The subject of Perpetual Motion claimed some of his attention. He wrote in defense of its possibility. The substance of what he said, translated into English, is as follows:
Let the centre of the universe then, or of gravity, be A, and the gnomon A B C, of which the extremity A is pierced and traversed by an axis going through the centre of the world, so that it may turn and revolve freely and easily around the said centre; to the other extremity of the gnomon, C, let a phial full of water be attached.
The weight C will turn around the centre A and will first come to D, thence to E, thence to F and G; then it will return to C, having described a complete circle, C D E F G; then it will again move to D, E, F, etc., and so perpetually, since there is no reason for its stopping in any point of the circle rather than in another.
That indeed the weight C affixed to the gnomon will move from C to D, is proved by daily experience, by which it is established that a gnomon so contrived and placed erect on any flat space, will not be able to stand, but the arm B C, C preponderating, will move towards D.
It may in the second place be proved, that if, on the other hand, another arm B G be added to the gnomon, equal in weight and similar to the other, the whole G B C A will remain motionless in equilibrium; therefore the arm B G being taken away and equilibrium being destroyed, the arm B C must move in the opposite direction.
The above, from Scheiner, called forth the following from Schott, who was also an eminent mathematician:
Whether there could be a perpetual artificial motion around the centre of the earth?
We have treated this question in our Hydraulico-pneumatic Mechanics, Part 2, Class 2, Machine 13, not however universally, but only in one particular case, that of the Gnomon of Scheiner. For P. Christopher Scheiner, in "Mathematical Disquisitions," in Number XV., Corollary 4, asserts Perpetual Artificial Motion not to be repugnant to Nature, and attempts to prove it in the following manner. Let a gnomon of a certain weight A B C be suspended around A, the centre of the universe, and bound to the beam D F, which is supported by the columns D F and E G and turns at the pole D or E; or let it be fixed at the poles, but the gnomon revolving at A.
These being the conditions, I say that the gnomon A B C will revolve from C to H and towards I, thence will return to C, thence to H as before, and so on perpetually. The cause of this continual motion is the forcible suspension; for the whole gnomon preponderates in C on account of the perpendicular tangent B A; which effect becomes more marked if a globe of iron S be supposed suspended at C. As therefore the whole of this mass, as well from the supports of the balance as from the momentary diameter, hangs suspended at C, and the vertex A, on account of the firm beam D E, cannot fall from the centre of the universe; it comes to pass that all points as well of the globe S, as of the gnomon A B C, with a continual motion turn round A; but because, by the line B A in the fixed point A, they are held from falling to the centre; therefore the greatest force of that tendency is exerted in the line B, and induces it to inclination; which inclination on account of the continuous solidity of the gnomon cannot be at all abated, so that the whole impetus is exerted either at the point A about the movable beam or at the movable poles of the beam D and E; which poles being free in their sockets D and E, abandon themselves to the motion of Nature, and thus do not in any wise hinder a perpetual circular motion. What indeed is self-evident in this, reason confirms, and daily experience in statics manifests. For if a short gnomon stand either on the terrestrial superficies M N, O P, or Q R; it will always fall towards the part C, or N, by the preponderating portion M K C; which is manifested in daily experiments.
Thence it is evident that if the gnomon were entire, the force which it exerts at N would pass into the line B A still hanging over the centre. And this is one argument. The other is from the contrary. For if an equal and similar gnomon were attached towards the part D, then the whole mass hanging on its centre would remain in equilibrium and there would be no motion; consequently the one half being taken away, the other would necessarily move according to the laws and experience of statics. If the shortened gnomon M B C N were bound only to the point M, the rest being left free, it would certainly revolve, and in the same case, the point C would describe almost a semicircular arc till, coming down to a perpendicular position, it would there remain.
Now as the force of the entire gnomon falls in the vertex A, there would be an entire and perpetual revolution around A. Much more would this be the case if on the centre C stood either the small curve A C L A or the larger one A K C, or finally the globe S alone, hanging from two iron rods A B and B C, or from one arc, A N C. From this, therefore, it may be demonstrated that a perpetual circular motion is possible.
In 1825, the following was contributed to and published in "Mechanics' Magazine." We are unable to give the name of the contributor, but he writes in encouragement of Perpetual Motion. The gist of his article is as follows:
We can now, however, soar above the clouds, explore the depths of the ocean, and skim over its surface. * * * And be it remembered that we owe these and many other advantages to a few persevering individuals who were, in all probability, stigmatized as chimerical visionaries by those who seem to have an unconquerable propensity to condemn everything above the level of their own understanding.
If by perpetual motion nothing more is meant than the putting in motion some of the most durable substances with which we are acquainted, in such a manner as to ensure a continuance of motion as long as those substances will resist the effects of time and friction, I do not despair of seeing it accomplished. * * * [He thinks there is] reasonable ground to hope that the time is not far distant when even this impossibility must yield to persevering ingenuity. In the present state of public opinion with regard to its practicability, it would be looked upon as an empty boast, were I to assert that the discovery is already made.
T. H. Pasley
T. H. Pasley in 1824, contributed an article to "Mechanics' Magazine," asserting the possibility of Perpetual Motion. The following excerpts give the substance of his article:
I feel no hesitation in standing up in support of this grand desideratum,—this almost forsaken friend of science,—whether the thing be practicable or not.
On the contrary, "Persevere" should be every one's advice; to do so, or discontinue, every one's own pleasure. And why should the impossibility of anything be pronounced unless it be established wherein the limits of possibility consist?
It is puerile in the extreme to be foretelling defeat when so many other objects may be gained by the highly laudable pursuit, perhaps of greater advantage to society at large than the discovery in question. * * * In a word, were the perpetual motion discovered tomorrow, it would be wise of all the governments of the world to offer a very high reward for some species of discovery that would be universally sought after, although it might never be found out. * * * The effects of industry are—enlargement of the mind, accumulation of knowledge, and rendering ourselves ignorant of the torments which idleness and dulness always engender. * * * In the next place, there are no solid grounds for the assertion that the discovery of a perpetual motion is an impossibility. In the present state of human knowledge respecting the powers of nature, it is not demonstrable one way or another. * * * The study of what relates to the perpetual motion has this great advantage, that it directs to the discovery of error as well as of truth; whereas, what are they which are called truths of science at present but vacillating human opinions, or erroneous assumptions of what we call natural causes? What are they but such as consist in mere assumption, sanctioned by time, and admitted by existing authorities in science, and of course generally acquiesced in, without previous investigation?
So far, then, from being guided in our decision respecting what is possible by the "unerring laws of nature," by "mathematical demonstration," and by "experimental proofs," we are continually misled by an erroneous faith in the nonentity, attraction.
On such an imperfect knowledge of the causes of phenomena, who should say he knows what can or what cannot be discovered?