据说这一习俗可以追溯到18世纪末期时的乾隆下江南。
This practice is said to date back to the late 18th century , when Emperor Qianlong went on a fact-finding mission to the south of China .
所以才有了乾隆皇帝下江南,有四次都是住在这里的故事。
That 's why during his southern inspection tours , the emperor stayed here on four occasions .