The T’ang dynasty lasted from A.D. 618 to 907. And during this important period in Chinese history, block printing was invented, Buddhism became very strong, and certain areas of the surrounding territory were conquered. The rulers were very rich, especially during the early years of the dynasty, when the T’ang emperor, T’ai-tsung, sat on the throne.
The time came when the emperor wished to find a worthy husband for his daughter, Wen-ch’en, who was a very beautiful, intelligent, and elegant young woman. When the emperor’s wishes became known to the ruler of a kingdom adjoining the T’ang empire, he sent his most trusted official, Prime Minister Lu, to ask on his behalf for Wen-ch’en’s hand in marriage. When the prime minister arrived, he found the representatives of four other rulers there ahead of him.
After some thought, the emperor decided to pose five puzzles for the visiting emissaries to solve. “The ruler whose official shows the greatest wisdom will marry my daughter,” he declared. “After all, he must be very wise if he has chosen such a clever official to serve him. Therefore, he should make a suitable husband for Wen-ch’en.”
The emperor assembled the five emissaries, and ordered one of his courtiers to bring in a length of thread and a large ivory bead, with a hole on either side of it. “Here is the first of five puzzles I shall ask you to solve,” Emperor T’ai-tsung explained. “These holes are connected by a zigzag path. Whoever can thread the bead will solve the first puzzle.”
Each emissary took a turn twisting the thread and trying to string the bead. The first four coaxed it gently, then they tried to force it, and at last they gave up. When Prime Minister Lu’s turn came, he lifted up a tiny ant, looped the thread around its body and placed it at one of the openings in the bead. He blew as hard as he could on the ant and it sped swiftly through the zigzag passageway to the other end.
Emperor T’ai-tsung was impressed. “You are a very clever man. Now, if all of you will follow me, we shall see who can find the answer to the second puzzle.”
Out in the courtyard they found a large pile of cut logs. The emperor said, “There are about a hundred logs here. Can one of you tell me which end of each grew closest to the tree’s roots?”
Four of the emissaries frowned and thought hard, but they could not guess the answer.
Prime Minister Lu asked respectfully, “Your Imperial Highness, am I permitted to have these logs placed in the pond of your courtyard?”
“I have no objection,” the emperor graciously replied.
When the logs had been put into the water, one end of each log sank slightly below the surface while the other bobbed on top of the water.
Prime Minister Lu declared, “The ends beneath the surface are heavier and denser because they are nearer the tree roots and the lighter ends are closer to the tops of the trees.”
“You have solved the first two puzzles very cleverly indeed,” the emperor complimented, “but I wonder whether you will figure out the third.” He smiled and led the five men out to the stables. There he pointed out one hundred mares and one hundred foals. “Your next puzzle requires you to pair each young horse with its mother.”
The five officials walked around looking perplexed at the mares and foals.
It cannot be the size or color, thought Prime Minister Lu. The next day when the emperor asked the officials to match the mares and foals, each of the first four replied that the task was impossible.
Prime Minister Lu confidently said, “Let all the mares be taken from the stables and the foals kept inside. The foals may eat as much hay as they like all day long but they may not be given a single drop of water to drink.”
The next day Prime Minster Lu asked that the foals be let out of the stables. Each foal ran to its mother to drink.
T’ai-tsung was delighted at Prime Minister Lu’s ingenuity. He praised him highly and then told the five that there would be no more puzzles to solve that day. Four of the officials spent the day resting, but Prime Minister Lu wandered in the courtyard, speaking kindly to the courtiers and servants he met and inquiring about the life of the court.
That night as all the officials lay sleeping in the guesthouse, they were suddenly awakened by a tremendous noise of gongs and drums. A courtier suddenly appeared and bowed low. “You are summoned to the presence of his Imperial Highness,” he told them. Then he vanished.
Prime Minister Lu was thoughtful, It is strange indeed that we must find our way to the emperor ourselves. I wonder if this is another puzzle. It will be quite easy to reach the imperial quarters by following the noise of the gongs and drums, but it will be quite difficult to return here in the darkness. Trailing behind the other four officials, he carefully made a small mark at every corner so that he could find his way back.
As soon as the emperor had greeted the five emissaries, he dismissed them with instructions to return at once to their guest quarters.
“The first one to find his way back to the guesthouse will have solved the fourth puzzle,” he announced.
The first four officials stumbled and fumbled in the dark and soon were hopelessly lost in the confusion of the many passages. Treading softly, Prime Minister Lu felt for the marks he had notched at each turn and returned quickly to the guesthouse.
“Prime Minister Lu has won again!” the emperor declared. “But there is one final puzzle to solve tomorrow. It is the most important of all.”
When the five officials gathered the next day, they were faced with a long line of beautiful young girls in silken robes. T’ai-tsung announced, “My daughter, Wen-ch’en, is one of these girls. Which one is she?”
The first four emissaries, eager to make up for failing to solve the other puzzles, quickly chose one of the girls and said, “Your Imperial Highness, this is your daughter.”
But Prime Minister Lu had listened to the talk of the courtiers and the servants while the other officials had spent their time resting. He remembered that one courtier had spoken of Wen-ch’en’s long, glossy black hair while another talked of her pearl white skin. Yet someone else admired her graceful figure and the proud way she held her head high. But of most importance, Wen-ch’en’s little maid servant had told the prime minister that her mistress had a tiny mole on her left wrist so he looked for that.
Prime Minister Lu selected one of the girls and said, “Your Imperial Highness, this girl, most beautiful of all, is your daughter.”
“You have performed the task given you by your ruler perfectly,” the emperor said. “This is indeed my daughter, Wen-ch’en. I give her in marriage to your ruler. He is an extremely wise man to have placed you in his service.”