National Geographic : 1942 Feb
Swarming Along the River Bank Like Ants, Coolies Drag Long Strands of WovenWillow Sticks tothe Dike Others carry packs of kaoliang stalks to the water's edge. Both materials rot in the water after a few years. Thennew stacks areplaced ontopoftheold, forcing the decayed mass into the mud on the river bottom. Often the entire construction is destroyed when the current scours outtherotted foundation.