There was an expectant father who had spent quite some time waiting for the offspring to arrive – at his in-laws’ place.

As his leave balance had gone into the red, he tells his father-in-law,

“When my son comes do not call up my office and say that I have become a father of a boy because I’ll have to shell out a lot for parties. Just leave me a message that the clock has arrived. This will be our code for the arrival of the baby.”

The offspring does finally arrive one day but it’s a daughter.

The father-in-law now thinks to himself,

“If I tell him that the clock has not arrived he’ll misunderstand and think that something has happened to the baby and come rushing over.”

So the father-in-law left the following message:

“The clock has arrived but the pendulum is missing.”