A potato farmer was sent to prison just at the time when he should have been digging the ground for planting the new crop of potatoes. He knew that his wife would not be strong enough to do the digging by herself, but that she could manage to do the planting; and he also knew that he did not have any friends or neighbours who would be willing to do the digging for him. So he wrote a letter to his wife which said, 'Please do not dig the potato field. I hid the money and the gun there.'
Ten days later he got a letter from his wife. It said, 'I think somebody is reading your letters before they go out of the prison. Some policemen arrived here two days ago and dug up the whole potato field. What shall I do now?'
The prisoner wrote back at once, 'Plant the potatoes, of course.'