ing the millions, or thousands of mil-ery; there are iron vessels on every lions, of years for which that matter ocean, and objects of every size made has existed, it has perhaps only once of iron, from the smallest nails up to become so heated, owing to circum- hundred-ton guns. There is also at stances which we may describe as acci- this moment, and every moment, a good dental or casual, as to have acquired deal of hot iron on the earth. While the ample light-dispensing power of I write, iron is doubtless flowing from a sun. It is, however, possible that blast furnaces in England, Wales, and such periods of light-radiating capacity Scotland; while I write, ingots of should have occurred more than once; white-hot Bessemer steel are being they may possibly have occurred sev- dealt with under the steam-hammer or eral times throughout the ages of time in the rolling-mills; while I write, past. Nor is it likely that the last phe-horse-shoes are being forged, and, at nomena of this kind have yet arrived. each moment, in one way or another, The sun, after the lapse of uncounted pieces of iron of every temperature years, will lose all its heat and pass could be found, from those which are into a black, dark mass. In that form as cold as the iron apparatus used by it may endure for an epoch so pro- Professor Dewar in his experiments in tracted that the spell during which it the liquefaction of air, up to the glitterhas acted as the luminary to our system ing melted steel which is poured from will appear but a moment in compari- the tilted converter. But, it must be son with the dark ages which succeed admitted that the highly heated pieces the solar splendor. But we can con- of iron bear a very small proportion inceive that the darkness, which is the deed to the total mass of iron in the doom of our system, need not necessa- world at any moment. No doubt there rily be eternal so far as its materials are many tons of iron now white-hot, are concerned; it may be that again in but there are many millions of tons of the course of its wanderings through iron which was once white-hot, and is space, the tide of chance may at length now no warmer than the air around it. bring the dark and tremendous globe so At certain phases in its history every near some other orb that another col- piece of iron has to undergo the operlision should take place with appalling ation of being raised to incandescence, vehemence. The solid materials shall or even of being transformed into a again become transformed into a stu- liquid. But the laws of cooling are pendous glowing nebula, and then, in such that, as soon as the opportunity is the course of the tedious contraction of afforded, the iron parts with its redunthis nebula, another protracted period dant heat and returns to a stable conof brilliance will diversify the career of dition, in which it is at the temperature this great body, and may last long of the air. Now, suppose that some enough for the evolution of planets and percipient being, who was viewing this of whole races of highly organized earth from above, could only see iron creatures. The essential point for our when it was red-hot, or white-hot, but present consideration must not be mis- that he had every facility for perceivunderstood. A little reflection will ing such iron as happened to be in this show that any periods of brilliance must condition. With such faculties he be regarded as exceptional periods in would, no doubt, be able to discern the history of each body. Think, for here and there a stream of molten iron instance, of all the iron on the surface issuing from a blast furnace, or perof the earth. There is the iron in the haps to witness the operation of the ore; there are the great stores of pig-forging of an anchor under the steamiron lying ready for use; there are the vast bridges which span our rivers and straits; there are the thousands of miles of railway lines; there are the countless wheels and pieces of machin

hammer, to watch the rolling of the plates for an armor-clad, or to see the more humble operations of the blacksmith or the nail-maker. But he would surely form an entirely erroneous im

pression as to the quantity of iron on luminosity is a characteristic. In such this earth, or as to the extent in which cases only will the orbs be visible.

The instructed astronomer will, therefore, believe that the non-visible orbs must be hundreds, thousands, or perhaps millions of times more numerous than those which he can see. When we remember that, by our telescopes and on our photographs, we can discern something like one hundred million luminous stars in the sky; when we remember that every one of these is

incident in the career of the body from which the light emanates; and when we further believe, as believe we must, that for each one star which we can

it was employed in the varied purposes of the arts, if he concluded that there were no iron on our globe at all except that which happened at the moment to be in that particular incandescent state in which alone it was visible to him. If he were gifted with reasoning powers he would say, "It is quite true that I can only see the iron while it is red-hot, but I know that for iron to be red-hot on the earth's surface is an exceptional the indication of a wholly exceptional and abnormal condition of a very temporary or intermittent character. No doubt, every piece of iron may have to be red-hot once, or more than once, but the total duration of such phases of thus see there must be a stupendous incandescence are quite insignificant number of invisible masses, then, inunder ordinary circumstances when deed, we begin to get some notion of compared with the periods in which the the extraordinary multitude in which iron is cold and invisible. I, therefore, material orbs are strewn through space. cannot refuse to believe that there must The theory of probabilities declares to be an amount of iron on the earth us with a certainty, hardly, in my opinwhich I do not see, but which bears a ion, inferior to that of optical demonproportion to that which I do see in stration, that even within the distance the ratio of thousands or millions to which can be penetrated by our teleone." Precisely similar is the way in scopes the visible stars cannot form which the astronomer who is properly the hundredth, probably not the thoufamiliar with the theory of probabilities | sandth, perhaps not the millionth part will approach the study of the stars. of the total quantity of matter. He will reflect that each mass of matter On the question as to whether space through the period of its existence must is finite, our observations with the telebe cold and invisible for by far the scope have but little information to greater part of the time; he will reflect give. The question here involved is that on rare occasions, separated by intervals of appalling length, certain The extent of space depends more exceptional conditions arise by which upon the facts of consciousness than this dark piece of matter may be so kiu- upon those of astronomical observation. dled that, for an epoch, long it may be It may, perhaps, simplify the discusin years but brief indeed when com- sion of the subject if we first of all pared with the span of told existence, consider the question as to whether the the body would glow as a star. Pro- quantity of matter in the universe may vided with this conception let us look be presumed to be infinite or not. on the universe with its millions of orbs. These orbs will be found in every phase possible to such bodies; but the enormous majority of them must, in accordance with the principles just laid down, be in the dark and invisible state. Out of some millions it may perhaps be concluded that, at any particular moment, a dozen or so might, by accidental circumstances, be in those phases of their several careers in which

rather of a metaphysical complexion.

We

can put the question into a perfectly concise form by reflecting that every particle of matter, whether solid, liquid, or gaseous, is composed of molecules. No doubt these molecules are so numerous that even in the air we breathe the capacity of a lady's thimble would contain a multitude of molecules so great that it has to be enumerated by billions. But we are not at present merely concerned with the actual number of mole

4267

cules that may exist in the atmosphere, | boundary, the imagination will equally even in its whole extent, or in the suggest that there is something on the whole earth, or in the whole sun. Let other side of that boundary from which us try to conceive the number of mole- you can commence again. It appears cules that are present in all the stars, almost equally impossible to suppose bright and dark, which exist not only that the journey could be carried on within those regions of space accessible forever as to suppose that it could ever to our telescopes, but elsewhere as well. be brought to an end. It was, howIn short, let us try to conjure up in our ever, long ago shown by Kant that imagination the kind of figures which | space was rather to be regarded as a are to express the total number of mol- form in which the human mind was ecules in the universe. Is that number compelled to regard objects than as a finite, or is it not? This is, perhaps, self-existing fact of external nature. one of the most fundamental ques- We have no power in our own contions in nature which could possibly be sciousness to surmount the difficulties proposed. Let us consider the con- of conception to which I have referred. sequences which would follow from They arise from the conditions of adopting a negative answer to this ques- our mental constitution, and reasoning tion. If we suppose that the number about space will do no more to remove of molecules was indeed infinite, then its mysteries than it will suffice to we are necessarily forced to admit at give to the man born blind a notion of once that space must be infinite too; the color scarlet. But mathematicians, for had space any boundary, then, since while fully aware of the imperfection the molecules do not admit of being of their powers of conception as regards crowded together beyond a certain ex- the facts of space, are still enabled to tent, it would be impossible that they frame a perfectly consistent theory accould exist in infinite abundance. cording to which the observed phenomAdopting the sound principle that we ena of nature can be presented within need not assume more than is necessary a space which is finite in dimensions. to explain the phenomena exactly pre- They are even able, as it were, to lay sented by our consciousness, it seems their finger upon the exact point in to me to be clear that the number of which the subjective difficulty has molecules of matter in the universe arisen. must be finite. The row of figures I must here be permitted to refer to which would express that number, a point in connection with the elements whatever it may be, is the most re- of Euclid. The beginner who studies markable descriptive constant which the universe possesses. It matters not for our present argument what may be the number of figures by which this number can be expressed. It may not be too large to be written even on the thumb-nail by the compendious method of notation now in general use.

Let us next see whether we can learn anything as to the extent of space itself. It is apparent that we seem to be in the presence of about equal difficulties whether we attempt to think of space as finite or infinite; for, imagine that you go up in a straight line into the sky, and on, and on, and on, in thought for millions of miles, it would seem that the journey ought to be endless; for, supposing that you try to conceive a

this work commences, of course, by learning the axioms, and reads without any feeling of discontent or querulousness such venerable truths as that "the whole is greater than its part." But, after a number of propositions of this eminently unquestionable but somewhat puerile kind, he is suddenly brought up by the famous twelfth axiom in which Euclid lays down the theory of parallel lines. Here is a statement of a radically different kind from such assertions as that "if equals be added to equals the wholes are equal." In fact, Euclid's notion of parallel lines is so far from being an axiom of the same character as these other propositions that it is quite possible to doubt its truth without doing any violence to our conscious

ness. The principle assumed in the inally started need not involve a jourtwelfth axiom cannot be proved, and it ney of infinite length. If we assume has been well remarked, that it indi- Euclid's twelfth axiom to be true, then cates the supreme genius of Euclid to no doubt the traveller can only get back have expressed this particular axiom in to the point from which he started as such language as challenges at once the the result of a journey of infinite length attention and the caution of the stu- which will have occupied an infinite dent. It may, however, be said that time. But now suppose that Euclid's nearly all our difficulties in connection twelfth axiom be not true, or suppose with the conceptions of space take their that, what comes to the same thing, the origin in the ambiguities which arise three angles of a triangle are not indeed from the assumption which the twelfth equal to two right angles, then the jouraxiom implies. Some modern mathe-ney may require neither an infinite maticians have gone so far as to deny lapse of time nor an infinitely great the existence of this axiom altogether speed before the traveller regains his as a truth of nature, and it is most im- original position, even though he is portant to notice that when free from moving in a straight line all the time. the embarrassment which the assump- Space is thus clearly finite; for a partion of Euclid involves, a geometry ticle travelling in a straight line with emerges which removes our difficulties. uniform speed in the same direction is It seems to show that space is finite never able to get beyond a certain limrather than infinite, so far as we can ited distance from the original position, assign definite meaning to the words, to which it will every now and then but it would lead me into matters some- return. Those who remember their what inconvenient for these pages if I Euclid may be horror-struck at the herwere to pursue the matter with any esy which suggests any doubt as to the further detail. I may, however, say sanctions by which they believe in the that it can be demonstrated that all equality of the three angles of a triknown facts about space are reconcil- angle to two right angles. Let them able with the supposition that if we fol- know now that this proposition has low a straight line through space, using never been proved, and never can be for the word straight the definition proved, except by the somewhat illogiwhich science has shown properly to cal process of first assuming what is belong to it, that then, after a journey equivalent to the same thing, as Euclid which is not infinite in its length, we does in assuming the twelfth axiom. shall find ourselves back at the point Let it be granted that this proposition from which we started. If any one is to some very minute extent an untrue should think this a difficulty, I would one; there is nothing we know of recommend him to try to affix a legiti- which shows that such a supposition is mate definition to the word straight. unwarrantable; no measurements that He will find that the strictly definable we can make with our instruments; no attributes of straightness are quite com- observation that we can make with our patible with the fact that a particle telescopes; no reasonings that we can moving along a straight line will ulti- make with our intellect, can ever demately be restored to the point from monstrate that the three angles of a which it departed. triangle may not as a matter of fact It is quite true that this seems to be actually differ from the right angles by a paradox, but it will not be so consid- some such amount as, let us say, the ered by the geometer. The truth it millionth part of a second. This does implies is indeed quite a familiar doc- no violence to our consciousness, while trine in modern geometry. But what it provides the needed loophole for is not so familiar to mathematicians is escape from the illogicalities and the that the restoration of the travelling contradictions into which our attempted particle to the point from which it orig-conceptions of space otherwise land us.

ROBERT BALL.

From The Cornhill Magazine.

THE SCILLIES AND THE SCILLONIANS.

useful herb which is to roast duck what the soul of a man is to his body. The words Daffodil, Narcissus, Mackerel, New Potatoes, or Wreck may also be tendered as substitutes more or less pleasant and appropriate; and all preferable to Scilly.

IT is perhaps unfortunate for the natives of these isles that by the exigencies of English pronunciation they are in some peril of being bracketed by the ignorant with the inmates of our lunatic asylums. But in fact the islanders In truth, however, no error could be might if they pleased revolt upon good more radical than to imagine the Scilgrounds against the accepted appella- lonians deficient in wit. We know but tion of their home-land. It is affirmed little about them in the olden time; by experts that in the old time the except that the Romans used their isles name was pronounced "Skilly." This, as a repository for Cornish tin, and perthough to the novel reader reminiscent haps burrowed locally also for the same of thin gruel, is at least more dignified mineral. But in the last few generathan "Silly." The word is derived tions the islanders have shown their from the Cornish "skoly " or " skully," abilities as smugglers, rogues, shipto scatter. This is fairly significative builders, pilots, and market gardeners of the hundred or two of black rocks in a way that ranges them far beyond and green islets which form the group, the borders of imbecility. One half spread as they are over a broad surface expects to find them an indolent little of water. But other derivations are community, enjoying their mild climate also in the field. There is "sylla," a after the manner of the people of conger eel, or "scylly," to separate; Hawaii. But I had not been a day in either of which may be at the bottom St. Mary's ere I had changed my opinof the nomenclature of the interesting little archipelago.

Here, then, is scope for the employment of the county councillors, whose recent institution in the capital of the islands has caused so much suspicion. By getting a stout lever under established custom, the councillors may do wonders, and in a year or two effectually remove the reproach which has hitherto for long lain upon the archipelago. They will also thereby perchance justify themselves and their existence in the regard of their fellow islanders. These view them as a pretext for a new rate merely. The council chamber is over the butchers' stalls in Hugh Town market-place. It is a suggestive location. Blood has been ere now spilt for more trivial grievances than this which has taken possession of the minds of the people. But let the councillors accommodate their views and actions to their situation, and all may yet be well. Let them rechristen the islands without delay. If the name must relate to their natural products, would the transition from "Scilly" to "Sage" be too abrupt? For in the local gardens I have seen much of that

ion in this matter, and at the end of a week methought a little of their energy might profitably be transferred to some of our mainland towns.

It is, of course, easy to reach the isles. During the early weeks of summer there is a steamer almost daily from Penzance to St. Mary's. This is more for the convenience of the fish trade, and the Billingsgate gentlemen who have it in charge, than for the visitors or the mails. Still, visitors may benefit by it though at some personal cost. The Atlantic off the Land's End is seldom as smooth as it might be. The perfume of stale fish-baskets is decidedly disagreeable. Thus it is advisable for the person who travels to the isles during the mackerel season to take a robust stomach with him; and to be heartily unconscious of bad smells. On these conditions, there is much to enjoy in the little trip of three or four hours. The Cornish coast is viewed panoramically, and for the brief interval during which one is out of sight of land it is as if one were in mid-passage between Liverpool and New York.

Very soon, however, the low rocks of the isles lift their heads above the