Under the strong stimulus of peasant uprising and the Aggression of Western big powers , during Jiaqing and Daoguang Dynasty,there was a practical knowledge thought movement. Yu Wan Chun concerned on the urgent social problems which needed to solve. He had done the reality research in the armament, the soldier's rations and pay, the military strength, and edited them to materials, and proposed the improvement programs by the novel form. Putting down the...