Quotation from: The Little Lady of the Big House

Written by: Jack London

But the opportunity had passed. On a down grade, the engine picked up
the train rapidly. Facing the moving cars, with empty air at his back
and the depth beneath, Tim tried to drop on hands and knees. But the
first twist of his shoulders brought him in contact with the car and
nearly out-balanced him. By a miracle he recovered equilibrium. But he
stood upright. The train was moving faster and faster. It was
impossible to get down.