In 1812 a Philadelphia man, Charles Redheffer, claimed to have invented a perpetual motion machine that required no source of energy to run. He built a working model of the machine and applied for funds from the city government to build a larger version. But when inspectors from the city examined it, they realized that Redheffer had simply hidden the power source. To expose Redheffer, they commissioned a local engineer to build a similar machine, and when they showed this to Redheffer he fled the city. (This replica is still owned by the Franklin Institute in Philadelphia.)

A year later, Redheffer attempted the same scam in New York City. This time he was exposed by the engineer Robert Fulton who is said to have removed some boards from a wall neighboring the machine, exposing the source of the machine's power: an old bearded man sitting and eating a crust of bread with one hand, while he turned a hand-crank with the other.