Two Corkmen were escaping from a well-protected jail at night. All they had
with them was a flashlamp, so when they reached the forty-foot wall surrounding
the jail one Corkman said to the other:
'I'll shine the flashlamp up to the top of the wall and you climb up along the
'Hold on', said the second Corkman, 'how do I know that you won't switch off the
lamp when I am halfway up?'