and I'll go wi' ye to the world's end, what- | nothink, nor nobody, that's what ye won't. ever father may say against it, that I will! Not if sobe 'twere her Majesty the queen he'll give in, I know he will. And if as had a put off comin' to tea, arter sayin' you're to be poor (and you will be very as 'ow she'd be here, which it's sure I am poor indeed, Gilbert, sha'n't you?), I'll that she wouldn't do no such a thingmake very little do, and dress in quite God bless her!" added Mrs. Seddon common things. See, I've begun already loyally. -only look at my gown just to try, and because I thought you would like it. And why didn't you come back and see me that day after the flood, Gilbert? it was very cruel of ye; and oh, how I did cry that evening, thinkin' of ye that didn't think o' me, when I saw Lizzie come back all alone! . . . What for don't ye speak to me, Gilbert? You're glad to see me, dear, ayn't you?" cried Rosy, in sudden terror at getting no answer.

"Glad!" said he, bending over her, "I should think I was glad! Only I'm a little bit in a maze still, dear, and there hasn't been much room, has there, yet, Rosy, for to put in a word?" And he pressed the hand which he held fondly, as the open street did not admit of a more lively demonstration for the present.

"Ah, you're laughing at me because I run on so! But you shall see as it isn't only words, but that I do care for ye, Gilbert, wi' all my heart and soul," said she tearfully, as they reached Mrs. Seddon's house.

"And how ever did you turn up here at Knowlton to-night?" inquired Gilbert, as they lingered still outside the door for a few words more together.

"I've got a good bit o' news to tell ye, Rosy," said Gilbert presently. "There's been an old uncle o' ourn as died up in Yorkshire, the t'other day. We hadn't seen or heerd of him for years, and didn't think nowt about him; but the lawyer telled me this evening as he hears we've a come into summat; 'tayn't a very deal - betwixt three and four hundred pounds - but 'twill pretty nigh set us straight at the Low Lees, for Sir John has a been main kind about the rent and offered another farm; that isn't not a dairy one neither, dear, and nigh to Knowlton," he added, smiling. "Or what would ye say if we went off to Canada, and tried a' fresh wi' a new start, Rosy?"

The girl's face fell a little, but she recovered herself. "I'll go wi' ye there too, Gilbert, if ye've certain sure set your mind that way. But it's a long way off out there over the big salt sea and the savages, isn't it?" she said, with a little shiver.

"Nay, lad, thee mustna run off that fashion. I canna spare thee nor her neither. Stay a bit. I'm an auld 'ooman and not long for this world; thou'rt like a son to me, and it shanna be the worse for "Why, to be sure, because Cousin Sed- thee and her if ye stops where I can see don she axed me, knowing how I were yer bonny faces now and then," said Mrs. fretting, and how I didn't know how to Seddon, more moved than she liked to compass meetin' ye again, you hard-show, or, indeed, than she had ever felt hearted Gilbert, that wouldn't stir an inch before in her life. ""Twould be a poor nor nothink not to see me! And she thing as Gilbert Sherard should ha' risked wrote as how couldn't I get a bed here his life for to drag us three out o' the wi' a friend for watch night; for 'twould flood, on'y to be drownded out o' house do me a deal o' good to hear the good and land hisself, and his wife too, by it. things spoke to me i' th' chapel, me that And that they shanna be, or my name wanted them badly! You know she speaks ayn't Sarah Seddon !" out, does Cousin Seddon ! But it was true too what she wrote, all the same. And then she said she'd do what she could for me when sobe she'd got me here."

"Well!" cried the old woman with a smile, as the pair walked into her little room hand in hand; "so you've come back to supper, Gilbert, as good as yer word! I thowt as meybe ye wouldn't forgit this time; and I thowt too, though ye went out one, ye might come back two! So I'm not unprepared; there's two plates for ye, over and above me and my old man, what's arter all gone out wi' some neighbors to-night, he is. But you'll miss

F. P. VERNEY.

born of the earth many millions of years | seeing further that this process is of neago, and has been retreating ever since cessity one which takes place more and from the parent orb; how these views more slowly as time proceeds, we are jusare related to the nebular hypothesis of tified in looking back to a time when it Laplace; and what bearing they may progressed far more quickly than at preshave on astronomical and geological es- ent, in considering that over the whole intimates of past eras in the earth's history. tervening period - many millions of years An eloquent lecture by the astronomer it has been at work, and finally in inroyal for Ireland has done much to increase the interest with which these questios are viewed; indeed, it may be doubted whether many who are now inquiring about these matters had heard of them at all, before Dr. Ball brought them before the attention of the audiences to whom his lecture has been addressed.

I propose to sketch and only to sketch, for the subject is one which would require more than a full number of the Contemporary Review for adequate discussion the ideas resulting from the researches of Mr. George Darwin, noting how they are related to former views respecting the development of the solar system, and how they bear on certain other astronomical and geological theories. At the outset I may remark that I cannot altogether agree with the opinions expressed by Dr. Ball, and to some degree by Mr. Darwin, respecting the manner of the moon's birth; but as to the general theory to which Mr. Darwin's researches have led there seems very little room for doubt or question.

ferring that no unimportant part of the earth's present mass has been derived in this way from meteoric aggregation.

Now, among other processes of change that are taking place in the earth and her dependent or associate orb, the moon, are two others, discovered in comparatively recent times, though not quite so recently as some might infer from Dr. Ball's account. About a quarter of a century ago Professor Adams, co-discoverer with Leverrier of the distant Neptune, announced that he had discovered an error in Laplace's discussion of the so-called acceleration of the moon, and that when this error was corrected the acceleration could not be entirely accounted for by the theory of gravitation. It was presently shown by the eminent astronomer Delaunay (not to be confounded for a moment with the Delaunay who has recently insisted on the inferiority of the weaker sex) that this unexplained part of the acceleration of the moon may be explained on the assumption that it is not the moon which is gaining, but the earth which is In carrying back our thoughts to the losing time; in other words, that the great past of the earth, our most trustworthy terrestrial clock, the rotating earth, by guide (though we must be careful in fol- which we measure time, is not going at a lowing even this guide) is evidence found uniform rate, but is gradually losing its in the study of processes actually taking rotation spin. Laplace's assertion that place at the present time. For instance, the earth's rate of rotation, so far as aswe find that the earth is slowly cooling. tronomy can measure, is appreciably conWe can, therefore, safely go back to a stant, was based on his investigation of time when she was much hotter than she the moon's so-called acceleration. Supis at present; and though we may not be posing that no part of this change reable to assume confidently that her tem-mained unexplained, when solar and planperature was ever so great as to cause every particle of her substance to be vaporized, may infer even that, if other features actually existent seem readily explicable on such an assumption. Again, we find that the earth gathers in every year hundreds of millions of meteoric masses of greater or less weight, down to bodies weighing only a few grains; and we know from the orbits followed by the greater number of these that they belong to systems travelling around the sun on paths of such a nature as to forbid us from believing that they were originally expelled from the earth. Seeing, then, that the earth is gathering in materials from without, though now at a very slow rate, and

etary perturbations of the moon were taken into account, he naturally inferred that the great terrestrial timepiece is keeping most perfect time. Finding, on the contrary, that a part of the acceleration does remain unexplained, we are justified in assuming, as at least a possible interpretation of the excess of acceleration, that our chief timepiece is losing time. Delaunay pointed to the tides as a probable and sufficient cause of this change - the great tidal wave carried, not bodily, but still swayingly, against the direction of rotation, checking the earth's rotation spin slowly but "exceeding surely."

Next, it was shown that, accompanying this change, there must be a gradual loss

of

vaporous through intensity of leat. If that were so, the earth's volume would then have been much greater than at present, even though her mass may have been, as it probably was, much smaller. What we see now in the giant planets, long after the moon-generating part of their career, seems to confirm this view, which a priori reasoning renders probable. We have also to take into account the smaller mass of the earth at that remote period, before those many millions of years throughout which the earth has been gathering year by year hundreds of millions of meteoric masses.

of lunar motion, accompanied by a grad. | look the probability that the separation of ual recession of the moon.* the moon from the earth took place when Elsewhere I may take occasion to de-a large part of the earth's mass continued scribe more at length these two processes of change. Here, for the present, let it suffice to note that astronomy recognizes them as taking place, and that they therefore are among the processes which we may carry back in imagination to a very remote past, that so we may recognize what probably was the initial condition at any rate, a very early condition the orbs in which they are taking place. Of course it is an obvious thought that if the moon is thus receding now, and has been receding in the past, she will one day part company with the earth altogether, and that she was at one time quite close to the earth, and even a part of the earth's mass. Considering, also, the change in the earth's rotation period, and carrying our thoughts as far back into the vistas of the past for this change as for the other, we see a time when the earth was rotating so fast that its equatorial parts were barely restrained by gravity from yielding to the tremendous resulting centrifugal tendency. A simple calculation shows that if the earth rotated once in about one hour and a third, retaining its shape unchanged (which last it could not do unless very much more rigid than it is), a body at the equator would be absolutely weightless. But a much slower rate of rotation than this would suffice to break off the equatorial regions. If the earth rotated once in about three hours the equator would increase its distance from the polar axis, the centrifugal tendency (the rate of rotation continuing) would be greater and the surface gravity less, and the material of the equatorial surface parts would be separated from the rest of the earth's substance.

Dr. Ball follows Mr. Darwin in talking about this rotation rate-one spin in three hours - as that existing when the moon's mass separated from the earth. If we assume the earth at that stage of her existence to have been, apart from centrifugal effect, of the same volume and mass as at present, her substance possibly liquid, but not in great part vaporous, this estimate would be justified. But it appears to me we must not over

This may seem inconsistent with what we said

above about the lunar acceleration which astronomers have endeavored to explain. But this acceleration is one of the temporary changes which the moon's motion undergoes. It alternates with a similarly temporary retardation, in periods of great length indeed, but not to be compared with the enormous time-intervals which we are considering.

Now, with a larger and less dense orb, a slower rotation rate - probably a rotation rate very much slower- would have sufficed to cause the earth to part with matter from its equatorial regions, where, of course, the centrifugal tendencies resulting from over-rapid rotation would be most pronounced.

I have been in the habit during the last ten years of pointing out when lecturing on the moon that she probably had her origin as part of the vaporous or partly vaporous mass whence the earth also was formed, and that to this origin she owed the peculiar rotational motion which keeps the same face ever directed towards the earth. I can see nothing in Mr. Darwin's researches which should lead us to forsake this, the most natural interpretation of the moon's origin; on the contrary, the vast duration of the past periods necessary for the increase of the moon's distance from actual contact with the earth to her present orbit, and for the increase of the terrestrial day from three hours to twenty-four, suffices of itself to assure us that the earth at that remote time must have been in great part vaporous. The giant planets also, as I have already hinted, tell the same story, for though they have thrown off their moons

Saturn perhaps has not quite finished the work - they are still, as we can see from their small density and their aspect, in great part vaporous. When they were beginning the work of moon-formation, many tens of millions of years ago, they were, we may be sure, still hotter, and therefore a much larger portion of their mass was vaporous.

But it is the manner of the moon's birth, as suggested by Mr. Darwin (Dr. Ball accepting the suggestion as probably sound), which seems to me least likely to

accord with the probable manner of the subsequent behavior?
moon's generation, and also to correspond
least with a posteriori evidence.

Each particle,

each globule of molten matter, would behave just as the moon, according to the theory we are considering, has actually behaved. It would begin from the first moment of its separate existence to retreat slowly from the earth. Long before the tidal wave had again grown sufficiently high to throw off spray, the spray last thrown off would have passed beyond its reach. Again, each of the tiny globules thus thrown off from the earth would at first travel nearly in the plane of the earth's equator (later influences would modify

this relation considerably). Thrown off with slightly varying direc tions and degrees of velocity, the bodies expelled on opposite sides at one of these earth-spasms, would before long have spread themselves all around the earth, some gaining on the main body, others losing. Probably before the next flights of cosmical spray left the earth, the bodies last thrown off would form a tolerably uniform very narrow ring around the earth.

*

Mr. Darwin pictures the earth rotating once in three hours, with a double tidal wave (a wave affecting the fluid substance of her entire mass), raised by solar action. Such a wave, synchronizing with what may be called the pulsation period of the earth (with the dimensions she then had), would get higher and higher, just as a pendulum, receiving a succession of minute but well-timed impulses, swings farther and farther, until at length cohesion would no longer be possible, and the mass out of which the moon was one day to be formed was thrown off. The considerations I have indicated above would not affect this reasoning; they would only modify our views as to the size and condition of the earth when the moon's mass was thus liberated, and therefore as to the rate of the earth's rotation spin at the time, and the period of the moon's first free revolution. But there is a more important consideration, now to be taken into account, which forbids us, I think, to This process would have continued bebelieve that the moon's mass was thus tween certain definite epochs - the first thrown off, as it were, at a single effort. being the time when the earth's rotation The monstrous tidal pulsation which began to approach to synchronism with would undoubtedly take place under the her pulsation period, the last being the conditions described, would inevitably time when there began to be no sufficient lead to the throwing off of a small mass approach to synchronism (in the mid-inlong before it had attained swing enough, terval only would there have been perfect so to speak, to throw off such a mass as synchronism). This period must have the moon's one eighty-first part of the lasted for a very long time - probably for entire mass of the earth. Most probably, millions of years. When it was over, too, the crests of each tidal wave would what was the condition of the matter throw off a mass of matter at about the which had been thrown off from the same time, forming, for the time, two earth's mass? Manifestly it must have small moons instead of one large one. formed at that time a series of close conStill more probably, in my opinion, the centric rings of tiny satellites. Probably crest of each wave would scatter cosmic the rings were so close that, though each spray rather than a single great globular was very narrow, they formed a continumass. After each wave had thus swollen ous flat and rather broad ring. But, and eventually burst into spray, it would whether this were so or not, it is certain gradually subside for a while, the solar that the outermost and innermost ring of tidal impulses no longer quite synchroniz- the series would form the boundary cir ing with the earth's tidal pulsation; but cles of a flat and rather broad ring system presently the waves would begin to grow of small bodies, closely resembling in apagain, would flow larger and larger, until pearance (as seen from a great distance) again a flight of small masses would be the Saturnian ring system, and having a flung from the summit of each. Again real structure precisely like that which and again the process would be repeated, the researches of Benjamin Peirce and until at length the earth's constantly the Bonds in America, of Clerk Maxwell changing rotation rate would cause the and others in this country, have proved sun's tidal action no longer to synchronize that the Saturnian ring system actually with the earth's pulsation period. Then, and then only, the earth would cease to throw off cosmical spray.

Now what would be the condition of the matter thus thrown off, and what its

has.

That is the period of vibration of her mass after any impulse (affecting the whole earth) had been rehave had such a pulsation period as the vibrating subceived from without. The earth would as certainly stance of a bell has.

changes in the appearance of the rings, and probably the recent development of the inner dark ring, may be due to processes of this kind - collisions among the satellites, and consequent loss of vis viva by the entire system.

It seems to me, on the one hand, so teen years ago, in my treatise on Saturn clear that the process suggested (with (p. 126), and it was there shown that great plausibility) by Mr. Darwin and Dr. Ball must really have taken place in such a manner as to produce a ring such as I have described, and, on the other hand, it is so certain that the Saturnian ring system is of this nature, that I feel persuaded we have here been led-by paths along two lines of research, each of great difficulty, apparently tending in very different directions to the explanation of the mystery of Saturn's rings, and of the much deeper mystery of the origin of worlds and moons. Sixteen years ago, in the preface to my treatise on "Saturn and its System" (my first work), I pointed out that probably in the study of the Saturnian rings we might find an interpretation of the manner in which the solar system itself had been developed. My prediction, if such it can be called, has not been exactly fulfilled, though the relationship I indicated between the two problems has been confirmed. For, instead of the study of the Saturnian ring system having thrown light (except reflected light) on the origin of worlds and moons, it would seem as though the study of the origin of the moon had thrown light on the Saturnian rings.

Be this as it may, there can be very little question, I believe, that the moon was not formed at a single effort, as Dr. Ball has suggested, but that a series of rings was first formed, constituting a single flat ring system. The formation of the moon from such a system of rings would result from the gradual process by which the number of the minute bodies forming the ring system would be reduced by collisions. If the ring system was (as seems probable) immersed at the beginning, and for a long time, in the vaporous outskirts of the earth, this process would be less slow than it otherwise would have been. Satellite after satellite would coalesce with neighboring satellites; probably, centres of aggregation would be formed, which would absorb wandering satellites in the ring system still more effectively. Every combination of the kind, by changing the period of revolution of the mass thus formed (for at every collision there would be a loss of vis viva) would tend to hasten the change of the ring system into a single orb. It is no new idea that such a process as this took place, no mere attempt to reconcile new results with views previously entertained. The occurrence of such changes as I have here described was indicated by me six

The formation of the moon, whether in this manner, which appears to me much the more probable, or as a single catastrophic event, must have occurred at so remote a period that the earth's rotation (carrying back over this enormous interval of time the process of retardation which has certainly been in progress) must, when the moon was first formed, have been much more rapid than at present. The moon's period of revolution, also, must have been very much shorter than it now is. From and after that era, the processes of change must have been those which Mr. Darwin has described, and which Dr. Ball has pictured (with coloring in some parts perhaps tant soit peu exaggerated). We have no occasion to explain, as the latter savant does, how the earth's frame recovered from the shock of the moon's genesis, or how the scar left on her then plastic surface, where the moon's mass had left her, was presently healed by the "gentle ministrations" of the mutual attraction of the particles forming her substance; * for no such scar would ever, according to our view, have marred the fair surface of the earth. But subsequent changes would have been the same in whichever of these two ways- -the sudden or the gradual - we suppose the moon to have been formed.

According to either view, it is by no means clear that the moon's rotation period would have been the same as her period of revolution around the earth, as is now the case. But it is certain, that from the beginning of her existence as an independent orb, the moon must have been at work in raising a tidal wave, and at first far more actively even than now. Not only would she have raised a higher wave, because nearer to the earth, even had the earth been then what it is now; but since the earth must then have been in great part fluid, the moon would from the beginning do what the sun had for countless ages been doing-she would

"By these gentle ministrations," says Dr. Ball, "the wound on the earth would soon be healed.

the lapse of time, the earth would become as whole as testify to the mighty catastrophe."

ever, and at last it would not retain even a scar to