Henry Ernest Dudeney/Puzzles and Curious Problems/58 - When did the Dancing Begin

by : $58$

 * When did the Dancing Begin?
 * "The guests at that ball the other night," said Dora at the breakfast-table,
 * "thought that the clock had stopped,
 * because the hands appeared in exactly the same position as when the dancing began.
 * But it was found that they had really only changed places.
 * As you know, the dancing commenced between ten and eleven o'clock.
 * What was the exact time of the start?"