PERPETUAL MOTION MACHINES 201
ing to legend, his maid later exposed his machine as a fraud.) Even the
great renaissance painter and scientist Leonardo da Vinci became interested in perpetual motion machines. Although he denounced them
in public, comparing them to the fruitless search for the philosopher's
stone, in private he made ingenious sketches in his notebooks of selfpropelling, perpetual motion machines, including a centrifugal pump
and a chimney jack used to turn a roasting skewer over a fire.
By 1775 so many designs were being proposed that the Royal Academy of Science in Paris stated that it would "no longer accept or deal
with proposals concerning perpetual motion."
Arthur Ord-Hume, a historian of these perpetual motion machines, has written about the tireless dedication of these inventors,
working against incredible odds, comparing them to the ancient alchemists. But, he noted, "Even the alchemist... knew when he was
beaten."
HOAXES AND FRAUDS
The incentive to produce a perpetual motion machine was so great
that hoaxes became commonplace. In 1813 Charles Redheffer exhibited a machine in New York City that amazed audiences, producing
unlimited energy for free. (But when Robert Fulton examined the machine carefully, he found a hidden cat-gut belt driving the machine.
This cable was in turn connected to a man secretly turning a crank in
the attic.)
Scientists and engineers, too, got swept up in the enthusiasm for
perpetual motion machines. In 1870 the editors of Scientific American
were fooled by a machine built by E. P. Willis. The magazine ran a
story with the sensational title "Greatest Discovery Ever Yet Made."
Only later did investigators discover that there was a hidden source of
energy for Willis's perpetual motion machine.
In 1872 John Ernst Worrell Kelly perpetrated the most sensational
and lucrative scam of his day, swindling investors of nearly $5 million, a
princely sum back in the late nineteenth century. His perpetual motion
ing to legend, his maid later exposed his machine as a fraud.) Even the
great renaissance painter and scientist Leonardo da Vinci became interested in perpetual motion machines. Although he denounced them
in public, comparing them to the fruitless search for the philosopher's
stone, in private he made ingenious sketches in his notebooks of selfpropelling, perpetual motion machines, including a centrifugal pump
and a chimney jack used to turn a roasting skewer over a fire.
By 1775 so many designs were being proposed that the Royal Academy of Science in Paris stated that it would "no longer accept or deal
with proposals concerning perpetual motion."
Arthur Ord-Hume, a historian of these perpetual motion machines, has written about the tireless dedication of these inventors,
working against incredible odds, comparing them to the ancient alchemists. But, he noted, "Even the alchemist... knew when he was
beaten."
HOAXES AND FRAUDS
The incentive to produce a perpetual motion machine was so great
that hoaxes became commonplace. In 1813 Charles Redheffer exhibited a machine in New York City that amazed audiences, producing
unlimited energy for free. (But when Robert Fulton examined the machine carefully, he found a hidden cat-gut belt driving the machine.
This cable was in turn connected to a man secretly turning a crank in
the attic.)
Scientists and engineers, too, got swept up in the enthusiasm for
perpetual motion machines. In 1870 the editors of Scientific American
were fooled by a machine built by E. P. Willis. The magazine ran a
story with the sensational title "Greatest Discovery Ever Yet Made."
Only later did investigators discover that there was a hidden source of
energy for Willis's perpetual motion machine.
In 1872 John Ernst Worrell Kelly perpetrated the most sensational
and lucrative scam of his day, swindling investors of nearly $5 million, a
princely sum back in the late nineteenth century. His perpetual motion