Perpetual Motion Machines Proposed in Europe (See Bot Conceived by the Contemporary Dutch Artist Maurits C

Home , Perpetual motion

PERPETUAL WATERFALL, one of many "impossible objects" the first perpetual motion machines proposed in Europe (see bot conceived by the contemporary Dutch artist Maurits C. Escher, tom illustration on page 1 I"6). Their designers did not realize that, seems to drive a mill wheel endlessly. Mills that produced enough because of the energy losses due to friction, no mill is capable of power to recirculate the water needed to drive them were among pumping all its water supply back to the uphill starting position.

114

400 r Over the past years nun1erous inventors have proposed n1a velous ways of getting s Olnething for nothing. All these proposals have first foundered on either the or the second la\v of thern10dynamics

hy Stanley W. Angrist

he interwoven tapestry of history Villagers and townspeople who had As can be judged by Wilkins' leading Tsometimes displays odd relation no access to running water naturally role in the scientific community, specula ships. Who would think, for ex sought alternative sources of power. One tion on perpetual motion machines was ample, that two medical men would be result was the windmill, a thoroughly not yet considered a crackpot activity. leading figures in the history of efforts to practical invention. A less practical re Robert Boyle recounted in detail his ex make a perpetual motion machine? One sult was a series of proposals for closed amination of a Ruid, compounded of bi of them, the 17th-century English physi cycle water mills such as the one that tuminous oils and similar ingredients, cian Robert Fludd, is usually mentioned Fludd put forward in 1618. The proposal that an engineer of his acquaintance had as one of the first to propose a perpetual must have seemed sensible enough at prepared as a charge for fire bombs. The motion machine to do useful work. The the time. If the water that turns a mill engineer had mixed the ingredients over other, the 19th-century German physi wheel could be collected from the race a fire and was surprised to find that days cian Julius Robert Mayer, was among at the foot of the wheel and somehow after the pot had been left to cool the those who established as a law of nature put back into the reservoir above the Ruid in it still swirled about. Keeping the conservation of energy, which dooms wheel, the need for a source of running the pot in his laboratory for a time, Boyle proposals such as Fludd's. water would disappear. Centuries of ex observed that the oilier constituents of The notion of getting something for perience had shown that mill wheels the Ruid continued to stream, alternate nothing that underlies all speculations could turn big grindstones or raise heavy ly spreading across the surface and then about perpetual motion is as old as Ar hammers. 'vVhy couldn't the wheel also sinking out of sight. Again he made no chimedes and may be a good deal older. drive a pump that would recycle the proposal for harnessing the motion. In classical times, however, there was mill's water supply? In Fludd's day there a tendency to depend on supernatural was little reason to deny the possibility. I loW was the tolerant attitude of early power sources. A more down-to-earth The same was true half a century later, - scientists toward perpetual motion approach to the subject grew out of eco when John Wilkins, Bishop of Chester transfOlmed into today's skepticism? nomic considerations as the first labor and an early official of the Royal Society, Clearly we now have far more theoretical saving machines, in particular water put forward his views on the subject. In knowledge and can make much more re mills, spread across Europe. Originally the 1670's Wilkins envisioned three nat fined devices such as bearings, linkages used to grind Rour, water mills evolved ural power sources that might be har and heat exchangers. Cannot this combi rapidly in later Roman times. Although nessed to provide perpetual motion. nation of talents close the apparently they were never especially popular in the These, in his words, were "Chymical Ex tiny gap between the designs of earlier Mediterranean area, quite the opposite tractions," "Magnetical Virtues" and "the times and the construction of actual was the case in western Europe. By A.D. Natural Affection of Gravity." working models? The answer, of course, 400 water-driven Rour mills and saw 'vVilkins' third power source embraces is an emphatic no. For a perpetual mo mills were common in France. Twenty the entire family of overbalanced wheels; tion machine to function, whatever its years after the Norman Conquest some that is, wheels that turn because they design, would require that it violate ei 5,600 water mills were operating in are perpetually heavier on one side than ther the first or the second law of ther 3,000 English communities, and before the other. He specifically mentioned only modynamics. the end of the 14th century in England one formula for chemical extraction; its The first law of thermodynamics-the waterpower had been harnessed not underlying concept may have arisen principle of energy conservation that only to grind Rour and saw wood but also from a misunderstood observation of the Mayer helped to formulate-can be stat to tan leather, to full woolens and to ceaseless motion of small particles visible ed in various ways. One way of putting grind pigments for paint. Soon almost in a Ruid that we know as Brownian it says that a fixed amount of mechanical every English manor that was situated movement. 'vVilkins also deSigned, but work always gives rise to the equivalent on a stream-roughly a third of all the almost certainly never tried to build, a amount of heat. Thus energy can be con manors in the Domesday Book-had its machine to utilize magnetic attraction. verted from work into heat, but it can own mill. Elsewhere Roating mills were At no point, however, did he suggest a neither be created nor destroyed. There anchored in rivers and tidal mills stood way of obtaining useful work out of the are more complex formulations of the in estuaries. proposed perpetual motions. first law but all eventually arrive at the

115

© 1967 SCIENTIFIC AMERICAN, INC same conclusion: The total energy of the boring of a cannon barrel, he conclud universe is constant. ed that the heat was due to friction. Even before Mayer, pioneer studies This was the first demonstration of the of heat phenomena by the Scottish chem connection between heat and work, but ist Joseph Black and the American-born it was soon confirmed by Humphry Count Rumford had helped to clear the Davy's experiment in which the rubbing way for deeper understanding. Black es together of two pieces of ice was shown tablished the vital distinction between to produce heat. It was a number of heat (as a quantity of something) and years, however, before the equivalence temperature (as an index of heat's in of work and heat was determined with tenSity). The interrelationship of heat, any precision. energy and temperature is a complex one that can be explained by an analogy. This brings us up to Mayer. In 1840, After rain falls into a lake it is no longer when he was 27, Mayer sailed from rain but simply water; after heat is trans Rotterdam as ship's physiCian on the ferred to a body (because of a tempera schooner Java, bound for the East In ture difference between the cool body dies. Although it is doubtful that he and its warm surroundings) it is no long knew anything about Black's work or OVERBALANCED WHEELS have been the er heat but simply energy. If the lake has Rumford's, he had brought along An most common prime movers of perpetual no outlets, the rain raises the water level; toine Laurent Lavoisier's treatise on motion n13chines. Just as the water's weight if the body cannot get rid of energy, the chemistry, and he soon became fasci overbalances a mill wheel and makes it turn, heat transfer adds to its total energy and nated by Lavoisier's suggestion that ani so various means of apparently adding thereby raises its index of heat-its tem mal heat is generated by the slow inter weight to one side of a wheel were expected perature. nal combustion of food. In Black's time variations in tempera vVhen the Java reached the East In ture and energy were attributed to the dies, 28 of its crew were ill with fever. voisier's comments was that, when the presence or absence of the intangible The treatment for fever in those days body is in warm surroundings, less in fluid called caloric. Rumford, in tUt'll, was to bleed the patient, and when ternal combustion is required to keep it struck a deathblow to the concept of ca Mayer did so, he observed that the crew warm than when it is in cold ones. In loric with his experiments in a Bavarian men's venous blood was bright red rath support of this view he and others point cannon foundry. Bringing water to a boil er than the normal dark red-almost as ed to variations in the color of venous solely with the heat generated by the red as arterial blood. Now, one of La- blood. iVlayer concluded that his pa-

MILLRACE

PUMP (ARCHIMEDES SCREW)

WATERWHEEL

CLOSED·CYCLE MILL was proposed by the English physician they required a violation of the principle of energy conservation, Robert Fludd in 1618 as a source of perpetual pow er in areas that formally known as the first law of thermodynamics, was not recog· lacked streams. The fact that such devices could not work because nized by the scientific community until two centuries after Fludd.

116

© 1967 SCIENTIFIC AMERICAN, INC to move the four machines shown above. The first device (a) was weights. A pair of buoys within a water·filled drum were expected expected to turn when jointed arms, with weights that rolled to to move weights that would overbalance the next device (c). Fi· their ends, were extended on one side; actually the wheel remains nally (el), a starkly simple design reAects the inventor's conviction exactly balanced, whether! or not the arms are extended. A much that his overbalanced wheel rim would spin between two rollers in more complex wheel (b) was designed with the same objective. spite of its lack of any support. These engravings and four on the Like a, however, it is actually in balance in spite of its shifting following pages appeared in early issues of SCIENTIFIC AMERICAN.

lients' venous blood looked like arterial ied chemistry in Manchester with John Leonard Sadi Carnot, an early student blood because, like arterial blood, it had Dalton, but soon he developed an en of the theoretical basis for the steam en a high content of oxygen. It seemed that thusiasm for experiments in electricity gine, had started with a similar axiom in the tropical East Indies the crewmen's and electromagnetism, a field in which and had reached a number of significant bodies did not consume as much oxygen he was largely self-taught. In the early conclusions concerning the dynamics of as they did in cooler latitudes. 1840's he carefully measured the amount heat. As we shall see, Carnol's work, par At this point Mayer went a step be of work required to raise the tempera ticularly his 1824 study "Reflections on yond Lavoisier to conjecture that the ture of a pound of water from 60 degrees the Motive Power of Heat," forms the body heat evolved by the metabolism of Fahrenheit to 61 degrees. Joule an basis of the second law of thermody food should be exactly balanced by a nounced his result in 1843: the amount namics. combination of two opposing factors. of mechanical energy required was 838 Proceeding from his axiom, Helm These were, first, the heat lost by the foot-pounds. In later years he refined holtz next showed that the failure of per body to its surroundings and, second, the this figure to 772 foot-pounds, a value petual motion machines led logically to work the body performed. Mayer was remarkably close to today's standard the conclusion that energy is always con soon saying that heat and work are mere (778.16 foot-pounds). served. He went on to demonstrate that ly different manifestations of energy Joule had thus quantified the relation both heat (regarded as small-scale mo (which he called "force"), and that the between work and heat that Mayer had tion) and work (regarded as large-scale two manifestations are equivalent. propounded. Four more years were to motion) were forms of energy and that The young physician was not able to elapse, however, before a third young what was conserved was the total of obtain experimental proof of his conjec investigator, Hermann von Helmholtz, the two forms rather than either heat ture; he lacked both money and labora convinced the international scientific or work taken separately. Helmholtz tory facilities. He did, however, analyze community that the first law was a valid showed that the findings of Joule's ex data collected by other investigators on generalization. In 1847, when he was 26, periments were in general agreement the specific heat of air, and he managed Helmholtz presented his formulation of with calculations of the kind made by to calculate a numerical relation between the first law before the Physical Society Mayer. Like Mayer, Helmholtz submit heat and units of mechanical work. In of Berlin in a paper titled "On the Con ted his paper to Annalen del" Physik und effect he had determined the mechanical servation of Force." He began his anal Chemie, and it too was refused. equivalent of heat. He offered an ac ysis by declaring that perpetual motion count of his work to the foremost scien machines were axiomatically impossible. I have given this brief history of the tific journal of his day, Annalen der In physics, as in mathematics, axioms are first law because it is the law that Physik uncZ Chemie, but it was refused. distinct from theorems. A theorem is a most would-be inventors of perpetual In 1842 a revised account appeared in conclusion that is logically deduced from motion machines attempt to evade. Their another journal, and Mayer's version of an axiom. An axiom does not require expectation is that more energy can be the first law of thermodynamics was for logical proof. The validity of a phYSical wrung out of some device incorporating mally put forward. "Once in existence," axiom can be based instead on repeated falling or turning bodies than is required he wrote, "force cannot be annihilated; observations of nature. Thus Helmholtz to restore the device to its original state. it can only change its form." did not need to prove his axiom; it was Curiously one of the most persistent pro enough to pOint out that no one had yet posals is Fludd's closed-cycle water mill. ames Prescott Joule, the son of a pros built a successful perpetual motion ma As late as 1871 an American patent at J perous English brewer, was born chine. Helmholtz observed further that torney noted with some asperity that four years later than Mayer. Joule stud- he was not alone in his view. Nicolas inventors submitted one or another vari-

1 17

© 1967 SCIENTIFIC AMERICAN, INC ation on Fludd's mill to him every year, ney. It is easy enough to find the flaw in lost to friction and, in this case, to elec inquiring whether the concept was pat Wilkins' proposal today: any lodestone trical resistance as well. entable. Over the years, however, de strong enough to pull the ball up the It is scarcely surprising that the chi vices that depended for their power on ramp would be too strong to let it fall mera of perpetual motion has attracted overbalanced wheels gradually aban back to its starting point. not only savants and optimists but also doned running water in favor of inge A 19th-century device solved a sim rascals. One of the many outright frauds nious weight-shifting systems. ilar problem by incorporating an electro in the history of perpetual motion ma Many inventors have preferred power magnet that was alternately turned on chines was perhaps the most elegant sources more sophisticated than the over and off. When the circuit to the magnet overbalanced wheel ever built. It was balanced wheel. Both early and late they was closed, the magnet's attraction was the work of a skilled Connecticut ma have turned to magnets, at first natural supposed to pull a connecting rod that chinist, E. P. Willis. A large gear wheel, magnets and then electrically powered acted through a crank to impart rotary mounted at an angle to the horizontal ones. Bishop Wilkins' design for a mag motion to a disk. The spinning of the and fitted with a complex system of netic device depended on a lodestone, disk between two brushes was then ex weights, purportedly drove a smaller which was to be strong enough to pull pected to generate enough electricity to hollow flywheel.After the machine had an iron ball up a ramp. Just before the energize the magnet. Once the machine attracted much attention in New Haven, ball had climbed all the way up to the was started by hand the inventor expect where Willis charged admission for lodestone, it would drop through a hole ed it to run forever, or at least until the viewing it, he moved it to New York in and roll back down a curved second contact points on the switches wore out. 1856. There the same attorney who was ramp. The ball would then pass through As so often happens in the design of per to comment on the perpetual rediscov a door and reach the first ramp again, petual motion machines, the inventor ery of Fludd's water mill went to see it. where it would resume its upward jour- had made no allowance for the energy The exhibitors, he noted, were careful

FRAUDULENT MACHINE that purported to demonstrate per. that the uphill weight extended beyond the wheel's perimeter. petual motion was built by a Connecticut machinist in the 1850's. The resulting imbalance was said to be sufficient to keep the Ostensibly each pair of rod·linked weights that rested atop the wheel turning and to drive a flywheel (left). Actually compressed tilted wbeel (right) was shifted in position as the wheel turned, so air passed through a strut (A, far left), turning both of the wheels.

118

© 1967 SCIENTIFIC AMERICAN, INC not to claim that Willis had achieved perpetual motion; rather, they chal lenged any visitor to provide another explanation for the machine's motion. Although a glass case kept viewers from inspecting the machine closely, the at torney noted that there was a suspicious ly nonfunctional strut below the edge of the hollow flywheel.Evidently a steady flow of compressed air, undetectable outside the glass case, kept the flywheel turning. Thus it was actually the fly wheel that drove the overbalanced wheel, rather than the reverse. The Willis fraud, Fludd's water mill and all similar devices are based on the assumption that the first law of thermo dynamics can be violated. Some perpet ual motion machines, however, do not violate the first law; neither friction nor electrical resistance is a significant prob lem in their design. They are nonethe less impossibilities because they attempt instead to circumvent the second law of thermodynamics.

The foundation of the second law was laid down by the observations of Car PERPETUAL MOTION powered by "Magnetical Virtues" was to be achieved by a steel not, and the law was first fully formu bullet as it rolled up and down a pair of ramps according to a design proposed by the Bish lated by the German physicist Rudolf I>P of Chester in the 167.0's. The lodestone placed on the top of the pedestal was expected to Clausius. The first law, as we have seen, draw the bullet up the straight ramp, whereupon it would fall through a hole and ro ll back to its starting position. The bishop did not propose harnessing the device to ohtain power. demonstrates that a fixed amount of mechanical work can always be convert ed into the equivalent amount of heat. But the most casual observation of a heat engine in operation-for example a steam engine-makes it plain that the reverse of the first law's axiom is not pre cisely true: a fixed amount of heat can not be completely converted into the same amount of work. When heat is transformed into work, some of the ini tial energy is unavoidably wasted. In the case of a real steam engine operating in the real world, some of the wasted energy goes to overcoming friction, some is lost through warming the engine and the surrounding atmosphere, some through leakage and some through other a ven ues of dissipa tion. Carnot wanted to find out whether improved design could eliminate all steam engine losses. He created in his imagination an ideal engine; it was leak proof, completely insulated and friction less. He then ran the imaginary engine through a full operating "cycle" (a con cept, by the way, that Carnot was the first to develop). In one ideal cycle water is heated until it vaporizes into steam, and the pressure of the steam forces the engine's piston to move; the PERPETUAL MOTION powered by electricity was often favored by 19th-century inven cycle is completed when the expanded tors. In this design the attraction of an electromagnet worked through a crank to turn a steam cools and condenses into water wheel; the wheel's rotation was then supposed to generate enough electricity to work the again, allowing the piston to return to magnet. As usual the inventor neglected to allow for the losses from friction and resistance.

© 1967 SCIENTIFIC AMERICAN, INC "' / its starting position. Thinking through the steps in this ideal cycle, Carnot re alized that a complete conversion of AMMONIA VAPOR heat into work was impossible; an un avoidable loss of thermal energy oc cUlTed in the process of cooling and con densation. The language Carnot used to state his conclusions is strange to our ears be f- Z cause, like others in his day, he talked w :?: about heat in terms of caloric. ''''hat z » BOILER he had to say was nonetheless the earli 0 0:: est statement of the second law. The > Z transformation of heat into motive pow w AMMONIA er, CaI'not wrote, "is fixed solely by the :?: RETURN LINE 0 temperature of the bodies between 0:: LL which is effected ...the transfer of the » � caloric." This is to say that, in order to do w I work, heat must "run downhill" as water does and, just as with water, the farther it runs downhill, the greater the amount of work it does. This is the concept we express today by saying that heat must be transferred from a higher tempera ture to a lower one to do work.

Building on Carnot, Clausius applied the word "entropy" (from the Creek for "turning") to the index used to mea sure the amount of heat that is un avoidably lost. The modern formulation of the second law that says that en AMMONIA h:Jpy always increases arises from the VAPOR earlier realization that heat is a down hill How. Because the supply of energy in the universe is a constant that cannot be increased or decreased, and because dt the same time the downhill How of heat is accompanied by inevitable losses, f- == Z w a time will inevitably come when the en :?: » tire universe will be at the same temper z BOILER 0 ature. 'With no more hills of heat and 0:: :> therefore, in Carnot's terms, no further z w AMMONIA transfers of caloric, there can be no :?: RETURN LINE work. This inevitable end, sometimes 0 0:: called the "heat death" of the universe, LL » concerns us here because perpetual mo � w tion machines that attempt to violate the I second law are expected to achieve a localized halt in the inevitable increase of entropy and produce a decrease of entropy instead. » The fact that, on the average, entropy continually increases does not, of course, rule out the possibility that occasional local decreases of entropy can take place. It is only that the odds against such an event are extraordinarily long. The bed of a river could suddenly cool, yielding AMMONIA ENGINE of the 1880's, designed by John Gamgee, was based on the expectation its energy to the running water, and this that free power would be produced because heat transferred from the surroundings would energy could be applied in some way to turnthe ammonia from liquid to �2S. The gas pressure is enough to drive a piston (top). When the gas then expanded in the cylinder (bottom), the inventor expected that it would make the water run uphill. But riverbeds condense spontaneously and return to the boiler as a liquid to repeat the cycle. He did not do not cool and water does not run up anticipate the need to refrigerate the return side of his engine in order to convert the ammo hill. A similar loan of thermal energy nia produces. gas to liquid. The energy needed to do this, of course, is more than the engine from the river's environment could ai-

120

© 1967 SCIENTIFIC AMERICAN, INC "GENERATOR" AND "MOTOR" of a supposed perpetual motion the generator (left) turned tap water into high.pressure "etheric device were exhibited in Philadelphia for more than a decade late vapor" when "vibratory energy" was applied. After Keely's death in the 19th century. The inventor, John E. W. Keely, contended that the totally fraudulent device was fouud to run on compressed air.

low the water to dissociate spontaneous reasoned that the transfer of heat from motor to the Secretary of the Navy, in ly into hydrogen and oxygen. But the the environment, rather than the energy spite of the fact that scholars had point water does not dissociate spontaneously. supplied by the combustion of fuel, ed out that the engine fatally violated Furthermore, an old man on the river would be enough to transform the am the second law. OfficialWashington bank, watching the water flow by, could monia working fluid hom a liquid to a came close to embracing the inventor. grow younger rather than older, but he gas. He reasoned further that the am The Secretary of the Navy was not the doesn't. Rivers continue to flow down monia gas, on driving the piston back only high official who inspected a model hill, H20 remains water and man inev and expanding, would cool, condense of the zeromotor with interest; so did itably ages. The chemist Henry A. Bent and drain into a reservoir, whereupon other Cabinet members and President has calculated the odds against a local the cycle could begin again [see illustra Garfield himself. Isherwood's gullibil reversal of entropy, specifically the prob tion on opposite page J. ity may be hard to understand, but not ability that one calorie of thermal energy Anyone with the slightest knowledge his interest. This was an era when in could be converted completely into of Carnot's cycle, let alone the second order to keep the U.S. fleet at sea it was work. His result can be expressed in law of thermodynamics, could scarcely necessary to maintain a complicated terms of a familiar statistical example: take such an idea seriously, yet Gamgee and expensive network of coaling sta the probability that a group of monkeys and his supporters were undoubtedly tions abroad. If the Gamgee engine hitting typewriter keys at random could sincere. They had either incorrectly cal had worked, coaling stations could have produce the works of Shakespeare. Ac culated or failed to calculate the zero been forgotten and all the energy the cording to Bent's calculation, the likeli motor's temperature requirements. The Navy would have needed to power its hood of such a calorie conversion is heat transfer from the environment was fleet could have been provided by the about the same as the probability that indeed sufficient to convert ammonia thermal energy contained in the seawa the monkeys would produce Shake from a liquid to a gas, but this advan ter in which the ships floated. speare's works 15 quadrillion times in tage is nullified in the system as a whole The surprisingly wide acceptance of succession without error. by the cooling of the gas on expansion. proposals such as Gamgee's can be ex Starting at zero degrees C. and a pres plained, of course, by general ignorance It is against these odds that the would- sure of four atmospheres, the tempera of known principles. As early as 1775 the be inventor of a perpetual motion ture of the gas has fallen to -33 degrees French Academy of Sciences passed a heat engine must struggle. One such in by the time its volume has quadrupled. resolution refUSing to entertain any fu ventor was John Gamgee, who was ac If the gas is to condense into a liquid, ture communications concerning perpet tive in Washington, D.C., during the both the condenser and the reservoir ual motion. The U.S. Patent Office has 1880's. He developed a heat engine that must be at a temperature lower than long declined to examine applications he called the zeromotor because its nor -33 degrees. Gamgee had not provided for patents covering perpetual motion mal operating temperature was zero de for this cooling, and if he had, the cool machines unless the applicant furnishes grees centigrade. The zeromotor was not ing process would of course have re a working model or "other demonstra unlike an ordinary steam engine except quired more energy than the zeromotor tion ... of the operativeness of the in that the working fluid was ammonia could produce. vention," a ruling that has produced rather than water. Liquid ammonia va One of Gamgee's principal supporters much hostile correspondence but no porizes into a gas at a low temperature, was B. F. Isherwood, Chief Engineer of working models. In spite of such official and at zero degrees C. the gas exerts a the U.S. Navy. In March, 1881, Isher opposition public sophistication regard pressure of four atmospheres. Gamgee wood reported favorably on the zero- ing the possibility of building perpetual

121

© 1967 SCIENTIFIC AMERICAN, INC motion machines was slow to develop. Perhaps the most ingenious, and cer tainly the longest-lived, swindle involv ing a supposed perpetual motion ma chine began in 1875, when John E. W. To preserve your copies Keely unveiled a combined "genera tor" and engine at his home in Phil adelphia. There was nothing unusual SCIENTIFIC about Keely's engine, which was a varia tion on the conventional steam engine. of AMERICAN Keely's generator, however, was extraor dinary. It was an elaborate combination of metal globes, tubes, petcocks, nozzles, valves and gauges, but its operation was deceptively simple. Keely would blow � A choice of handsome and durable library files-or bind into a nozzle for half a minute and then ers-for your copies of SCIENTIFIC AMERICAN. pour five gallons of tap water into the generator through the same nozzle. After i �r Both styles bound n dark green library fabric stamped turning various petcocks and valves he in gold leaf. would show onlookers a pressure gauge indicating that the generator was full of �r Files-and binders-prepacked for sale in pairs only. a mysterious "vapor" with a pressure of

Index for entire year in December issue. * 10,000 pounds per square inch. "People have no idea of the power in water," Keely would say. "A bucket of water has enough of this vapor to produce a power FILES shown at left sufficien t to move the world out of its course." Hold 6 issues in each. Single copies easily accessible. Keely and his associates formed the . Keely Motor Company, capitalized Price: $3.50 for each pair at $1 million. They raised much of the (U.S.A. only). money from gullible New York business

Address your order, enclosing men. As the years passed, although no check or money order, engines other than the first one were to: Department 6F ever built, Keely's showmanship became more polished. By 1881 he had begun to attribute the production of vapor to "vi bratory energy," and he would "vivify" the vapor during demonstrations with a giant tuning fork. By 1884 he had so mastered what he now called the "ether ic vapor" or the "interatomic ether" that BINDERS shown at right he demonstrated a new device: a can non, complete with a "vibrator" near Hold 6 issues in each. the breech, that was capable of propel Copies open flat. ling a ball 500 yards with a muzzle ve locity of 500 feet per second. Price: $4.50 for each pair Keely died in 1898. The son of one of (U.S.A. only). his major backers promptly rented his Address your order, enclosing Philadelphia house and explored the check or money order, premises in the company of reputable to: Department 68 witnesses, seeking evidence of fraud. Under the floor of the house the search ers found a three-ton metal tank that had eviden tly served as a reservoir for New York City residents please add 5% sales tax compressed air. In the walls were found Other NYS residents please add 2% state sales tax plus local tax quantities of brass tubing, and a false

*Supply of back copies of SCIENTIFIC AMERICAN is limited. To replace ceiling suggested the means by which missing copies, mail request with your order for files or binders. Keely and his associates had conducted the compressed air to his generator. Whatever other laws he may have brok SCIENTIFIC AMERICAN, 415 Madison Ave., New York, N. Y. 10017 en in his long career, Keely had left the first and second laws of thermodynamics inviolate.

122

There are many people who buy And that's what the Hasselblad Firstly, the 500C. This could in the Hasselblad System, all by and use a car just to get from is. The best designed and built almost be called the "work Ca rl Zeiss, mak ers of sup erb point A to point B, and who buy camera in the world. horse" of the Hasselblad System. quality optical glass for genera any piece of mechanical equip Many people have bought a It is the standard body in the Sys tions. The lenses rang e from a ment strictly on the basis of it Hasselblad after just holding tem and takes all the lenses and 40mm wide angle, to a 500mm performing a particular func one in their hands for a couple magazines that are available telephoto. Every lens has a built tion with the minimum of in of minutes. They seem to know for the Hasselblad. No single in Synchro Compu r shutter with volvement on their part. instinctively that it will take camera has been used and provision for flash and strobe For this kind of person there is great photographs. And, if even praised more by the top profes synchronization at alll0 shutter a certain kind of camera , the furth.er proof is needed, not only sional and amateur photog speeds, from 1/500 of a second kind that does all the thinking has a Hasselblad been carried raphers than the 500C. The to 1 second. for hi m. Film is loaded in the on every NASA space flight, but other two bodies are more One of the most striking fea form of a cartridge, a button is more top professiona I photog "special purpose" cameras. The tures of the Has selblad System pressed ...and that's all; total raphers use Hasselblad than 500EL, which is an electrically is the interchangeable film non-involvement. any other camera in the world. driven camera al lowing for magazines, each one of superb ra pid exposures and remote con Now don't mi sunderstand us, The basic Hasselblad camera design and construction. The trol, and the Superwide C wide we are not criticizing either the is really ju st part of a com beauty of these magazines is angle camera. No other camera person or the camera . They pletely integrated and inter that with just one camera body, using the square format both will probably be very happy changeable system of camer a 2'14/1 a photographer can shoot pic has as wide an angle of view as with each other ... But, there is bodies, film magazines, lenses tures in black and white. Then, the Superwide C. On its intro another kind of person. The and accessories. before finishing the roll, change duction, this camera was hailed to a magazine loaded with color, kind who buys a fine automobile, The film format used in the Has as a breakthrough in camera shoot a few color shots, then go not just to get from po int A to selblad System is 2'14" square. design. There are seven lens es back to black and white film. point B, but also for the great This has been described as the One magazine even allows you pleasure he gets from actually "ideal" format, and with good mm to make 70 exposures on one driving it. For this kind of per reason. It's big enough to give 500 ------______go roll of film. Hasselblad was the son there is also a certain kind you pictures of superb quality first camera system to offer the of camera ...the Hasselblad ... and definition, and yet small adv�ntage of interchangeable A camera that doesn't do all the enough to al low the design ,and magazines. thinking for you. 8 physical shape of the camera 250 ------_-+--+-_------1 ° The Hasselblad is a camera for to be as compact as it is. There are many many acces the kind of person who buys a sories in the Hasselblad System, The Hasselblad uses the single piece of mechanical equipment, each one designed and built to lens reflex viewing system. The 150 ------29° not just to pe rform a particular the same extreme standards of beauty of this method i s that function, but als o for other, --- .-- 36° quality and craftsma nship that you see the object you are goi ng 120------almost intangible, rea sons. For Hasselblad has become famous to photograph on a large 2'14" the feel, the look, the touch, for. square ground glass viewing 80------52° sometimes even the smell of it. Shown below are ju st a few screen, as you look through the Certainly he could give you very 50------75° items in the System. actual lens that will take the , -, sound, logical reasons for buy 40 --- -- 88° picture, so you always know ex Like all good things in'life, the ing it and probably spending actly how your finished picture Hasselblad is expensive, but if much more money than he will turn out. you're the kind of person we would pay for the simpler, non have been talking about (and There are three bodies in the involving "push-button" model, o you wouldn't have read this far Hasselblad System, each one but none of these wou Id be the if you weren't) then, who knows, designed and constructed to Interchangeable Lenses. This dia real reasons. o with this kind of camera, per perfor m its own particular gram illustrates the focal length (/.) The real reason is very simple and the angle of view (r .) of the haps you could live on love function better than any other he fell in love with it. Many men seven lenses av ailable in the Hassel· alone. camera of its type. b/ad System. (and a very few lucky women) fall in love with a beautiful ma chine. To these men, there is something about a piece of If you would like more infor equipment that not on ly looks, mation and a free 40 page but feels good and performs its catalogue, write to: Paillard In function better, because it's corporated, 1900 Lower Rd., designed and built better than Linden, New Jersey 07036 anything else in the world HASS£lBlAD