Read this great piece from
Charlie and the Great Glass Elevator,Alfred A. Knopf, Inc. 1972, p. 36
"This is the Gilligrass Patent Fly-Trap!" They all crowded
round to look. [see the figure]
"The fly climbs up the ladder on the left," said the President.
"He walks along the plank. He stops. He sniffs. He smells something good. He peers over the edge and sees the sugar lump. 'Ah-ha!' he cries. 'Sugar!' He is just about to climb down the string to reach it when he sees the basin of water below. 'Ho-ho!' he says. 'It's a trap!'
They want me to fall in!' So he walks on, thinking what a clever fly he is. But as you see,
I have left out one of the rungs in the ladder he goes down by, so he falls and breaks his neck."
"Tremendous, Mr. President!" they all exclaimed. "Fantastic. A stroke of genius!"...