Stonefish introduction: Among the Baiheliang inscriptions, there is a stonefish marked as the earliest dry water inscription. Its eyes are exactly the zero water level of the middle and upper reaches of the Yangtze River, which is higher than the first stonefish established on the Yangtze River in 1865. Water gauge - The water level observation record of Wuhan Jianghan Pass water gauge dates back more than 1,100 years.