit.