There was a little conservative father who had spent quite some time waiting for his first child to be born at his in-laws place.
He was absolutely positive that his wife was going to give birth to a boy.
He told his father-in-law, "When my son comes, do not call up office and say that I have become a father of a boy. Then I'll have to give parties to all the colleagues. Just leave a message that that ' The clock has arrived'. This will be our code for the birth of my son."
The child is born one day, but it's a daughter. The father-in-law now thinks, "If I tell him that the
clock has not arrived, he'll misunderstand that some thing has happened to the baby and come rushing over."
So he sends the message, "The clock has arrived, but the pendulum is missing."