《徐霞客游记·楚游日记三》
水面的宽处超过前面那崖壁上的，但水分成两级折下山峡间，先看见上面的一级，然后见到下面的那级，所以觉得它不如前面崖壁上的那样飞流直下。
前即宁水桥，问水从何处，始知其南由唐夫沙河而下衡州草桥。
The width of the water surface exceeds that of the cliff wall in front, but the water is divided into two levels and flows down the gorge. First, you can see the first level above, and then the second level below. Therefore, you feel that it is not as straight as the one on the cliff wall in front.