The licentiate Jiang of Wuyuan, whose courtesy name was Shenxiu and whose given name was Yong, could make strange machines.
He took a pig’s bladder, put yellow beans in it, blew it up tight with air and tied the neck; the beans floated exactly in the middle. It confirmed his belief in the saying that the earth is like the yolk inside an egg.
When anyone wished to become his pupil, he first made them sit and look at this bladder for seven days, without impatience or weariness, before he would teach them at all.
For the ploughing at home he used oxen of wood. When he went outside the city wall he rode a wooden donkey, which ate nothing and made no sound. People took it for sorcery. He laughed: “This is the method handed down by Marquis Wu. It is only a matter of mechanism inside. It is not sorcery.”
He made a bamboo tube with a glass cover and a key that opened it. You opened it, spoke several thousand words into the tube, and closed it again. Within a thousand li, a man who opened the tube and put his ear to it heard your voice as plainly as if you were speaking face to face; beyond a thousand li the sound gradually scattered and did not come whole.
Then one day, of a sudden, he threw himself into the water. The villagers were alarmed and pulled him out. Half-drowned, he got up and said with bitter regret: “Now I know that fate is hard to escape. My two sons are travelling abroad in Chu. Today at a quarter past the third hour past noon they are due to be drowned together in Lake Dongting. I meant to stand in for them myself. Now that you gentlemen have saved me, there will be nobody to save my two sons.”
Within half a month the bad news came. His pupil Dai Zhen told me this.
