action of steam, to force the weights out on one side and by its condensation to raise and to withdraw the weights on the opposite or ascending side.*

31. Orffyreus' invention of a wheel, moving either way, and raising as much as 70 lbs. weight, would have gained more respect had he not abandoned his scheme, and never reverted to it during the remaining years of his life. As he was versed in clockwork, he may have employed, in some ingenious way or other, a powerful spring, capable of being reversed; adding small balls to make a tapping noise as the wheel revolved, merely to act as a blind, to conceal the real source of motive power.

In 1860, Dr. E. HENDERSON proposed the following feat

E

d

b

to perpetual motion seekers, in preference to more complex theories:-A, a, a board having a semicircular path B, b, cut out of it; C, a horizontal or level line from the centre of the ball D, to E. The ball D, on rolling down

* Although this is a novel view of the case in relation to this parti cular invention, it receives some confirmation from the fact that the Marquis's Fire Engine,' or 'Water-commanding Engine,' had been designated as a 'Perpetual Motion' early in the following century, when a small quarto was published, with the title:-"A new and rare invention of Water-Works, teaching to raise water higher than the spring, by which invention the Perpetual Motion is proposed, and many hard labours performed. By Isaac de Caus, Engineer. As also a Description of Captain Savory's Engine for raising of vast quantities of water by Fire. London: printed for G. Moxon, at the Atlas, in Warwick Lane. 4to. 1704." Pp. 47. And the engine as exhibited at Vauxhall in 1663, was also referred to by Dr. Hook as a "Perpetual Motion." But while those engines were for raising water, the weighted wheel might be intended for moving machinery, and thus be the first application of steam for that special purpose. See 'Life of the Marquis of Worcester.' 1865.

the curve B, b, its impetus will cause it to rise below E; if, however, it could be made to rise to d, the object sought would be attained, as the ball might then return to D, down the incline d, D, and so on continually, until the materials were worn out.

32. But perpetual motion seekers usually demand some more abstruse mathematical or mechanical demonstration. Now to the learned in any matter whatever, be it in literature, art, or science, there are certain established facts which it would be a sign of absolute impotence to attempt to overturn; and which no professor would seriously, or at any length attempt to argue upon, against the opinions of weak-minded enthusiasts. It is much the same in mathematics and in mechanical philosophy. Who cares to enter into interminable arguments with the squarers of the circle, or with the contrivers of mills to work themselves and pump their own waterpower? If it is a folly to propose such impotent labours, it is equally a folly to discuss them with men who congratulate themselves on their own superior mental qualifications. It is a very natural course on the part of their opponents, to require the production of the lifelike machine, instead of merely talking about it. Surely in seven centuries something should have been done to put a spoke in this ever-talked-of wheel, to keep it turning, instead of always having recourse to the stale subterfuge, that only this, that, or something else is all that is wanting. If this seemingly easy project is still so difficult, we may fairly infer, when supported by the highest scientific authorities against it, that it is really a fallacy; and that its followers are irretrievably in the wrong, working in the dark, bungling at every step, beset with mortifying and humiliating failures; and instead of showing the least progress, never effecting more than a mere resurrection of bygone mechanical vagaries.

PERPETUUM MOBILE;

OR,

SEARCH FOR SELF-MOTIVE POWER.

CHAPTER I.

EARLY OPINIONS RESPECTING THE POSSIBILITY OF, AND PROJECTS FOR OBTAINING, PERPETUAL MOTION.

THE most ancient recorded scheme for effecting a mechanical perpetual motion that we have been able to trace, belongs to the thirteenth century. Its inventor was WILARS DE HONECORT, an architect, whose original Sketch Book, in which his design appears, as reproduced in the annexed engraving, is deposited in the École des Chartes at Paris. In 1849 M. Quicherat published a commentary, as did also M. Lassus in 1858, on that remarkably interesting art relic. Translations of these, with additions of his own, appeared in 1859, by Professor Willis, of Cambridge,* to whose valuable work we are indebted for the following particulars on the subject under review.

At page 35, appears Plate VIII., Recto† of the Fifth Leaf, marked in the thirteenth century with the letter 1, and in the fifteenth with the letter e.

“Maint ior se sunt maistre dispute de faire torner une ruee

* Facsimile of the Sketch-Book of Wilars de Honecort, an architect of the thirteenth century; with Commentaries and Descriptions by M. J. B. A. Lassus, late architect of Notre-Dame, and of the Sainte Chapelle at Paris, &c.; and by M. J. Quicherat, Professor of Archæology at the Ecole des Chartes at Paris. Translated and edited by the Rev. Robert Willis, M.A., F.R.S., &c. 4to. 1859.

tRecto and verso are terms employed to distinguish the drawings in the Sketch-Book, from their being made on both sides of the leaf.

B

par li seule. Ves ent ci con en puet faire par pers ou par vif argent.'

mailles non

"Maint jour, se sont maîtres disputés pour faire tourner une roue par elle seule. Voici comment on peut le faire par maillet non pairs ou par vif-argent."

66

Many a time have skilful workmen tried to contrive a wheel that shall turn of itself: here is a way to make such a one, by means of an uneven number of mallets, or by quicksilver."

Wilars de Honecort presents to us a device for a perpetual motion; it is not clear whether he intends to claim the contrivance of it, or whether he had met with it in the course of his travels. It differs very little from a well-known contrivance for this purpose which has been so often published, and its fallacy so fully explained in popular books,* that it is unnecessary to dwell at length upon the mechanical principles which it involves. It is extremely curious in this place, because it shows the great antiquity of the problem, the solution of which has wasted the time, the brains, and the means of many an unhappy artisan or philosopher.

In the drawing we have now before us, the two upright posts, which are framed together and skilfully braced so as to ensure their steadiness, support between them a long horizontal axle, to the centre of which is fixed a wheel with four spokes. The absence of perspective in this drawing makes the wheel appear as if it were parallel to the frame, instead of being, as it is, at right angles to it.

Seven mallets, or arms, each loaded with a heavy weight at the end, are jointed at equal distances to the circumference of the wheel, so that those which happen to have their joints below the diameter of the wheel will hang freely down, but if the wheel be turned round by hand or otherwise, the weights of those which are on the ascending side will in succession rest on its circumference, and will in that position be carried over the highest part of the wheel, and downwards on the descending side, until the arms that bear them are brought into a vertical position and a little beyond it, and then the

*For example, in Ozanam's or Hutton's 'Mathematical Recreations.' M. Lassus has supplied an elaborate description, with demonstrations of the fallacy of this class of contrivances, which I have ventured to suppress, as it is to be found in books of such easy access as those I have referred to, and would scarcely be intelligible to persons unacquainted with mathematics.-(W.)