When Ted Hughes finished training college, he became a teacher in a primary school. His favourite subject was geography, because he had always wanted to travel, and he studied various parts of the world so that he could feel as if he knew them a little.

　　Ted liked children, and was always ready to have a joke with them, so they learnt a lot from him while at the same time having fun.

　　One September, he was having his first lesson with a class of boys and girls, and to start with he decided to ask them some general questions, so that he could see how much they already knew. He found that this was about the average for their age, and that some of the boys and girls had obviously heard that he enjoyed a joke and were ready to have some fun with him.

　　"Where's Turkeyl?" Ted asked the first boy.

　　"Turkey, sir?" the boy answered. "You'll find it on the Christmas dinner table, sir!"

　　"Very funny!" said Ted with a smile, while the class laughed loudly. "Do you really know where it is?"

　　The boy did, in fact, know. "Part of it is in Southeast Europe and part in Asia, sir," he said.

　　"Good," said Ted. The next few pupils also had funny answers to Ted's questions, but they all knew the correct answers too.

　　Ted knew that there was one girl in the class who was very clever. She had entered the school on a scholarship that term, and it was her he turned to next.

　　"Well," he said, "now let's see if there's at least one of you who doesn't talk nonsense<注2>. What is the equator<注3>?"

　　"It's an imaginary line drawn round the earth equally distant from the North Pole and the South Pole, sir," the girl answered at once.

　　"Good," Ted said. "Very good." But it sounded to him as if the girl had learnt this by heart,<注4>so he asked her another question to see whether he was right or not.

　　"Now, do you really know what that means?" he asked. "Could you, for example, tie a knot<注5> in the equator?"

　　The class laughed, but she answered, "Yes, sir."

　　"Oh, really?" Ted said with a smile.

　　"Yes, sir," the girl said. "As the equator's an imaginary line, you could tie an imaginary knot in it."

　　This time Ted joined happily in the class's loud laughter.