Two Parisian model train enthusiasts were engrossed operating their scale equipment in Montemarte. As the little trains went running about the tracks, cleverly controlled by the operators at the control panel, one of the engines kept falling off the rails each time it went through a certain siding switch.
One of the hobbyists, exasperated at the constant derailment, asked the other if he had an explanation. His partner examined the faulty switch and suddenly came upon the reason. "Ah, Pierre," he cried, "I see now the reason why the train she keep derailing. It is too loose, le track."