Vol. XXIII. No. 8.] 



POPULAR SCIENCE NEWS. 



117 



Practical Cljoi^istry arjd tlje ^rts. 



[OrigiiKii in The Popular Science News.'\ 

 PERPETUAL MOTION. 



BY H. A. EV.\NS. 



The search for a perpetual motion machine began 

 at an early period in the history of the human fam- 

 ily, and has been kept up with unflagging zeal, 

 until, at the present time, there are few men in civil- 

 ized countries who cannot boast of the acquaintance 

 of a crank or of a fraud who has solved, or is about 

 to solve, the problem. While much damage to 

 individuals has resulted from this search, it has 

 been, on the whole, of benefit to the world. For, 

 as from the attempts of the old alchemists to trans- 

 mute metals, we have much valuable chemical 

 knowledge, so from the search for perpetual motion 

 there grew up the greatest of all the generalizations 

 of physical science — the doctrine of conservation of 

 energy. But, while the chemist will admit that in 

 the future, when we have learned what an element 

 is, it may become possible to convert lead into gold, 

 the mathematician knows that perpetual motion is 

 forever an impossibility. 



Doubtless the idea was suggested to the first per- 

 petual motionist by the apparent movement of the 

 sun. Believing motion to be caused by a spirit, it 

 was as reasonable to think that that spirit could be 

 made to operate a pump as well as move the sun. 

 The problem was a perfectly legitimate one, and 

 occupied the attention of philosophers. In latter 

 days, men have continued the search, stimulated 

 by the prospect of obtaining a fabulously large sum, 

 which they imagine to have been offered bv some 

 government; or frauds have pretended to have 

 solved the problem, hoping to make money out of 

 unwary investors, and have been — and still are — 

 singularly successful in doing so. 



The subject is one of great historical interest, 

 though there is a wonderful degree of sameness in 

 all of the devices proposed, and the most popular of 

 all — the over-balancing wheel — dates from before 

 the thirteenth century. As a rule, the inventions 

 are never characterized even by mechanical inge- 

 nuity. This, however, is what we would expect, 

 for, usually, the iijyentors are wholly superficial, 

 seeking a short road to fame and wealth. In some 

 cases, as in an invention now before the public, the 

 makers bewilder themselves, as well as their patrons, 

 by the complexity of their devices. 



At an early date, scientific men lost faith in the 

 possibility of perpetual motion, and, as early as 

 ^SIS' Stevinus assumed it as an axiomatic impossi- 

 bility. Newton states in the I'rincipia, as a deduc- 

 tion from his third law of motion, that it is impossi- 

 ble with the ordinary mechanical arrangements, 

 thus foreshadowing the principle of conservation of 

 energy. I)e La Hire is usually incorrectly given the 

 credit of having first given proof of its impossibility, 

 although his proof was not published until 1678, — 

 long after Newton's. In 1843, Joule completed 

 Newton's work, and showed that the principle of 

 conservation of energy held true, not only for the 

 forces for which it was announced by Newton, but 

 for any force. In 1775, the Paris Academy of 

 Sciences refused to consider any scheme which pre- 

 tended to do work without a corresponding expen- 

 diture of energy, saying in tfteir announcement : 

 " * * * This species of research has the incon- 

 venience of being costly; it has ruined many a 

 family; and numerous mechanics, who might have 

 done great service, have wasted on it their means, 

 their time, and their talents." 



About the only machines which have ever suc- 

 ceeded in permanently deceiving anyone but their 

 inventors, were those of the Marquis of Worcester 

 and of Councillor Orffyrcus. That of the Marquis 



is described as follows in the Century of Inventions: 

 "An Advantageous Change of Center. — To prouide 

 and make all ye weights of ye descending syde of a 

 wheele shal be perpetually further from ye center 

 than those of ye mounting syde, and yett eqvall in 

 number and heft of ye one syde as ye other. A 

 most incredible thing if not seen, but tryed before 

 ye late King of happy and glorious memorye in ye 

 Tower by my directions, two Extraordinary Embas- 

 sadors accompanving his Matie and ye D. of Rich- 

 mond, D. Hamilton, and most part of ye Court 

 attending him. The wheele was 14 foote ouer, and 

 40 weights of 50 pd. apiece. Sir Wm. Bedford, then 

 Lieut, of ye Tower, and yett lining, can justif3' 

 it with seuerall others; they all saw that noe sooner 

 these great weights passed ye Diameter Line of ye 

 vpper syde butt they hung a foote further from ye 

 center, nor noe sooner passed ye Diameter Line of 

 ye lower syde butt they hung a foote nearer; be 

 pleased to judge ye consequence." It is probable 

 that this account has caused man^' to try to "redis- 

 cover" this lost_ invention. 



Orffyreus, whose real name was Bessler, con- 

 structed a wheel 12 feet in diameter, and over a foot 

 thick. It consisted of a light framework, covered 

 with cloth, so as to entirely conceal the interior. 

 This machine, when set going in either direction, 



Fig. I. 



constantly accelerated its velocity until it reached 

 twenty-five revolutions in a minute. It is said that 

 it was placed in a room in the castle of the land- 

 grave of Hesse-Cassel, started, and then, the room 

 being sealed, to have still been going when the 

 room was opened, eight weeks later. Of course 

 there must have been some arrangement concealed 

 inside the wheel which caused it to revolve. This 

 wheel is principally remarkable, however, as having 

 caused the mathematician, S. Gravesandc, to write 

 to Newton that he thought the problem of perpetual 

 motion had been solved by it. Afterward, upon the 

 inventor's refusal to allow him to examine the inte- 

 rior of the wheel, he announced that he had been 

 deceived. 



The devices which have been suggested as perpet- 

 ual motion engines may all be described as combi- 

 nations of machinery run by weights, so arranged 

 that a descending weight elevates another of equal 

 weight, or by springs that rewind themselves. Or, 

 in other words, a perpetual motion machine must 

 be capable of creating energy. Those machines 

 which depend on some natural power, as rains, 

 change of temperature, tides, etc., are in no sense 

 perpetual motion devices, as they depend for their 

 motive force upon stored up energy, which is con- 

 stantly renewed. 



Fig. i. 



As before stated, there is much sameness in the 

 inventions put forward, as is seen in the illustrations 

 accompanying this article. Nine-tenths of those 

 offered in the past have been derived directly from 

 the over-balancing wheel, and it is itself rediscovered 

 annually. 



In its best form, the over-balancing wheel (Fig. i) 

 consists of a light wheel, from 6 inches to 20 feet in 

 diameter, having from seven to one hvmdred weights 

 attached to its circumference. These weights are so 

 arranged that the wheel being started to revolving 

 from left to right, each weight will fall out from the 

 wheel as it passes below a line (LM) representing 

 the horizontal diameter. As they pass the point (N) 

 they will approach the circumference by their own 

 weight. The idea is, that on the right-hand side 

 there are constantly some weights further from the 

 centre than those on the left, and that they thus 

 having a greater leverage, the motion of the wheel 

 will be continued. The 

 inventor who hits on this 

 is satisfied that he has at 

 last succeeded, and is only 

 undeceived when, after hav- 

 ing a model constructed, 

 it quickly stops, after hav- 

 ing been set in motion. 

 That it will not run, how- 

 ever, i» easily demonstrated 

 without going to the ex- 

 pense of having a model built. A wheel will 

 remain in equilibrium when the force tending to 

 cause motion is just equalled by another force 

 acting in a contrary direction. Or, in the 

 case of a pair of scales, in which W represents 

 the weights used, and w the length of the arm on 

 that side of the balance ; and R represents the object 

 to be weighed, and r the length of the arm on that 

 side, then the scales will be in equilibrium when 



Rr=Ww. 



That is, a machine will be in equilibrium when the 

 force tending to move it, multiplied by the leverage 

 of that force, is just equalled by the product of the 

 resistance by its leverage. In Fig. i, the weights A, 

 B, and C, tend to cause rotation of the wheel from 

 left to right, and are counteracted by the weights D, 

 E, F, and G. The leverage in each case is the short- 

 est distance from the weights to a vertical line pass- 

 ing through the centre of the wheel. If the sum of 

 the products of A, li, and C, by their respective dis- 

 tances from the vertical line (HI), equal the sum of 

 the products of D, E, F, and G, by their distances, then 

 the wheel will be motionless. 

 As a matter of fact, in the 

 case of Fig. i, the sum of 

 the products of A, B, and C, 

 by their leverage, is less than 

 that on the other side, so 

 that the wheel will start to 

 move in the wrong direction 

 — backward. It will move in 

 that direction until the point 

 K is on the vertical line. If 

 Fig.. I be revolved from right 

 to left until the vertical line 

 passes through K and the 

 centre of the figure, and each 

 weight (which may be called 

 one) be multiplied by its dis- 

 tance from this line, it will be found that the sum 

 of those on the left equals those on the right, and 

 it then follows that the wheel will remain stationary. 

 The over-balancing wheel in Fig. i disproves the 

 statement which is frequently made that a machine 

 which will start itself solves the problem of perpet- 

 ual motion. There are only seven positions in 



1' 'g- .i- 



