a hoax. To validate his suspicions, he hired local engineer Isaiah Lukens to build a similar machine, using a hidden clockwork motor as a power source. They then arranged a demonstration of the machine to Redheffer, who was immediately convinced and offered to buy it. Meanwhile, Redheffer's machine appeared in the Philadelphia Gazette. Civil engineer Charles Gobort offered to bet sums of money ranging from $6,000 to $10,000 that the machine was genuine, and that Redheffer had discovered perpetual motion. Move to New York City His ruse revealed, Redheffer immediately departed for New York City where he was still unknown. He changed his machine somewhat so that it could not be detected as easily, and he exhibited it as he had done in Philadelphia. When mechanical engineer Robert Fulton went to see the machine, he noticed that the machine was unsteady as if someone were driving it manually and irregularly with a crank. Fulton also detected that the sound was uneven, uncharacteristic of a machine's motions. He announced the machine was a fraud, and challenged Redheffer exclaiming he would expose the secret power source, otherwise he would pay for all the damage he would cause. Redheffer agreed, so Fulton removed some boards from the wall alongside the machine and exposed a catgut cord that led to the upper floor. Upstairs he found an old man who was turning a hand-crank with one hand and eating bread with the other. Spectators realized they had been duped and destroyed the machine; Redheffer fled the city. Later appearances Redheffer appears to have constructed another machine in 1816, which he stated his intention to demonstrate to a group of men including the mayor and chief justice of Philadelphia. However, despite several meetings, Redheffer refused to demonstrate the machine to them. On July 11, 1820, the U.S. Patent Office granted a patent to Charles Redheffer (or Charles Redheiffer) for a device listed as "machinery for the purpose of gaining power". (All patents up to 1836 were lost in the 1836 U.S. Patent Office fire. If recovered, it would be X-Patent X3,215.) Notes References Hoaxes in science Hoaxes in the United States Perpetual motion 19th-century hoaxes Year of birth unknown Place of birth unknown Year of death unknown Place of death unknown