text: charles redheffer charles redheffer was an american inventor who claimed to have invented a perpetual motion machine . first appearing in philadelphia , redheffer exhibited his machine to the public , charging high prices for viewing . when he applied to the government for more money , a group of inspectors were sent to examine the machine . it was discovered the machine was actually powered by a device redheffer claimed was powered by the machine . redheffer moved to new york city and set up a similar scam after rebuilding his machine . however , an engineer detected that it was a fake when he visited an exhibition by listening to its unsteady motions . he discovered that the machine was operated by a man using a crank in a room on the floor above . redheffer returned to philadelphia . he later claimed to have created another machine , but refused to demonstrate it to anyone . he managed to get a patent for his machine in 1820 , but after this his fate is unknown . personal life little has been recorded about redheffer 's life , other than his connection to the hoax . according to one source , he was from germantown in philadelphia , but most sources simply state that he appeared in philadelphia with his machine . redheffer disappeared from public view after the discovery of the fraud , and his fate is unknown . appearance in philadelphia charles redheffer and his machine became well known in philadelphia in 1812 . redheffer claimed he had invented a perpetual motion machine and exhibited it in a house near the schuylkill river in the outskirts of the city . he charged an admission fee of $ 5 ( some sources claim $ 1 ) for men to view it ; depending on the source , women were admitted free or at a charge of $ 1 . the machine caused a sensation , and redheffer lobbied for funds to build a larger version . on january 21 , 1813 , eight city commissioners visited redheffer to inspect the machine . they had to do so through a barred window , as redheffer was concerned anyone going near the machine might damage it . one of the inspectors , nathan sellers , was accompanied by his son coleman , who noticed something odd about the gears . the machine itself was said to be powering a separate device through a series of gears and weights . coleman noticed that the cogs were worn on the wrong side and suggested that the device was in fact powering the machine . the elder sellers was convinced the machine was 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 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 would have powered 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 ) for a device listed as " machinery for the purpose of gaining power " . ( unfortunately , all patents up to 1836 were lost in the 1836 u.s. patent office fire . if recovered , it would be x - patent . )