Abstract
On the ancient city wall of China, the water gate used to been built. Probably before the Tang Dynasty, it always took the shape of hole in order to drain and prevent others from entering city. From the Song Dynasty on, for the sake of navigation, the majority of water gates became the sluice gate that could go up and down.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have