Many years ago a London theatre performed a play in which there was a great storm on the sea. In those days theatres had no machines. That is why the manager engaged several boys to make the waves of the sea. They jumped up and down under a big piece of sea-green cloth. The boys received a shilling a night for their work. They worked for several weeks. But then the manager decided to pay them less money — only sixpence a night. So the boys decided to go on strike. During a performance, when the storm began, when the wind blew and it was raining, the sea remained calm — there was not a single wave on it. The angry manager lifted once corner of the "sea" and said to the boys: "Make waves, boys, make waves !" "Do you want waves for a shilling or for sixpence?" asked a boy in a loud voice. "Oh, for a shilling," answered the manager. The boys began to jump up and down, and did it so well, that the storm looked quite real.