J. W. Peck

“ For if the corpuscles collide with each other between two material bodies, no attraction effect will be produced ; just as in an ordinary gas there is equality of pressure on all sides of an immersed body despite the presence of other bodies. If however we could immerse in an ordinary gas, two bodies sufficiently small, and at a less distance from each other than the free path of the particles of the gas, then there would be a shielding effect and a tendency to come together. ”

“ Then within that range we have the equal distribution of the streams in all directions, as in Lesage's theory, but instead of the mysterious agency at the boundary propelling the streams of corpuscles, we have the ordinary dynamical action of the larger quantity of gas. The gas as a whole is in stationary motion, but in small regions — the solar system for example — the motion is that of the Lesage theory. On this view, gravity does not act between two bodies at distances greater than the free path, and hence, as Preston points out, a greater stability is given to the universe. ”

“ From what we have described, it is evident that the amount of shielding and consequently the attraction is, as regards bodies of different sizes, proportional to the surfaces and not to the masses. For if a body is conceived as stopping at its surface all the corpuscles which strike it, then the amount of matter inside the body has no effect on the action. This difficulty Lesage evades by a hypothesis, which may at first sight seem rather arbitrary, but which is really justified by many other phenomena in the range of Physics and Chemistry. ”

“ This body will be beaten upon by the torrent of corpuscles on all sides. Bearing in mind that the corpuscles are very small in comparison with the particles of gross matter, that the impacts follow upon each other with extreme rapidity, that the mean velocity of each stream is the same, that the mean density (i.e., the number of particles per unit length) of each stream is the same, we see that there will be no resultant tendency to move the body in any direction. That discrete impacts can produce the effect of a continuous pressure is an accredited fact of the kinetic theory of gases. ”

“ If we revert for the moment to the old [29] emission theory of light, the analogy becomes complete. In these days when ionic theories are being developed, and radio-active bodies experimented upon, it is as well not to be over contemptuous towards suppositions involving corpuscles and emissions of particles.
"Empty space " is thus to be regarded as a vast storehouse of energy full of minute corpuscles, moving in straight lines with high speeds in all possible directions. ”

“ When the distance between the attracting bodies becomes comparable with [22] their dimensions, so that they can no longer be regarded as practically at a point, the supposition is made that between every particle of the one and every particle of the other there is an action in the straight line joining the particles. The results which mathematical theory builds on this supposition are perfectly concordant with experience. ”

“ Absence of reflection, refraction, retardation, shielding or other disturbance of the action. In all the other natural actions, which are conveyed through space from one body to another, there is a marked effect produced by varying the nature of the matter in the intervening space. Light is reflected, refracted, polarised. Sound is reflected, absorbed, retarded. Electric and magnetic actions are influenced by the nature of the medium, in ways too numerous to mention. The radiations from radioactive bodies are capable of being deflected or absorbed. ”

“ Gravitation seems therefore, to have no tangible relation to the physical or chemical condition of the acting masses or of the intervening medium.
10) Duality of the action. The mathematical theory of attraction employs the fiction of a single body creating a field of force round it, but this idea though convenient for analysis has no physical counterpart. The action is essentially a dual one requiring the presence of two bodies ; and to the attraction on the one there always corresponds ( in accordance with Newton's Third Law of Motion,) the counter and equal attraction on the other. ”

“ For, as we have seen, we require a large number of corpuscles impinging in quick succession to give the effect of continuous pressure ; we require a high speed to give absence of resistance to the motion of ordinary matter and to give static attraction, the same value as kinetic ; and we need small dimensions to give impalpability, while at the same time, in virtue of the high velocity, the momentum and energy remain normal. ”

“ But when, as in the case of the corpuscles according to Isenkrahe, the colliding bodies are structureless, there can be no such transformation. Complete elasticity is necessary in any ultimate bodies.
We have thus traced the development of the corpuscular hypothesis from its first enunciation down to the form into which modern scientific speculation has moulded it. ”

“ The necessary condition is that the impacts shall follow each other sufficiently rapidly. We have, in fact, a complete analogy in the pressure produced on the surface of a solid sphere immersed in a gas. ”

“ But if the effects of gravity are to be produced, the corpuscles must rebound after impact on gross matter with less linear momentum than before; for otherwise the whole effect of the shielding would be done away with, and the rebounding particles would kinetically replace those which had been diverted. Hence a diminished velocity is necessary for all those corpuscules which have just suffered collision with gross matter. What then becomes of the energy so disappearing ? ”

“ Hence also the supply of energy does not come from and go to regions inaccessible to thought, but is self-contained in the fluid, like that of a gas in a closed vessel ; and furthermore, all the energy has an understood reason for its existence, in that it is needed to maintain the uniformity of state.
We have now to notice a very important qualification, viz. : — that the free path of the corpuscles (i.e., the distance between two successive collisions of corpuscle with corpuscle) must be great ”

“ The third points to the fact, that the ether, instead of being the passive vehicle of energy, would be, on this theory, a hugely charged storehouse, abounding in energy in every part ; while the gross matter for whose service, this energy exists, occupies only an inconsiderable part of the region. ”

“ We have already dealt fully with the most important points, the law of masses and the law of distances (3) and (5) . It may be noted in regard to the latter, that Jarolimek's objection to Preston's result is not fatal ; for we have only to take a lower value of the free path than the mean, to correspond to the known range of gravitation. As to (1) radial nature of the action; (7) undiminished intensity in time, and (10) duality of the action — the mechanism explains these conditions completely. ”

“ The Hertzian waves and, to a less extent, the Rontgen rays are under our control in the medium. Gravitational action, alone, exists between the two bodies and cannot be affected by any known treatment of the intervening space. Only at the gravitating bodies themselves have we any control over this agency. ”

“ AMONG the problems which Nature presents, there is none more fascinating and none more baffling than that which relates to the mechanism of gravitational attraction. Natural Philosophy deals with many recondite subjects ”

“ In fact the three dimensional nature of space, here conditions the exact index 2. The area of the surface of a sphere is proportion al to [30] the square of the radius, and hence for any radiation from a point the action per unit area is inversely proportional to the square of the distance from the source. If we look at the figure, we see this matter illustrated for the corpuscles. Suppose A and B to be the two bodies which are producing mutual shielding from the impinging torrents. ”

“ The change into rotational energy might not always be possible, but that into vibrational energy is always possible, provided the corpuscle be not the hard atom of Lesage, but a body possessing internal structure, and capable of modes of vibration. ”

“ Yet speculation often rushed in where science feared to tread. Elastic media exerting stress, fluids of variable density, transmitting pressure, streams of particles acting by impacts, impalpable ethers conveying waves, these and many other types of action have been put forward. In the i8th century, we do not find very many theories, because the tendency during that period was, for the reasons we have seen, to give over gravity to the abstract mathematicians, and to regard action at a distance as the outpost, beyond which enquiry need not be pushed. ”

“ Jarolimek considers the effect of this varying length of free path upon the attraction of two bodies. Only those corpuscles can be effective, which have a free path in excess of the distance between the bodies : all others produce no attractive tendency. ”

“ There is a great difference between the 10-20 of our illustration and the infinitely small which defies thought. The visible spectrum contains an octave of vibrations as real, as distinguishable, as capable of analysis as an octave of notes in the human voice. ”

“ The law of masses may be extended to as great masses as those for which observation proves it (for example the mass of Jupiter) , by making the diameters of the bars of the supposed cage atoms constituting heavy bodies, small enough. ”

“ Certain bodies present along different lines, different properties in regard to certain physical actions. Thus wood conducts heat . at one rate along the grain, at another across. Crystals allow light to travel at different speeds according to the position of the line chosen in reference to the axis of the crystal. ”

“ Institution, which summarises the state of the problem up to 1876, there are mentioned about twenty accredited men of science who have taken up the problem, and put forward hypotheses for its solution. ”