notion had fired a man’s brain, he could not be convinced that perpetual motion was impossible. American inventors simply ignored the discouraging statements of scientists. Their heyday, which stretched from about 1825 to 1910, was a period of optimism, when many long-sought goals were attained. Steam performed new wonders, sewing machines made stitches, carriages ran without horses, and airplanes flew like birds. These marvels achieved, what layman would doubt that water could eventually be made to run uphill by itself, or that a wheel could be designed to be constantly heavier on one side than on the other and so spin forever? Newspapers were believers, too; the Philadelphia Gazette reported in 1829:
We were much gratified yesterday with the result of an examination of a self-moving machine, which may be seen at Bowlsby’s Merchants’ Hotel, in Slater Street, and which the inventor calls perpetual motion. We have no doubt of it being nearer a perpetual self-moving principle than any invention which has preceded it, and as near as any we shall ever see. The great merit, aside from its practical uses, is its simplicity, and the certainty and readiness with which you perceive that it covers no trick or deception.

Anyone, including editors, who believed in a particular device seems to have clung to his belief with the tenacity of the inventor himself. A shining example of such loyalty appeared in the New York Journal of Commerce, which in 1854 described a machine invented by one J. G. Hendrickson:
The model was in our office yesterday, and attached to some clockwork, which it turned without once stopping to breathe. We see no reason why it should not go until worn outl After a careful examination, we can safely say, in all seriousness, that the propelling power is self-contained and self-adjusting, and gives sufficient force to carry ordinary clockwork, and all without any winding up or replenishing.

In 1868, the Journal published a follow-up:
About fourteen years ago we published the first description of a machine invented by Mr. James G. Hendrickson of Freehold, N.J. … [and] we saw no reason why it would not go until it was worn out. The inventor was an old man, who had spent his whole life in pursuit of the object he had now attained. He was invited to be present at various fairs and exhibitions of new inventions, and wherever he went, his machine formed one of the chief attractions. The professors were all against him. Accordingly, Mr. H. was seized at Keyport, N.J., for practising “jugglery” under the “Act for Suppressing Vice and Immorality.” To expose the supposed trick, an axe was brought, and the cylinder splintered into fragments. Alasl There was no concealed spring, and the machine had “gone of itself.” He made a new machine. His model once more completed, was constructed of brass, hollow throughout. The moment the blocks were taken out,

the wheels started off “like a thing of life"; and, during ten months, it never once stopped. The inventor had perfected two new machines, and made a very comfortable livelihood exhibiting them, prosecuting his efforts meanwhile to secure his patent. Age crept upon him, however, before this point was reached; and last Saturday afternoon he breathed his last at Freehold. The night after his death his shop was broken open, and both models stolen. (!)

Here was a field made to order for fakers, and all kinds of humbugs were built to fleece a gullible public. Perhaps the most notable of these devices, and certainly the most fascinating, was the Redheffer perpetual-motion machine, described many years later by Daniel Hering. It was twice exposed, once by a pair of trained eyes, and again by a pair of sensitive and famous ears.

Charles Redheffer (or Redhoeffer) first appeared with his marvelous machine in Philadelphia in 1812. He installed it in a home on the city’s outskirts, charging admission to watch it run, seemingly as long as he wished. Soon Philadelphia became embroiled in an argument as to whether this really was the long-sought perpetual motion. Huge wagers were made as to its authenticity. Charles Gobert, a civil engineer (perhaps in the pay of Redheffer), placed the following announcement in the Philadelphia Gazette , July 12, 1813:
I hereby offer, on demand, any bet or bets from 6,000 to 100,000 dollars, to the end of proving, in a few days, both by mathematical data and three several experiments, to the satisfaction of enlightened judges, chosen by my very opponents out of the most respectable gentlemen of this city, or of New York, that Mr. Redheffer’s discovery is genuine, and that it is incontestibly a perpetual self-moving principle … This is to be valid until the 15th inst., at sunsetting.

At this juncture, the Pennsylvania legislature took an interest and appointed a commission of eminent engineers to decide upon the validity of Redheffer’s machine, probably the only time in American history that a perpetual-motion machine was so dignified.

On the appointed day the commission appeared at the house and found it locked. No one answered the bell. However, through a barred window the commissioners could see the machine working in lonely magnificence. It consisted of weighted cars continually ascending and descending inclined planes. A shaft was geared to it, apparently to perform useful work.

One of the commissioners, Nathan Sellers, had brought along his son, Coleman, reputed to be a mechanical genius. Peering through the window, young Sellers noticed something which escaped the attention of the adults. At the point where the shaft was geared to the mechanism, the cogged wheels were a bit worn, and they were worn on the wrong side of the cogs . Only one conclusion was possible: instead of powering the shaft, the mechanism was powered

by the shaft.

When the lad told his father what he had seen, the senior Sellers hired a skilled mechanic to make a machine identical to Redheffer’s, except that it was driven by a spring concealed in an ornamental post (a device that was to become a favorite of later fakers). Redheffer, brought to see the machine, was thunderstruck. He believed in it instantly. Here, to his mind, was real perpetual motion. Young Sellers had done what he had only claimed to do. He tried to buy out the lad, offering him a handsome share of the profits that could be made from this, the true perpetual motion.

Later in 1813, a machine identical to Redheffer’s, and possibly exhibited by him, appeared in New York, and Robert Fulton, who had launched the Clermont six years earlier, was induced by some of his friends to visit the exhibit. Shortly after he entered, Fulton exclaimed, “Why, this is a crank motion.” His sensitive ears had detected the uneven sound, induced by unequal velocity, which is typical of the motion imparted by a crank, rather than of the rotary motion implied by the machine. Fulton declared the machine a fraud and denounced the exhibitor to his face as an impostor. When the spectators became embroiled in the argument, Fulton declared that he would expose the machine or pay for any damage he did to it. Thereupon he knocked away a few thin pieces of wood which fastened the contrivance to the wall. Inside, a loop of catgut was moving at a fairly steady pace. Speculating that the gut ran up through the wall and along the ceiling above, Fulton started exploring the second floor of the building. Finally, according to his biographer, C. D. Golden, he threw open a door at the back of the house, where he discovered the true motive power—a poor old wretch with an immense beard who appeared to have suffered long imprisonment. He was unconscious of what had happened below and was seated on a stool gnawing a slice of bread which he held in one hand while turning a crank with the other. The irate mob demolished the machine, and the promoter vanished.

The infamous Keely Motor of 1874 was another perpetual-motion fraud, as well-known in its day as the equally spurious Cardiff Giant. John Worrell Keely was a good mechanic, but an even better talker; when the smooth words flowed, nearly everyone within earshot believed. In a typical demonstration, Keely would start his machine, which seemed to run on water, either by striking a tuning fork or playing a tune on a harmonica, and it would run until he stopped it. A master of scientific double talk, Keely called his mechanism successively a “vibratory generator,” a “hydro-pneumaticpulsating-vacu-engine,” and an “energy liberator.”

For twenty-five years the machine ran, and the smooth words flowed. Always Keely needed “just a little more

money” to perfect it. He even claimed that it could propel a large ocean liner from New York to Liverpool and back on a gallon of ordinary water. His technical terms became even more mystifying and alluring, and he talked of “molecular vibration,” “sympathetic equilibrium,” and “oscillation of the atom.”

When the fraud was at last discovered, it turned out that water indeed played its role. The house in which the machine had been demonstrated had been remodeled and contained a high-pressure hydraulic system connected almost invisibly to the machine.

As late as March, 1899, McClure’s Magazine carried a startling article on a machine invented by one Charles E. Tripler of New York. If the machine worked (and the writer of the article seemed to underwrite its authenticity), it would make perpetual motion not only possible but almost inevitable. The writer was Ray Stannard Baker, a man who was to become something of a figure in American history—eminent author, historian, government agent, and friend and confidant of Woodrow Wilson. At the invitation of Mr. Baker, two scientists visited Tripler’s laboratory for a demonstration. Though an appointment had been made, the time proved “not to be convenient” for Tripler, and the scientists never examined the machinery. There never was, indeed there never is, a convenient examination for such devices. This is almost another law of physics.

Again in 1902 a civil engineer presented a paper that implied the possibility of perpetual motion at a meeting of the American Association for the Advancement of Science.

The second law of thermodynamics is fallacious [argued the inventor]. The effect of an operation can always be reversed, and when produced by an operation which is made irreversible by the unrestrained or unbalanced action of some particular element or elements, can be reversed by another irreversible operation made irreversible by the unrestrained action of another element or elements having an opposing action to the first mentioned element or elements.

I wish to contribute the above statement to Physical Science.

It is quite a contribution.

But one kind of “perpetual motion” is, after all, quite possible. Let inventors take heart; or better, read a book by a mathematician named Mudie, published as far back as 1836, and called Popular Mathematics:
It is not difficult to calculate (upon mathematical principles) that if we could give any piece of matter a motion round the earth at the rate of about five miles a second, or 1,800 miles an hour, and keep up the motion at this rate, we should overcome the gravitation of that piece of matter. This is what may be regarded as the possible case of perpetual motion.

The multiplication is a little off, but who, conscious of sputniks circling the earth endlessly, can deny that this was right?

Buried in every perpetual-motion scheme is

a flaw in the inventor’s reasoning. Frequently the basic idea is so clever that even a trained observer has difficulty in peeling away the layers of brilliant logic and unearthing that fatal error. Nor is it usually the simple argument that there is “too much friction.” The author’s simplified diagrams show some of the classic perpetual-motion schemes which Americans have invented and reinvented scores of times. In each of the schemes a law of nature, a basic principle which the inventor has overlooked, is going to stop the device. With each machine, the inventor’s claims are given. What is wrong? The correct answers are on page 85.

Answers to WHY WON’T THEY WORK?