tions suggested by the manifest signs of violent volcanic action on the moon in former ages, when neither water nor air existed in any considerable quantity, let us pause for a moment to discuss the remarkable result attained by Gussew.

If we suppose that there really is a bulging-out on the earthward side of the moon to the enormous extent indicated by Gussew's measurements, we have a singular problem to inquire into. For theoretically, as Newton showed long since, the moon ought to be in shape what geometricians call an ellipsoid. The earth's globe is slightly flattened one way, and we call such a figure a spheroid; but now suppose that besides being compressed at the poles, she were also (as some think she actually is) compressed (but to a much smaller degree) at two opposite parts of the equator, so that the equator itself was slightly oval; then she would have her shortest diameter, as now, the polar one; her longest diameter would be the longest diameter of her oval equator; and she might be said to have an intermediate diameter, viz., the shortest diameter of her equator. So it should be, says Newton, in the case of the moon. She should be most compressed at the poles, or nearly at the north and south points of her disc; her longest diameter should be the one turned towards the earth; and a thwart diameter lying nearly east and west would be her third or intermediate diameter. Then he calculated the length of these several diameters, and found that the shortest would not differ more than sixty-two yards from the longest. This is something very different from the seventy miles resulting from Gussew's measurements.

If then that monstrous hill exists, we must look for its origin in some extraneous cause, since we see that a globe assuming its natural figure under such conditions as prevailed in the moon's case would present no such excrescence. We believe we are justified in saying that the photographic evidence is accepted by Dr. De la Rue himself. In fact, when two pictures of the moon, in opposite stages of her balancing, are looked at, the stereoscopic view shows Gussew's great hill actually standing out as it were, before the very eyes. We venture to quote Sir John Herschel's account of the principle of this method, because of the singularly effective way in which he presents the matter. He

says: "Owing to the libration of the moon, the same point of her surface is seen sometimes on one side of the centre of her disc, and sometimes on the other, the effect being the same as if, the moon remaining fixed, the eye were shifted from right to left through an angle equal to the total libration. Now this is the condition on which stereoscopic vision depends, so that by choosing two epochs when the moon is presented in the two aspects best adapted for the purpose, and taking separate and independent photographs of it in each aspect, the two, stereoscopically combined, so completely satisfy all the requisite conditions as to show the spherical form just as a giant might see it, whose stature was such that the interval between his eyes should equal the distance between the place where the earth stood when one view was taken, and that to which it would have been removed (the moon being regarded as fixed) to get the other. Nothing can surpass the impression of real corporeal form thus conveyed by some of these pictures as taken by Mr. De la Rue with his powerful reflector, the production of which (as a step in some sort taken by man outside of the planet he inhabits) is one of the most remarkable and unexpected triumphs of scientific art."

Both the measurement and the simple contemplation of the stereoscopic pairs of lunar pictures appearing to indicate the same result, we may proceed to inquire under what circumstances that result may have been brought about. The true explanation can scarcely fail to be a singular one, whatever it may be; so that if we are led to a view which may appear sensational, this must not be regarded as a surprising circumstance.

Now let it be noted that whatever ideas we may form as to the past condition of our earth and the other members of the solar system, we can scarcely refuse to admit the general theory that in long past ages every one of these globes was in a condition of intense heat. That our earth was formerly liquefied by intensity of heat, is the opinion of all who have carefully studied her surface; and there are few men of science who do not, after examining the evidence, conform to the theory of Meyer, that the earth was formerly in a vaporous condition. Assuming that as our poet laureate has expressed the theory

This world was once a fluid haze of light,
Till toward the centre set the starry tides
And eddied into suns, that wheeling cast
The planets-

we can form no other conception of our earth's primal condition than as a vapor globe. Our moon likewise affords abundant evidence of having once been in an intensely heated state. And doubtless there was once a time when the earth and moon were both (at the same time) vaporous through intensity of heat.

Now we have not gone back to that far distant epoch for the purpose of seeking there for the secret of the moon's present figure. It appears to us reasonable to trace back to such an epoch the singular law of the moon's rotation, whereby she always keeps the same face turned towards the earth; for far off though that epoch may be, it is not separated from our time by so enormous a lapse of ages as could be required to "brake" a rapidly rotating moon to the moon's present strangely slow rotation rate. In the distant era then, when the moon was a vapor nucleus within the great vapor-globe which was at some future period to form the earth we live upon, the moon thus involved learned to rotate synchronously with her revolution. But gradually the earth's vapor-globe shrunk in its dimensions until the moon was left outside-or we may say that the vaporous envelopes around the two chief nuclei so far shrank as no longer to be anywhere intermixed. From this time forth the moon must have cooled more rapidly than the earth; and the time must at length have arrived when the moon had become an opaque orb, while the earth on which we live was still a sun. Even at this early stage of our existence the moon must have so rotated as to turn the same face towards the earth's then glowing orb. But now a circumstance has to be considered which, startling though it may seem at first, is yet consistent with what has been ascertained respecting the sun and other bodies. There is a great mass of evidence tending to show that our sun expels matter from his interior with a velocity sufficient to carry such matter entirely away from him. This has been shown by the microscopic and chemical structure of meteorites, by their paths and rates of motions, and by many circumstances which will be found detailed at length in the article called "Meteors, Seed-bearing and

Otherwise," in the Cornhill Magazine for November, 1872. It is also very strikingly supported by the behavior of the socalled eruption-prominences of the sun. Passing from the sun to the major planets which even now seem to have some of the qualities of subordinate or secondary suns, and must certainly have been such long after the earth and her fellow minor planets had cooled down into the condition of habitable worlds-we find very striking evidence to show that these minor suns or major planets erupted from their interior the material of meteor systems and of those comets of small period which have been called the comet-families of the major planets. The evidence on this point will be found fully detailed in the article called

"The Recent Meteor Shower and Meteor

Showers generally," which appeared in the Cornhill Magazine for January last; and the circumstance will there be found noted, that we need not inquire into the dimensions of a body, in considering the possibility of its expelling matter from its interior with a velocity sufficient to carry such matter altogether away; since, in point of fact, the inferiority (for instance) of the major planets compared with the sun, is compensated by the inferior attractive power which their eruptional forces have to overcome. All that is required is a sunlike condition with respect to heat; granting this, a small globe like the earth, or even so small a globe as the moon, would be as competent to expel matter to great distances from its interior, as the major planets, or as the sun himself, or even as an orb like Sirius, exceeding our Isun at least a thousand times in volume.

So long then as our earth continued in a sunlike state, she would probably expel matter in all directions with a velocity small indeed compared with the velocity of matter erupted from the sun, but quite as large relatively to the attractive power of the earth. This process of continual eruption would not exhaust the earth, simply because it would be compensated by arrivals from without; and moreover, far the greater quantity of the erupted matter would doubtless fall back upon the glowing orb of the earth. But it is manifest, that whatever matter was erupted directly towards the moon, so as to fall upon her, would recruit her mass. As we must assume from the known mass of the earth that she was for ages in a sunlike

condition, we must believe that during those ages that face of the moon which was continually directed earthwards received no inconsiderable supply of erupted matter. For it must be remembered that when the process began the moon was much larger in volume, though considerably less in mass, than at the present time. She would, therefore, at that time intercept a much greater proportion of the erupted matter. Moreover, since, after she had shrunk into a semiplastic but still growing orb, the moon must have continued for a very long time subject to this rain of earth-born missiles, there is reason for regarding as very considerable the quantity of matter by which her bulk was thus increased. Moreover, if it be remembered that the meteoric missiles thus expelled from the earth would necessarily be exceedingly hot, probably liquid even before their fall, and certainly liquefied at the moment of collision with the moon's surface, we find à priori evidence for that very downfall of liquid drops, of which, as mentioned above, the present aspect of the moon seems to afford evidence. It is certainly a noteworthy circumstance that a theory devised to explain a most striking peculiarity of the moon's globe, should account also for a feature, not less striking, which had not been specially in view when the theory was invented.

We must pass, however, from these considerations, because the evidence on which they have been based is too slight to warrant any prolonged or exact discussion respecting them. But a few words remain to be said on the question which originated the strange theories devised to explain why the moon at present shows no traces either of oceans or an atmosphere.

We have said that on our earth the law seems established that where there is no water there are no volcanoes. May it not be, however, that this law does not extend to the moon? Mr. Mathieu Williams, whose work, The Fuel of the Sun, has suggested many new and striking considerations respecting the celestial orbs, has brought to bear on this question an experience which very few students of astronomy have possessed-the knowledge, namely, of the behavior of fused masses of matter cooling under a variety of circumstan"I have watched the cooling of such masses very frequently," he says, "and have seen abundant displays of miniature

ces.

volcanic phenomena, especially marked where the cooling has occurred under conditions most nearly resembling those of a gradually cooling planet or satellite-that is when the fused matter has been enclosed by a resisting and contracting crust. The most remarkable that I have seen are those presented by the cooling of the tap cinder' from puddling furnaces. This, as it flows from the furnace, is received in stout iron boxes (called 'cinder bogies'). The following phenomena are usually observable on the cooling of the fused cinder in a circular bogie. First a thin solid crust forms on the red hot surface. This speedily cools sufficiently to blacken. If pierced by a slight thrust from an iron rod, the redhot matter within is seen to be in a state of seething activity, and a considerable quantity exudes from the opening. If a bogie filled with fused cinder is left undisturbed, a veritable spontaneons volcanic eruption takes place, through some portion, generally near the centre, of the solid crust. In some cases, this eruption is sufficiently violent to eject small spurts of molten cinder to a height equal to four or five times the width of the bogie. The crust once broken, a regular crater is rapidly formed, and miniature streams of lava continue to pour from it; sometimes slowly and regularly, occasionally with jerks and spurts, due to the bursting of bubbles of gas. The accumulation of these lavastreams forms a regular cone, the height of which goes on increasing. I have seen a bogie about ten or twelve inches in diameter, and nine or ten inches deep, surmounted in this way by a cone about five inches high with a base equal to the whole width of the bogie. These cones and craters could be but little improved by a modeller desiring to represent a typical volcano in eruption."

The aspect of the moon's crater-covered surface certainly accords better with the supposition that active processes like those described by Mr. Williams were in operation when that surface was formed, than with the theory that slow and intermittent volcanic action like that with which we are now familiar on earth, modelled the moon's surface to its present configuration. In the former case water would not have been needed, and vaporous matter would not have been expelled to an extent irreconcilable with observed phenomena.

It is manifest that we have in the moon

THE object of this article is to point out how modern scientific doctrines may be expected in the future to affect the personal liberty of individuals in the matter of marriage. Up to the present period of the world's history, the social struggles of mankind have been principally directed towards the attainment by the individual of an ever-increasing emancipation from the restraints exercised over him by other members of society. One of the most prominent ideas of Christianity is the personal responsibility of each man for the salvation of his own soul, and, as a consequence, his mental independence from others;-any other idea than that of the complete independence of his bodily frame would not be likely to present itself to the mind until evolutional doctrines had obtained a considerable prominence. But these modern doctrines go to show that our mental, as well as our bodily structure, is the direct outcome of that of preceding generations, and that we, the living generation, are like the living fringe of the coral reef resting on an extinct basis afforded by our forefathers, and shall in our own turn - form a basis for our descendants. We are now beginning to realize that the members of a society form a whole, in which the constituents are but slightly more independent than are the individual cells of an organic being; and indeed, according to the belief of many great physiologists, each cell is to a certain extent a distinct individual, and vast numbers of such individuals are in fact associated in a colony for the purpose of mutual assistance, and form in the whole a living organism. I have in this article assumed the truth of evolutional doctrines, and persons who do not accept them will find the force of what I have to say either much weakened, or wholly destroyed.

Mr. Freeman has recently remarked,* that the temptation which besets our particular society is a temptation to make too little of the commonwealth, to set the interests of the particular member before that of the whole body, and generally to put what is private first and what is public

"Fortnightly Review," April 1873.

second. The laws of inheritance have now shown us the intimate relationship which subsists between our progenitors, ourselves, and our descendants; it appears, then, likely that we shall hereafter be driven to resist the temptation above referred to, and shall, in the endeavor to promote our descendants' welfare to some extent, subordinate the interests of the individual to that of the commuuity, in the initiation of new restrictions to liberty of marriage. It will be objected that the regulation of the daily increasing intricacies of our civilisation does now afford, and will still more in the future afford, sufficient, or even too much, to fully occupy attention, and that the future must ever be allowed to develope itself without attempts on our part to influence it; but in answer to this I may point out that in compulsory education, vaccination, and sanitary matters we are even now making attempts to control the future, and that as our scientific knowledge becomes more extensive, and the consequent power of predicting the future increases, we shall see the wisdom of extending further and further the scope of this class of legislation. Simultaneously with the diffusion of the belief in the truth of the doctrine of heredity, will come the recognition that it is as much a duty to transmit to the rising generation vigorous minds and bodies, as to hand down to them a firmly constituted society and government-to which latter point attention has hitherto been almost exclusively directed.

It is in his own case alone that man ventures to neglect the knowledge he has acquired of the beneficial effects of careful breeding. Dr. Prosper Lucas ob

serves

"Malheureusement, l'homme dans le rapprochement sexuel des animaux, mû par son intérêt, considère l'avenir et les progrès de la race, tandis que les familles, malgré des intérêts, plus graves et plus sacrés, n'ont en vue, dans le mariage, que le présent immédiat et que l'individu."

And this neglect appears likely to continue so long as the pernicious idea generally

*Traité de l'hérédité naturelle du système nerveux." Baillière, Paris, 1850, p. 914, vol. ii.