In the capital there lived a wealthy man who one day decided to purchase some bricks to construct a wall around his home.
He was approached by a stranger, whom we shall call Mr. X, and was told, "One of the prince's residences is currently having its outer wall replaced. Why don't you go and buy the old bricks from him?"
The wealthy man was rather suspicious of this tale and replied, "The prince surely wouldn't be interested in selling his old bricks."
"I was a bit doubtful myself, but let me reassure you," Mr. X said. "I used to serve this prince and I certainly would not lie about such a matter. Why don't you send a servant along with me, and he and I will confirm the sale with the prince himself?
"Since I will have to address the prince in Manchu, your servant won't be able to understand what is said, but he'll know the deal is clinched if the prince nods his head."
The wealthy man thought this was a sensible idea and so he sent a servant, bearing a ruler with which to measure the bricks, to accompany Mr. X. The ruler was the common measure for bricks in those days, and if you bought the bricks secondhand you could often get them for half the original price.
The small party waited outside the courthouse where the prince was in attendance, and when he finally emerged, Mr. X knelt down in front of the prince's horse and spoke in Manchu.
The prince nodded and pointed in the direction of the wall in front of his residence, saying, "You are quite welcome to measure my wall. Please go ahead."
Mr. X then took the ruler, and he and the servant began to measure the wall, both length and breadth. The wall turned out to be 177 feet long. The price was calculated to be a mere 100 cash per foot. The calculations complete, Mr. X and the servant returned and gave the wealthy man the details of the transaction.