In the days before the advent of the mobile phone, and even when fixed lines were scarce, an engineer's wife was expecting, and the baby was due any day....
The engineer was very confident that it would be a boy, and was eagerly looking forward to the delivery day....
As fate would have it, he was transferred to another city at the time the baby was due, and had to leave immediately to take up his new post....
Before going, he asked his father-in-law to send a telegram confirming the birth of his son....
But in order to avoid giving a party to his office colleagues, he asks his father -in-law to write
"The Clock Has Arrived,"_ and he will understand that the son is born....
The D-day arrived. His wife delivered a cute little baby girl....
Now the engineer's father-in-law didn't know what to do.
If he writes _"The Clock Has Arrived,"_ the son-in-law will think he has a son....
If he writes _"The Clock Has Not Arrived,"_ the son-in-law will get worried that something serious has happened....
Being a very intelligent person, he finds a solution, and sends the telegram....
Son in law received the telegram, opened it eagerly & read....
"The Clock Has Arrived, But The Pendulum Is Missing."_