Fable of Qiantang geomantic omen

In the old days, there was a two-part allegorical saying in Hangzhou called "Building a bridge on Qiantang River-impossible". That's because the Qiantang River is 3 kilometers wide, the geological structure is complex, the river tide is turbulent, and it is difficult to build a bridge. It was a popular two-part allegorical saying at that time. This is a two-part allegorical saying circulated in Hangzhou by Mao Yisheng, a Chinese bridge expert, before the Qiantang River Bridge was built. With the completion of the bridge, this two-part allegorical saying has already been rewritten by Mao Yisheng.