In the shipyard where my grandfather once worked, gullible apprentices were sent to a certain workshop to fetch a glass hammer. The people in that workshop would claim to have just given their last one away to somebody at the other end of the shipyard (these were huge factories). The apprentice would be sent to that next place in the hope of retrieving the glass hammer.

The apprentice would spend an entire day being sent from one person to another, each time to have his hopes dashed. Eventually one of the pranksters would send the apprentice back to the person who asked for the glass hammer in the first place. At this point, the apprentice is supposed to realise the joke and receive illumination… In practice I just think it pissed them off.

Of course a glass hammer would a truly useless thing (unless it was decorative). This prank has been played thousands of times and still continues today.