Chapter IX: Aether and Magnetism (2)

In other words, to put it plainly and tersely, each aetherial atmosphere revolves round the planet, subject to certain limitations, in the same way that the aerial atmosphere turns round with the earth, as that planet revolves on its axis. At first sight, such an assumption may seem impossible, but a little careful consideration will show not only the possibility of such a cause, but will establish it, as the only reasonable and philosophical explanation for the phenomena we are seeking to explain, viz. the electro-magnetism of all celestial bodies.

There is nothing extravagant in this assumption, as we already have a similar illustration in the case of the atmosphere which goes round with the earth as it revolves on its axis. We have only to extend the same principle a little further, viz. to the aetherial atmosphere, and we at once get the true physical conception of the hypothesis suggested to explain the magnetism of all celestial bodies. We have already learned that Maxwell has proved that the equations for moving magnetic bodies are the same as those for stationary bodies, from which we came to the conclusion that the electric and magnetic field of any planet goes with that planet as it revolves on its axis in its journey round the sun.

I would like to ask the reader to try to conceive of any electric or magnetic field traversing space in association with any planet or sun which is revolving on its axis, while that electric or magnetic field does not revolve either partially or wholly with the revolving body. The field can only be stationary relatively to the planet or sun, as it revolves with the planet or sun on its axis.

There may be, as there doubtless are, conditions governing that revolution, as is the case with the atmosphere moving and revolving with the planet, but it is an absolute impossibility for Maxwell's equations relating to moving magnetic bodies to be carried to their logical conclusion, without affirming some such hypothesis as we have affirmed in relation to the cause of all solar magnetism.

Let me at once point out, this solution has already been offered by one whose name has been referred to several times. I refer to Professor Challis. Let us see what he has to say as to the cause of the earth's magnetism. In dealing with this subject, and writing in the _Phil. Mag._, 1872, par. 42, he states: "With respect to all magnetism which has a cosmical origin, the view I now take is that it is due to gyrations of the Aether, produced by the impulses which it receives from the motions of the constituent atoms of the bodies of the solar system. The gyrations may either be immediately generated by the rotations of the bodies about their axes, or directly result from disturbances of the Aether caused by their motions of translation. This impressed motion will be converted into circulatory or gyratory motion. Such circulatory motion will necessarily partake of the motion of translation of the bodies which generate them, so as to have always the same geometrical relation to these bodies provided their motion be uniform."

In paragraph 46 he continues: "From what has been already argued (42), the motions impressed on the Aether by the earth in consequence of its rotatory or orbital motions result in circulating motions which would be steady motions, having always the same geometrical relation to the position of the earth's centre."

Again, Ampère and Faraday were also of the opinion that the magnetism of the earth was due to the circulation of electric currents round it, for in par. 446, _Exp. Res._, Faraday states: "Assuming with Ampère that the magnetism of the earth is due to electric currents circulating round it, parallel to the equator."

I think it will be seen from these extracts that the hypothesis suggested for all planetary and stellar magnetic bodies is thus confirmed by Professor Challis, and by Faraday and Ampère. Professor Challis in these passages clearly and definitely points out that there are circulatory motions in the Aether, which motions are produced by the rotation of the earth or other body on its axis, and that these circular motions of the aetherial medium always maintain the same geometrical shape relative to the earth's centre. So that we have only to combine with his hypothesis the electro-magnetic basis of the Aether, and we at once get the circulating currents of electricity constantly flowing round the heavenly bodies, which produce and give rise to the permanent magnetism of those bodies.

If we desired still further confirmation as to the circulating motions of the Aether caused by a rotating body, we find it in the writings of Herschel, who in relation to this matter asks:[39] "What is the law of density of the resisting medium which surrounds the sun? Is it at rest or in motion? If the latter, in what direction does it move? Circularly round the sun, or traversing space? If circularly, in what plane? Supposing the neighbourhood of the sun to be filled with material fluid, it is not conceivable that the circulation of the planets in it for ages should not have impressed upon it some degree of rotation in their own direction, and this may preserve them from the extreme effects of accumulated resistance!" Words like these from one of the most searching intellects of the last century are well worthy of our consideration, and the suggested effect on the Aether caused by the continued rotation of the earth gives us the key not only to the problem of celestial magnetism, but also to the other outstanding scientific problems.

For example, there is the problem of the relation of moving matter to the Aether around it which still remains unsolved. The physical cause of the rotation of the earth, and all other celestial bodies upon their axes, with unceasing regularity, still remains to be discovered. The physical explanation as to the reason why the earth moves round the sun in its orbit according to Kepler's Laws, has yet to be determined, and, lastly, there is the relation of the magnetic vibration to the electric vibration in connection with the electro-magnetic theory of light still to be solved.

Now, presuming that all these can be solved by the philosophical hypothesis, that the electro-magnetic Aether circulates round each planet and sun and star, that revolves in space, then we are justified in our conclusion that such is the true cause of all electro-magnetism that exists in connection with planetary and stellar bodies. I venture to premise that all these problems can be solved by the simple solution here given, and will prove that this solution adequately accounts for all the other phenomena referred to.

Before proceeding to do this, we will endeavour to prove this hypothesis by an altogether different method of reasoning, in order to confirm the statements made in this article. Let us therefore endeavour to form a complete view of the physical state of the solar system, and for the sake of simplicity we will suppose it to be at rest in space. We shall deal with the effect of its motion upon its own planetary system, when we explain Kepler's Laws.

We have, therefore, the Sun in the centre (see Fig. 14) of the system, with Mercury, Venus, the Earth, Mars, Jupiter, Saturn, Uranus, and Neptune revolving round the sun at their respective distances, which are subject to variations owing to certain causes which can be satisfactorily explained. But circulating round the sun, in the same direction as the rotation of the sun on its axis, we have the electro-magnetic Aether, with its wide-spreading flow and extensive electro-magnetic field. In like manner, we have each planet with its aetherial electro-magnetic field, which also circulates round each planet in the same direction as the planet revolves, that is, from west to east, and in the same direction as the sun's electro-magnetic field revolves.

Thus we have to picture the whole of the solar system in a state of regular and harmonious rotation, while each planet adds to the harmony of the rotation by itself rotating in its own aetherial electro-magnetic field, while all rotate in the same direction, viz. from west to east.

Of course there are several objections that can be raised to such a hypothesis, and those objections will be briefly dealt with in a subsequent article, but I venture to think that this hypothesis is the true philosophical explanation of a problem which has formed one of the greatest outstanding difficulties in regard to the Aether medium for many years, that problem being the relative motion of the Aether and Matter. Lord Kelvin, in an article in the _Phil. Mag._ for July 1901, entitled "Clouds over the Dynamical Theory of Light," refers to this very difficulty, and states there are two clouds over the present undulatory theory of light, one of which has reference to the difficulty of conceiving a body like the earth or any planet rushing through the Aether without subjecting the Aether to enormous laceration, and concludes by saying that "we must still regard this cloud as very dense." Here, then, is the key to the solution of the problem.

The earth does not rush through the Aether, but the Aether being gravitative, it is associated with and bound to each planet, and accompanies that planet in its journey though space, rotating with it in the same way that the atmosphere does, as we shall prove later on.

This conception is fully in accord with our hypothesis as to the physical explanation of the cause of the electro-magnetic character of all the heavenly bodies, and indeed is the only physical solution that can adequately account for all the varied phenomena hitherto unexplained in connection with the celestial mechanism.

From the foregoing statements, we are now in a position to consider the term Electro-Kinetic Energy, as used by Clerk Maxwell. What does he mean by Electro-Kinetic Energy? Let us see what he has to say about the term himself.

In par. 636 of his _Magnetism and Electricity_ he writes: "According to our hypothesis we assume kinetic energy to exist wherever there is magnetic force, that is, in general, in every part of the field. This energy exists, therefore, in some kind of motion of the matter in every portion of space;" while again, in par. 569, he states: "The electric current cannot be conceived except as a kinetic phenomenon." Even Faraday speaks of the electric current as "something progressive, and not a mere arrangement" (_Exp. Res._ 283).

Then again in par. 552 he writes: "It appears, therefore, that a system containing an electric current is a seat of energy of some kind, and, since we can form no conception of an electric current except as a kinetic phenomenon, its energy must be kinetic energy, that is to say, the energy which a moving body has in virtue of its motion."

Here, therefore, according to Clerk Maxwell, the kinetic energy of an electro-magnetic field is nothing more or less than the energy which a moving body possesses in virtue of its motion. Any other explanation of kinetic energy would be opposed to all the Rules of Philosophy; for experience in its widest form incontrovertibly proves that all kinetic energy is associated, and alone associated, with a moving body; therefore in all electro-magnetic fields there is this kinetic energy ever being manifested. We have, however, learned that the solar system forms a huge electro-magnetic field, traversed by lines of force, as Maxwell and Faraday suggested. Therefore, in the solar system, there must be this kinetic energy due to the motion of a moving body, which is the electro-magnetic Aether.

We have, however, just arrived at the conclusion that in the solar system there is ever going on a circulatory or rotatory movement of the electro-magnetic Aether forming currents around each electro-magnet. On the hypothesis of an atomic and gravitating Aether we have, therefore, a medium or body continually circulating, which medium possesses inertia and momentum, and it is philosophically possible for such a rotating medium to possess kinetic energy. So that our explanation of this term, as used by Clerk Maxwell, is, that this kinetic energy is indeed due to the momentum of the moving Aether. Such a hypothesis is strictly philosophical, and literally fulfils the statements made by Clerk Maxwell himself in the paragraphs already referred to.

A remarkable feature about this hypothesis lies in the fact, that it is the very hypothesis that Von Helmholtz suggested as the explanation of the term. He came to the conclusion that the kinetic energy was due to the momentum of the moving Aether. But with a frictionless Aether such a hypothesis, although correct, was philosophically untenable. In view of the theory of the Aether presented in this work, however, both Clerk Maxwell's and Von Helmholtz's statements find their literal and perfect fulfilment. So that in an atomic Aether, which is gravitative because atomic, and rotatory because it is gravitative, combined with its electro-magnetic basis as proved by Hertz, we find for the first time a correct philosophical explanation of one of the most puzzling terms used by Maxwell in his greatest work on _Magnetism and Electricity_. This solution alone ought to stamp the theory of an atomic and gravitating electro-magnetic Aether with that authority that is always associated with the names of two such great thinkers and experimentalists as those just mentioned.

The fact that the Aether is held bound to a planet has already been suggested by Sir G. Stokes to account for the aberration of light already referred to. In the _Phil. Mag._, July 1845, he writes: "I shall suppose that the earth and the planets carry a portion of Aether along with them, so that the Aether close to the surface is at rest relatively to the earth, while its velocity alters as we recede from its surface, till at no great distance it is at rest in space." Sir G. Stokes does not, however, say how the Aether is held bound to the earth, and apart from an Aether which is gravitative, no satisfactory explanation can be given. Further, it is noticeable, that he suggests that the other planets also carry part of the Aether associated with them along with each planet as it pursues its journey. It would be distinctly unphilosophical to assume that the earth was the only planet that carried its aetherial field with it. So that by following Sir G. Stokes' suggestion, we practically arrive at the same conclusion in relation to the motions of the Aether that we have already arrived at from magnetic phenomena.

With this view of the case we are now in a position to answer a question asked by Professor Schuster at the British Association in 1892. He asked, "Is not every large rotating mass a magnet?" and added, "If it is, the sun must be a powerful magnet. The comets' tails, which eclipse observations show stretching out from the sun in all directions, probably consist of electric discharges." Now, in relation to this question, the answer is that every rotating body in the Aether is undoubtedly an electro-magnet. Thus, not only is the sun an electro-magnet, but every planet and satellite, and every meteor that rotates in the electro-magnetic Aether, is converted into a magnet, partly by that rotation, and partly by the currents induced in the Aether by that rotation. We shall also find when we come to deal with the phenomena of comets' tails, that Professor Schuster is also right as to their cause, and that they are due to electro-magnetic repulsions originated in the Aether by the sun, which is an electro-magnet.

[Footnote 39: _Outlines of Astronomy_, Herschel.]

ART. 92. _Cause of Rotation of the Earth on its Axis._--If there is one fact true in relation to the earth as a planet, it is that the earth rotates on its axis every 24 hours. Day in and day out, for centuries past, this revolution has taken place as the earth journeys in its annual path round the sun.

Not only does the earth rotate on its axis, but every other planet rotates on its axis in varying times, as the following table shows--

HRS. MIN. SEC.

Mercury 24 5 0
Venus 23 24 0
The Earth 23 56 4
Mars 24 37 23
Jupiter 9 55 0
Sarturn 10 14 23
Uranus ?
Neptune ?

Further, the sun also rotates on its axis in a period of 26 days. Here, then, are certain phenomena in connection with the solar system, for which up to the present no explanation as to the physical cause of rotation has ever been offered. Surely there is some physical cause, to account for such a rotation, and if there be a physical cause, then the problem to be solved is--find the physical cause to account for the continuous and ever-recurring rotation of all the planets and the sun on their axes, which shall be so effective and continual that, year in and year out, the rotation of all the planets may be continued as observed. In solving this problem we have to revert to our reason why the earth is a magnet. In Art. 91 we learned that the earth and all the other planets, and indeed all stellar bodies, were electro-magnets, because the electro-magnetic Aether was constantly circulating round them.

If, by accepting this explanation, we can at the same time solve the problem of the rotation of the planets, and the sun, on their axes, then we shall have further evidence that our hypothesis is the correct one. Now let me ask, What is the effect of an electric current continually circulating round any magnet in the same way that the electro-magnetic Aether continually circulates round the earth, which is a magnet?

To find out what the effect is, we must resort to experiment. Professor Lodge, in his _Modern Views of Electricity_, shows us the effect of any circulating current of electricity revolving round a magnet. In his chapter on Electro-Magnetism he writes as follows: "How does a current act on a magnetic pole? Two currents attract or repel each other, two poles attract or repel each other, but a current and a pole exert a mutual force which is neither attraction nor repulsion. It is a rotatory force. They tend neither to approach nor to recede, they tend to revolve round each other." "A singular action this and at first sight unique" (p. 135). "The two things will revolve round each other for ever. This affords and has afforded a fine field for the perpetual motionist, and if only the current would maintain itself without a sustaining power, perpetual motion in fact would be attained."

Faraday has shown by experiment the action of a current on the magnet, and _vice versâ_. Faraday, in his description of an electro-magnetic apparatus for the exhibition of rotatory motion, shows how the rotation of a current round a magnet, and a magnet round a current, may be experimentally proved. With the apparatus used he shows that the current of electricity may be made to revolve round the pole of the magnet in the direction dependent on the pole used, and further, illustrates how the magnet may be made to revolve round the current. (Plate 4, Fig. 5, _Exp. Res._)

Thus we learn that wherever we have a current constantly circulating round a magnet, there we have the conditions by which, according to Professor Lodge, perpetual motion may be obtained, that is to say, the two will revolve round each other as long as the current is maintained. Here then we find in space those very conditions by which perpetual motion may be obtained.

We find the electro-magnetic Aether constantly circulating round the planetary magnets, with the result that not only will the current continue to revolve around the planet, but the planet will continue to revolve upon its axis as it revolves round the current. In fact we get in space an example of perpetual motion. We know that the rotation of the earth on its axis has been in existence for several thousand years, and therefore we have a right to assume that it revolved on its axis through the untold ages of past geological times as revealed by the strata, and rocks of pre-historic ages. Thus the motion must have continued, so far as the earth is concerned, at least 100,000,000 years, accepting that period as the age of the earth, but no physical reason so far as I know has ever been assigned for such continued rotation.

If, therefore, it be true that the joint action of a current and a magnet is a rotatory one, then, seeing that in all planetary and stellar space we have both these conditions of matter, that is, the electro-magnetic aetherial current, constantly circulating round an electro-magnet, we have, in space, the conditions by which perpetual rotation may be maintained. We have therefore presented to us in that joint action, the true cause of the continued rotation of the earth on its axis, and therefore of all the planets on their axes, together with the sun on its axis; and, if we carry the principle into the stellar world, we can philosophically come to the conclusion that the same conditions prevail there that prevail in the solar system, with the result that we have now a physical cause which fully satisfies all Rules of Philosophy to account for certain phenomena which up to the present have never yet been accounted for from the physical standpoint. Thus in solving the problem of the earth's rotation on its axis, we find greater confirmation in the view presented in a previous article as to the circulating motion of the electro-magnetic Aether around any and every body in space. We shall deal again with the relation of a current and a magnet, when we come to the physical explanation of Kepler's Laws.

ART. 93. _Vortex Motion._--From Art. 91 we have seen that the electro-magnetic Aether possesses a circulating or rotatory motion around each central body, and because of this rotatory motion, the body is at once converted into a magnet. We have also seen that Professor Challis believed in the circulatory or rotatory motion of the Aether, as also did Ampère.

Thus we are led back by scientific experiment and philosophical reasoning to the conception of vortex motion with which the world was familiar in the days of Kepler, Descartes, Huyghens and Bernoulli. There is this difference, however, that whereas the vortex motion of those philosophers was to displace and do away with Gravitation, the circulatory or rotatory Aether suggested by electro-magnetic phenomena is to supplement, confirm and establish more firmly than ever the true powers and laws of Gravitation Attraction.

Before passing, it will be as well to briefly glance at the conception of vortex motion as suggested by Kepler and Descartes and others. Whewell on this matter in his _Inductive Sciences_ states that "Kepler assumed that a certain force or virtue resided in the sun by which all bodies within his influence were carried round him. He illustrated the nature of the force in various ways, comparing it to light, and to the magnetic power which it resembles in the circumstances of operating at a distance, and also of exercising a feebler influence as the distance increases." "Another image to which he referred suggested a much more conceivable kind of mechanical action by which the celestial motions might be produced, viz. a current of fluid matter circulating round the sun, and carrying the planets with it like a boat in a stream." Whewell adds: "A Vortex fluid constantly whirling round the sun, kept in this whirling motion by the sun itself, and carrying the planets round the sun by its revolution, as a whirlpool carries straws, could be readily understood, and though it appears to have been held by Kepler that this current and Vortex were immaterial, he ascribes to it the power of overcoming the inertia of bodies, and of putting them and keeping them in motion."

Now, as we have seen, the electro-magnetic Aether is not immaterial but material, as it is matter possessing mass and inertia, the same as any other matter, as Tyndall and Lord Kelvin stated (Chap. IV.). Thus the objection to Kepler's immaterial vortices is met and overcome by our conception of the Aether (Chap. IV.). Descartes, as Whewell points out, asserted, "that a vacuum in any part of the universe is impossible. The whole universe must be filled with matter, which must be divided into equal angular parts. This matter being in motion, the parts are necessarily grounded into a spherical form, and the corners thus rubbed off, forming a second or subtle matter. There is besides a third kind of matter, of parts more coarse and less fitted for motion. The first part makes the luminous bodies as sun and stars, the second part is the transparent substance of the skies, and the third part is the material of opaque bodies as the earth, planets and comets. We may suppose that the motion of these parts takes the form of revolving circular currents or vortices. By this means the first matter will be collected to the centre of each vortex, while the second or subtle matter surrounds it, and by its centrifugal effect constitutes light. The planets are carried round the sun by the motion of the vortex, each planet being at such distance from the sun as to be in a part of the vortex suitable to its solidity and mobility. The satellites are in like manner carried round their ordinary planets by subordinate vortices."

It would almost seem from this quotation that we had adopted purely and simply Descartes' and Kepler's ideas _in toto_, whereas the truth is that the hypothesis of a rotating electro-magnetic Aether has been arrived at by following Newton's own Rules of Philosophy, and by discarding everything not in harmony with experience and experiment.

Further, Descartes was unable to give, or explain the ellipticity of the orbits of planets, and had to assume that there were elliptic vortices. When we come to deal with Kepler's Laws, and their physical interpretation, the correct solution of this problem will be given from a purely experimental and philosophical standpoint, and in a way and manner never suggested by Descartes or any other believer in the theory of vortices as then known and understood. Indeed there is no objection to the theory of vortices, which cannot be satisfactorily explained by a rotating electro-magnetic Aether, as we shall see when we deal with Newton's Laws of Motion and Kepler's Laws.

Both Liebnitz and Huyghens were believers in the theory of vortices, and the fact that Huyghens' undulatory theory of light stands to-day as an accepted theory, is conclusive evidence that he was a philosopher of the highest order, and his adhesion to the theory of vortices proves that he was convinced that there was some truth in it.

It is a result greatly to be desired, therefore, if it can be demonstrated, that in the Aether there is this rotatory motion continually going on around every planet, satellite, sun or star; because it will then join together, in perfect harmony, two great theories in relation to celestial phenomena, that contended with each other for supremacy for very many years.

It will prove that, after all, men like Kepler, Descartes, Huyghens, and Bernoulli had caught glimpses of the great truth which was partly revealed by celestial phenomena, and that it was only for lack of data that they were unable to successfully compete with Newton's mathematical genius, by which he was able to bring his Law of Gravitation safely through the conflict with the simpler conception of aetherial vortex motion. Of course certain objections will have to be met and answered before this aspect of aetherial dynamics can be expected to supplant the more cumbrous and somewhat intricate mathematical laws of motion, but I shall prove later on, that all these objections can be answered from a satisfactory standpoint.

So that if a modified form of aetherial vortex motion can be successfully demonstrated to exist in the electro-magnetic Aether, then we shall see the conflict that waged about two hundred years ago, brought to a satisfactory issue, in the union of the two greatest philosophic theories for the explanation of celestial phenomena that the world has ever seen.

From that union, therefore, there will then emerge a truer, simpler, and yet grander conception of the motions of the universe, which, when perfected by abler minds, will be as perfect a theory as human intelligence and philosophy can make it. So that, what an atomic and gravitative Aether has done for Newton's corpuscular theory of light, in showing that it can be united and combined with the undulatory theory, and by such combination, for the first time, such phenomena as the transverse action of light can be probably demonstrated and explained, together with other phenomena relating to reflection and refraction of light, the enlarged conception of a rotating electro-magnetic Aether will do for the two great theories that vied with each other for supremacy for so many years. Thus it will be shown that the philosophers like Kepler, Descartes, and Huyghens, the former of whom has stamped his name on the three laws that bear his name to-day, and the latter who gave us the inception of the very theory that overthrew Newton's theory of light, had after all a more or less true philosophic conception of the physical mechanism of the solar system and of the universe at large.

ART. 94. _Relative Motion of Aether and Matter._--There is hardly any subject of greater importance which is engaging the attention of scientists at the present time, than the question as to what is the relative motion of Matter to the Aether in which it moves.

I venture to premise the successful solution of the problem will be accompanied with the greatest advance to science that has been known for a long time. The problem to be solved may be stated thus: "Does the Aether surrounding a planet or sun or any body in space move with that body, or does it allow the body to pass through it?"

Up to the present, opinions on the subject have been varied and conflicting. Some scientists hold that the planetary and other bodies in space pass through the Aether without disturbing it, while others hold that part of the Aether is carried along by the moving planet. Fresnel assumed that the surrounding Aether was carried along by the earth, so that all relative phenomena would be the same as if the earth were at rest. Fizeau, from experiments which he conducted on running water, also came to the same conclusion.

With the old idea of a frictionless medium, some of the present accepted theories are altogether untenable, because, if Aether is frictionless, how can it be carried along with the moving body, unless it is held bound to that body? and how can it be held bound to that body if it is frictionless?

The whole view of the Aether is, however, changed by the conception of the Aether put forward in Chapter IV. Aether is Matter, and being matter it is also gravitative, and therefore is just as much subject to the Law of Gravitation as any other kind of matter, as Young stated in his Fourth Hypothesis (Art. 45).

We will therefore attack the problem of the relative motion of the earth and the Aether around it from this new standpoint. In order to be strictly philosophical, we must base our hypothesis and conception on experience and observation. Where in the whole of planetary phenomena do we find similar conditions which exist between the Aether and the earth? Such conditions are alone to be found between the atmosphere and the earth. The analogy between the atmosphere and the earth, and the Aether and the earth is very striking, as the following comparisons will prove.

The atmosphere (when pure) is invisible, so is the Aether. The atmosphere is atomic, the Aether is also atomic. Both are subject to the same laws of elasticity and density, and both are gravitative, according to our conception of the Aether. Now what is the effect of any large revolving body on a liquid or gaseous medium surrounding that revolving body?

If experience is any guide, we learn that the motion of the revolving body is either partially or entirely transmitted to the liquid or gaseous medium surrounding such a body. So far as our experience teaches us anything, it teaches us that to that rule there is no exception, and no experiment can be devised of any body revolving in water or a gaseous medium as air, without that body imparting its rotation to the water or the air. The atmosphere in relation to the earth is no exception to this rule. We know that the earth has an equatorial circumference of about 24,000 miles, and that it revolves on its axis once every day, so that at the equator the surface of the earth is whirling round in space at the rate of 1000 miles per hour.

Try to conceive what the result would be if the atmosphere were stationary at the earth's surface in the equatorial regions. It would mean that any body on its surface would be whirled round at that rate, while the atmosphere, being stationary, would exert a power equal to a wind travelling at the rate of 1000 miles per hour.

Under the influence of such a hurricane, nothing could exist on the surface of the earth at the equator, if the earth revolved on its axis and the atmosphere did not participate in that motion. But the atmosphere is gravitative, and being gravitative, it is not only held bound to the earth as it revolves on its axis in its onward rush through space, but accepts the revolving motion of the earth, with the result that as the earth revolves on its axis, the atmosphere revolves also.

Thus a balloon at the equator if allowed to rise several hundred feet above the surface could remain comparatively stationary if held by a rope to overcome its tendency to rise, whereas such an event would be impossible if the atmosphere failed to receive only half of the motion of the earth's surface, as it would still have a power equal to that of a wind blowing at the rate of 500 miles an hour. If, however, we come further north, or go further south, then we find that the surface of the earth does not have the same velocity as at the equator, with the result that the atmosphere has not the same velocity either; consequently it would travel slower in the temperate regions than in the equatorial regions, and slower still at the poles than in the temperate regions.

We know by experiment what the effect of increased velocity has upon any whirling body; it tends to enlarge the body at those parts where the velocity is the greatest, the consequence being that the bulging out of the atmosphere would be greatest at the equator. We find a similar result in the shape of the earth, where the equatorial diameter is greater than the polar diameter, because of the centrifugal force being greatest in the equatorial regions.

We have, therefore, to apply these facts to the aetherial medium which surrounds all planetary and stellar bodies in the same way as the atmosphere does; and which, being also gravitative, is equally subject to the same laws of motion. We have seen, therefore, that not only does the earth revolve on its axis, but that the atmosphere revolves on its axis also, and that the velocity of its revolution is greatest in the equatorial regions, the atmosphere spreading or bulging out in those parts more than in any other part of the earth's surface.

Let us suppose that the atmosphere extends 200 miles above the earth, and that there we come to the pure Aether of universal space. In view of the fact that Aether is Matter, and therefore gravitative, it is reasonable and logical to conclude that exactly the same result follows in relation to the atmosphere and the Aether at that height, as follows in relation to the earth and the atmosphere 200 miles beneath.

Unless this view is accepted, we should then have our second Rule of Philosophy violated, as we should have matter revolving in more rarefied matter, and failing to impress upon that rarefied condition of matter the motion either partially or wholly which it itself possesses; and such a result being contradictory to all experience cannot be admitted from a philosophical standpoint.

Therefore, the only solution is, that the rotating atmosphere imparts some of its motion to the aetherial atmosphere, which in its turn rotates, and that that rotation is governed by exactly the same conditions as govern the relation that exists between the earth and the atmosphere. Therefore the Aether in space associated with each planet or satellite or sun or star, rotates with the rotating body, and that rotation imparts to the Aether a greater bulging out in the equatorial regions of the aetherial atmosphere than in any other part thereof. It is interesting in relation to this point to note Herschel's view of the effect of the rotation of any body upon the Aether. In his _Outlines of Astronomy_, in a note, p. 358, he states: "Supposing the neighbourhood of the sun to be filled with a material fluid; it is not conceivable that the circulation of planets in it for ages should not have impressed upon it some degree of rotation in their own direction, and this may preserve them from the effects of accumulated resistance."

In this way we arrive at the conception of the motions of the Aether suggested by Prof. Challis from the magnetic character of the earth, which he thought were due to aetherial currents circulating around it, and we learn that such physical conception of the Aether fully agrees with the explanation of celestial bodies being electro-magnets; because, we have only to add to our rotating Aether that which it has been proved to possess, viz. an electro-magnetic basis, and we have at once the currents of electricity circulating round the earth and other planetary or solar bodies, by which is obtained the true explanation of the permanent magnetism of all celestial bodies.

Now to some minds unconversant with scientific research and knowledge, such a supposition may seem to be incredible, but that incredibility may disappear, when I say that the fact that the Aether is bound to the earth, and goes along through space with it, has actually been proved by some of the most delicate and successful experiments that have been made in recent times: experiments of which Lord Kelvin has stated that he can find no error or flaw in them. I refer to the scientific experiments of Michelson and Morley of America. For full particulars of these experiments I must refer the reader to the _American Journal of Science_, 1886, vol. 31, or to the _Phil. Mag._, vol. 44.

The conclusion which is arrived at from their experiments is, that the Aether is carried along with the earth as it rushes on its journey through space. Of course such a result is altogether opposed to the ordinary conception of a frictionless medium, and indeed to any conception of the Aether except to that submitted in this work, which is also in harmony with Young's Fourth Hypothesis (Art. 45).

So that Michelson's and Morley's experiment is a direct experimental demonstration of the fact that Aether is gravitative, and because it is gravitative, it is carried along with the earth, as that planet journeys through space. It further conclusively proves that not only is the Aether carried along with the earth, but that the Aether circulates round the earth in the same way that the atmosphere circulates round the earth.

This result naturally follows from the experiment, because, if it were carried along by the earth and yet did not rotate with the atmosphere, then we should have a result opposed to all experience and experiment, as these teach us that when a body revolves in a medium which is held bound to that body by Gravitation, the medium so held bound participates in the rotation of the revolving body.

So that in Michelson's and Morley's experiment we have experimental evidence of the fact, already stated, that the Aether circulates round the earth, and therefore, in view of the electro-magnetic character of the Aether, this circulation results in the production of magnetism in all the planets, and other bodies around which it circulates.

Thus not only does the Aether circulate round the earth, but it also circulates around every other planet, and not only round every other planet, but equally so around every sun and star, as stated in Art. 91.

These results are perfectly consistent with philosophical reasoning, and any other result would be inconsistent with the analogies presented to us by the phenomena of the Aether in relation to our earth as ascertained by experiments made by the scientists referred to. Thus for the first time the experiment is brought into harmony with our Philosophy, which up to the present has not been the case, a result which at once stamps the experiment with that validity of truth and fact which will ultimately win for it universal acceptance and favour.

We are now in a position to answer some queries regarding the motions of the Aether asked by Herschel in his work on _Astronomy_, p. 345. These I give with the answers opposite.

QUERIES. | ANSWERS.
|
1. What is the law of density | The Law of Gravitation
of the resisting medium which | (Art. 45).
surrounds the sun? |
|
2. Is it at rest or in motion? | In motion.
|
3. If the latter, in what | Rotates round the sun.
direction does it move? |
|
4. Circularly round the sun | Both, as it circulates round
or traversing space? | the sun while that body
| traverses space.
|
5. If circularly, in what | The plane of the ecliptic.
plane? |

ART. 95. _Physical Explanation of the Vibration in the Electro-Magnetic Theory of Light._--In Art. 78 we learned that light was an electro-magnetic disturbance in the Aether which was propagated through the Aether, with a finite velocity; and from this we gathered that light waves were nothing more or less than electro-magnetic waves, which were radiated from the sun, out into the Aether on every side.

We were unable, however, at that time to give a definite physical conception of the aetherial vibrations, or of the relation of the various types of vibration to each other. Since, however, the development of the Aether from the electric and magnetic standpoint, which has led us up to the fact that the Aether possesses a circulating motion round the sun (Art. 91), the solution of the problem appears probable. I am of the opinion that the physical conception of the various vibrations to each other is now within the region of possibility, and in this article I wish to endeavour to give what seems to me to be a correct and philosophical explanation of this part of the electro-magnetic theory of light, the physical conception of which up to the present has not been generally understood.

The explanation may, or may not, be fully complete, but even if it be not perfectly correct, I am convinced that it will ultimately lead to a satisfactory physical explanation of this part of Maxwell's Theory of Light. In forming a conception as to the physical character of the vibrations in the electro-magnetic theory, we have to remember that there are three distinct vibrations, or motions, concerned in this theory.

1st. There is the direction of propagation.

2nd. There is the direction of the electric vibration which is
at right angles to the direction of propagation.

3rd. There is the direction of the magnetic vibration or
motion which is at right angles to both of the other two.

Now we have seen that the direction of propagation of any aetherial light ray, is that of a straight line from the sun corresponding to the radius vector (Art. 76). We have also seen that the front of a light wave is really that of a spherical shell (Art. 71).

We have also learned that the electric and the magnetic vibrations are in the wave front, so that these two vibrations, which are at right angles to each other, are to be found on the surface, so to speak, of each aetherial spherical shell, that surrounds the sun with ever-decreasing density, and ever-decreasing elasticity.

Let us try to picture the actual fact by an illustration. Let _S_ be the sun, with concentric spherical aetherial shells surrounding it (Fig. 22). Then _S_ _A_ and _S_ _C_ will be rays of light being radiated out from the sun, and the magnetic and electric vibrations have to be both at right angles to the line of propagation and in the wave front; the wave front being represented by the circular lines showing the section of the concentric shells running north and south.

Now how can we picture these two motions at right angles to each other, and yet both at right angles to the line of propagation? First, let us take three straight lines and see how this may be done (Fig. 23).

Let _A_ _B_, _A_ _S_ be two straight lines at right angles to each other, and _A_ _C_ another straight line at right angles to both. This can only be done by making _A_ _C_ perpendicular to the plane of the paper, and can be illustrated by supposing that it represents a pencil or pen placed upright on the paper, the point of the pencil being at point _A_. If this be done, then not only will _A_ _B_ and _A_ _C_ be at right angles to each other, but both will be at right angles to _A_ _S_, which corresponds to the line of propagation.

Now refer to Fig. 22, and we shall see that the line _A_ _B_ and the boundary of the shell will practically correspond. So that any section of a spherical wave front will always be at right angles to the ray of light. But we have learned from Art. 89 that these sections of the aetherial spherical shell are really identical with Faraday's Lines of Force, with the result that along any line which stretches from the North pole of the sun to the South pole, there will ever be an electric vibration, which is put into motion by the elasticity of the aetherial vortex atoms. So that on every side of the sun there is ever going on this electric vibration, along the lines of force which correspond to a section of the aetherial shell, the surface of which really constitutes the wave front.

Therefore it can readily be seen, that, as these lines are at right angles to the propagation of the ray of light, the electric vibration is at right angles to the lines of propagation, and is thus in accordance with the result demanded by Maxwell's theory.

We have now to give a physical conception of the magnetic vibration or motion of the Aether, and this has to be at right angles to both the electric vibration and the line of propagation.

In Art. 91 we have learned that the Aether possesses a rotatory motion, by which it rotates round the central body of the solar system, the sun. So that if we take any point, for example, in the path of the ray as _S_{1}, _S_{2}, _S_{3}, and _S_{4}, situated upon some definite equipotential surface or lines of force, and if we will imagine those lines to rotate round the sun, as the sun rotates on its axis, then in time the points will have described half the circle, and will come to the position on the right of the sun indicated by the same Nos. _S_{1}, _S_{2}, _S_{3}, _S_{4}. Thus there has been an aetherial motion at right angles to the electric motion, as the Aether circulates round the sun, because this motion may be represented as taking place from west to east of the sun, while the electric vibration takes place from north to south, or transverse to the line of propagation.

We have, however, learned that the Aether has an electro-magnetic basis, and therefore the rotation of the Aether gives rise to electro-magnetic currents; hence the motion west to east is really the motion of electro-magnetic currents which circulate round the sun. As these are at right angles to the line of propagation, and we have seen that they are at right angles to the electric vibration, it follows that all three are at right angles to each other, which is in accordance with the requirements as laid down by Maxwell.

We have considered these vibrations, first, from the view of the solar system as a whole in its relation to the universal Aether; but the same principle holds good if considered from the aetherial atomic standpoint. For if we take a line of force, composed as it is of aetherial vortex atoms, and suppose them to be rotating, we know that by that rotation there will be a tension due to that rotation, and Maxwell has shown this tension is due to magnetism, as in his standard work he says: "This magnetic force is the effect of the Centrifugal Force of the Vortices."

So that by postulating a rotatory movement for the Aether around the sun, as we have done in Art. 92, we have not only solved the problem of all planetary and solar magnetism, but we have also solved the problem of the relative motion of the Aether and the earth, and also given for the first time (though it may be in an incomplete form) a physical explanation of that part of the electro-magnetic theory of light, which has hitherto been unexplained from the purely physical standpoint.

Such results, therefore, supported as they are by the direct experiment of Michelson and Morley of America, justify us in concluding that the conception of a rotating Aether is not only philosophically correct, but is in actual accord with experimental investigation and research, as indeed it ought to be.