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of tons of coal, or about eight times the than in the other. It is also well known whole supply of coal supposed to exist in that the line joining the solstices moves the earth.
around the orbit backwards in about 25,000 Much light has been thrown on these 1 years. This is called the precession of the three great problems of geology, viz., equinoxes. Our winter in the northern changes of climate, oscillations of sea-level, hemisphere now occurs when the earth is and the probable age of the earth, by the in perihelion ; but, it will be readily seen, laborious researches of Mr. James Croll, of in about 12,000 years our winter will occur H. M. Geological Survey of Scotland, when the earth is in aphelion, or furthest summarized in his carefully-prepared and from the sun. If, at the same time, eccenable work on Climate and Time,' noted at | tricity should be at its superior limit, the the beginning of this paper. His theory earth would be 8,641,870 miles further from of the secular change of climate is at once the sun than she is in winter at present. beautiful, simple, and complete. He does | The heat received from the sun varies innot claim that all submergences and emer- versely as the square of the distance, and gences can be traced to those agencies would, therefore, be one-fifth less during which have produced changes of climate ; ) the six months of winter than now, and in but he does hold that many can, and, when sụmmer, one fifth greater. It is true, wintaken in connection with the other well ter would be thirty-six days longer than understood causes, the subject is rendered summer, and the less amount of heat refar more intelligible. His theory affords, ceived in winter would be exactly compenat least, some data for estimating geological sated by its greater length, as was shown by time, the results of which entirely agree | Herschel ; so that the total amount of heat with those obtained by Sir William Thom- | received between the two equinoxes would on, Professor Tait, and others, by entirely be the same, whatever might be the eccendifferent methods. He concurs in the view tricity of the orbit. Eccentricity cannot of expressed by Herschel, that the varying itself, therefore, produce any very great eccentricity of the earth's orbit has not | changes of climate. But, while this is the been sufficient in itself to materially affect | case, Mr. Croll clearly shows that great climate; but he shows that, when taken in eccentricity brings into operation a number connection with the precession of the equi of physical agents which do materially noxes, it may have done so indirectly, by affect climate, and which are amply suffibringing into operation physical agents am cient to produce a condition of glaciation ply sufficient to have produced, during one in the hemisphere whose winter occurs in period, a mild, equable climate even in the aphelion, and, at the same time, a perenpolar regions, and, at another time, a con nial spring even in the polar regions of the dition of glaciation extending far into what other hemisphere whose winter occurs in are now known as the temperate zones. perihelion, and, vice versa, during periods
It is well known that the form of the of about 12,000 years each, till eccentricity earth's orbit is elliptical, and that the sun becomes gradually lowered. He thus deoccupies one of the foci ; that, while the scribes the effect that would be produced mean distance of the earth from the sun is on the climate of the cold hennisphere : constant, the orbit, at times, becomes more •The reduction in the amount of heat reelliptical, and again, as at present, more ceived from the sun, owing to its increased nearly approaches a circle. The superior distance, would lower the midwinter temlimit of eccentricity is '0775, and the infe- perature to an enormous extent. In temrior limit 00314. The present limit is perate regions the great portion of the mois'0168 ; so that, assuming the earth's mean ture of the air is at present precipitated in distance to be 91,400,000 miles (which is the form of rain, and the very small pronow shown to be slightly too little), her dis portion which falls as snow disappears in tance, when in perihelion, would be 89,864, the course of a few weeks at most. But, 480, and when in aphelion, 92,934,060, or in the circumstances under consideration, a difference of 3,069,580. But, when ec- the mean winter temperature would be lowcentricity would be at its superior limit, the ered so much below the freezing-point that earth would be no less than 14,2 12,700 what now falls as rain during that season miles nearer the sun in the one position I would then fall as snow. This is not all;
the winters would then not only be colder follows, therefore, under the circumstances than now, but they would also be much which we have been considering, that the longer. ... The lowering of the tempera- | trades from the cold hemisphere would be ture and the lengthening of the winter much stronger than those from the warm. would both tend to the same result, viz. : This would have the effect of withdrawing to increase the amount of snow accumula the equatorial ocean currents from the cold ted during winter; for, other things being hemisphere and turning them into the warm, equal, the larger the snow-accumulating | greatly intensifying the cold of the one and period the greater the accumulation. ... the heat of the other. As regards the absolute amount of heat re The nearness of the sun in perigee ceived, increase of the sun's distance and would have the effect of greatly increasing lengthening of the winter are compensatory, the accumulation of snow. This would but not so in regard to the amount of snow | result as follows: the currents of air from accumulated. The consequence of this the warm to the cold regions would be state of things would be, that at the com- greatly increased; and, evaporation being mencement of the short summer the ground also increased, vast quantities of moisture would be covered with the winter's accumu would be transported to the cold parts, and lation of snow. Again, the presence of so would there be condensed and fall as snow. much snow would lower the summer tem- | The heaviest fall of snow would, therefore, perature, and prevent, to a great extent, the take place in summer ; and, notwithstandmelting of the snow.' This process would ing the nearness of the sun, he would have go on year after year, till the snow of win- | little melting power, because of the fogs ter would not be melted by the heat of the which would be formed, and which would following summer. Exactly opposite effects cut off his rays. These various agents would be produced in the other hemi- would act on each other in such a way as sphere, so that the general result would be to increase the general result; and we canthat one hemisphere would be heated while not wonder that the cold hemisphere would the other would be cooled. This state of become, during long ages, capped with a things would bring into play agencies sheet of ice thousands of feet in thickness, which would cause the deflection of the as was the case in the glacial epoch ; while great ocean currents, greatly intensifying the other hemisphere would enjoy a mild, the general results.
equable climate. As the solstitial points Mr. Croll discusses at great length the would gradually turn around, the contrary effects of ocean currents on climate. He process would commence. The glaciated shows that they are the great distributors of hemisphere would become warm, and the heat over the surface of the globe ; that by warm hemisphere cold, till the ice would carrying the heat from the equatorial re- be all melted from the one, and accumugions to the polar they reduce the mean lated on the other. temperature of the former from 135° to 80°, It follows from this theory that the and raise that of the latter from 83° below glacial epoch was not one continued to zero. In other words, were it not for duration of cold and ice, but must have ocean currents the equator would be 55° consisted of a long succession of alternate warmer than at present, and the poles 83° cold and warm periods of about 12,000 colder, and the globe would be almost en years each, the warm periods of the one tirely uninhabitable. Any very great change, hemisphere corresponding with the cold therefore, in the great equatorial ocean cur periods of the other. There must have rents, so that their heat-distributing waters been a gradual increase of the two extremes would be withdrawn from one hemisphere of temperature till the greatest eccentricity and spread out over the other, must have a was attained, and then a gradual decline wonderful influence on climate.
till the normal condition of things was again It is further shown that ocean currents reached. That there was this succession of are due to, and take the general direction cold and warm periods in the glacial epoch, of, the prevailing winds of the globe, and there is considerable evidence; though, chiefly of the trades. The trade-winds are from the nature of the case, we know there caused by the difference between the tem- would be, to a great extent, an obliteration 'perature of the equator and the poles. It of the evidences of former glacial periods, and the indications of the last would be | centre of gravity would be shisted 1,000 most clearly marked. We have, here, an feet south, or 500 feet south of its mean explanation of the hitherto perplexing prob- | position, which would cause a total oscillalem of the occurrence in the same beds tion of sea-level to the extent of about 1,000 of the post-tertiary period, of the remains of feet. Again, the weight of the water thus mollusca and maminalia of a tropical type pulled over from one heinisphere to the with those of an extremely arctic character. I other, would tend to increase the general Particularly in England is this the case. | result. But the displacement of the centre We find the lion, the tiger, the hyena, the of gravity must have been much greater elephant, and the rhinoceros associated than 500 feet on either side of its main with the ermine, the reindeer, and the musk- position ; for, during glaciation, the ice-cap ox. The one class lived during the warm must have been of enormous thickness. period, and the other, during the closely | This will be more readily conceded from following cold period.
the following considerations. From calcuSuch epochs of alternate cold and warm lations based on actual observations, the iceperiods must have often occurred during pasi sheet of the small continent of Greenland is time; as often as great eccentricity. The only supposed to attain a thickness in the inevidences that we could reasonably expect terior of 10,000 feet. The southern hemithese cold periods to have left us are trans- sphere is known to be much colder at the ported boulders. These, however, are suf- / present time than the northern, and the ficient, as we know of no agency that could land surrounding the pole, of vast extent, produce such a result but ice. Transported about 28,000 miles in diameter. From reboulders are found in almost every age of liable calculations, the antartic ice-cap is geological time.
estimated to attain a thickness, at or near This theory affords a beautiful explana- | the pole, of at least six miles. During the tion of the coal formations; for we have, / glacial epoch, when the whole hemisphere in the warm inter-glacial periods, the very was capped with ice down to at least the condition of climate best suited to the fiftieth parallel, the flow of the ice, which growth of those kinds of trees and plants of has left so many prodigious results, could which our coal is, composed; as we have, only have been caused by the pressure of also, in the following cold periods, a condi- | its great thickness, and could only take the tion of things best suited to the preservation general direction of the equator, being the of those plants, and their conversion into direction of least resistance. How enorcoal. Wherever we find evidence of gla- | mous, then, must have been the thickness ciation, we also find evidence of submergence | in high latitudes of this vast continental of the land along with it. This is a sug- glacier-So thick, that the White Mountains gestive fact. Let us see what bearing Mr. of New Hampshire were not a sufficient Croll's theory has on this point. The obstacle to impede its progress, or even to accumulation of an enormous ice-cap on one deflect it from its course! We have, here, hemisphere, while the other would be free a simple explanation of oscillations of seaof ice, would have the direct effect of shifting | level, which must have occurred as often the centre of gravity of the earth. If the as glaciation. If coal be an inter-glacial ice-cap, say of the northern hemisphere, formation, as is contended, we can readily had' a thickness equal in weight to 1,000 | understand how it was that coal pericds feet of rock, the centre of gravity would be were always followed by submergence. shifted 500 feet north. The waters of the This explanation, taken in connection with oceans adjust themselves with direct refer- the other well understood causes of subence to the centre of gravity. They would, mergence, tends greatly to remove the mystherefore, flow from the southern hemi- tery that has hitherto attached to the second sphere, so that there would be an emergence great problem of geology. of the land to the extent of 500 feet; and If the intense cold which gives chåracter they would rise on the northern hemisphere to the glacial epoch, has been caused into the same extent, wherever there were directly by great eccentricity of the earth's openings in the ice, and cause a submer-orbit, we have a means of ascertaining gence. When the ice-cap would be trans- with tolerable accurancy the date of its comferred to the southern hemisphere, the I mencement, and the length of its duration.. This gives at least one time-measure with climate of each hemisphere was alternately which to approach the third problem dis warm and cold for periods of about 12,000 cussed in this paper, viz., the probable age years each. Sir Charles Lyell dated the of the earth.
glacial epoch at 1,000,000 years back. If, According to formulæ given by M. Le then, Mr. Croll's theory be correct, and it verrier, Mr. Croll has made calculations ex- | is being rapidly accepted by those best able tending over three millions of years past. He to judge, Lyell's estimate must be reduced finds that eccentricity attained very high by four-fifths of its amount. If we reduce values during three distinct periods of that his entire estimate in the same proportion, time : the first, about 2,500,000 years back; we have 48,000,000 of years, instead of the second, 850,000 years ago; and the 240,000,000, as the age of the earliest third, about 200,000 years ago. The first fossiliferous rocks. Even this reduced and second periods lasted for about 200,000 amount is, in all probability, vastly too years each ; and the third, for 160,000, great. Having obtained, however, with from 240,000 years ago to about 80,000 tolerable accuracy, the date of the last great years ago. For sufficient reasons the glacial geological epoch, and, it may be also, of epoch is assigned to the last period, and the Miocene and Eocene.periods, we may the middle of the Miocene and Eocene venture the hope, that science will yet disages, to the other two respectively. The cover, within reasonable limits, the probable glacial epoch, therefore, lasted for about age of the earth. 160,000 years, during which time the !
S. H. JANES.
FTER an absence of ten years, I re- These provinces ten years since were dis. A turned to Canada early this summer, | united, knowing little of each other, and at Niagara, and have since travelled through having no sympathies or interests in comit from west to east. I have crossed the mon. Suffering from the revolution in broad fertile plains of Ontario, lived among | commerce caused by the abrogation of the the quaint old-fashioned homesteads of Reciprocity Treaty, many turned their Quebec, roamed the pleasant valleys and eyes longingly across the border, sighing skirted the rugged iron-bound shores of for annexation, and showing little faith in Acadia ; and during my progress, I have the success of the scheme of union which been naturally led to speculate on the was then about to be tested. future condition of the country and the How different do we find it to-day ? destiny of its people. I have travelled The country united, and proud of its unity; slowly, making Toronto, Montreal, Quebec, | its people showing a confidence in their St John, and Halifax, my headquarters at future, recovered from the blow that Amervarious times. I have taken advantage of | ican spleen dealt her commerce, and demy opportunities to visit all the surround- termined in the future not to allow theming places of interest, and to mix among selves to be made the sport of their cousins and endeavour to gain a thorough know- across the border. Yes! the scattered provledge of the social and political condition inces of ten years ago, to-day form the of the people, and I consider that I have nucleus of a mighty nation ; their people been amply rewarded for my trouble, in looking forward to the day, in the not noting the immense progress that has been far-distant future, when they will be called made in wealth and in political unity during upon to take their stund among the nations the last decade.
of the earth, and proud to be called Cana have too many politicians and too few dians.
statesmen.' The progress of this spirit must be much I interrupted him to ask him to favor me more evident to one who has been so long with his definition of politicians and statesabsent from the country, than to those who men. have remained at home ; but it must, I “A politician,' he replied, is one who think, have made itself apparent to every | will take advantage of any differences of thinking man. As I before remarked, I creed, sect, and nationality ; who will inhave endeavoured to make myself ac flame the prejudices of the people, and quainted with the sympathies and aspira- | carry partisan feelings to any extreme, to tions of the people, by passing my days further his own selfish ends, or to benefit amongst them, and entering with them into his party. A statesman, on the contrary, the ordinary intercourse of every-day life; ! is one who will strive to harmonize all difand I have found that, in all the different pro ferences between the different classes, for vinces, especially among the young men the interest of the state. The policy of the (who must rule this country in a few years), | one is expediency, and he looks for an imthere is a widespread feeling in favor mediate reward in the shape of the spoils of independence. To give you an idea of of office ; the policy of the other patriotism, the people I have met, I cannot do better and he is satisfied with the gratitude of genthan relate a little incident that happened erations yet unborn.' in Montreal.
‘But,' I said, it must be evident to you One beautiful day, last August, I had that it is a task of infinite magnitude to wended my way to the mountain, and ta unite under one nationality, elements so king advantage of the cool shade of the trees, discordant as the French Catholics of QueI lay idly smoking a cigar. The city was bec and the English and Scotch Protesspread at my feet, the towers of Notre Dame / tants of Ontario, who are not only of difrising like sentinels above it, while the royal ferent blood, but what is often of more St. Lawrence stretched away like a silvery consequence, are each violently prejudiced serpent, as far as the eye could reach. against the religion of the other.
It was on such a day and under such “And why is it so ? 'he exclaimed; they circumstances, when my thoughts were as are all Canadians, and but for the intrigues far from politics as heaven is from hades, 1 of petty politicians would be thoroughthat I was disturbed by a young man of ly united at the present day. The cause perhaps twenty-five or thirty summers, who | which I have at heart,' he continued warmly, wandered through the woods, and appa- 'is one too sacred and too delicate for the rently without seeing me, threw himself vulgar politician ; it is one which requires down on a little hillock, close beside me, the master hand of a statesman. The cause and gazing at the beautiful prospect spread is ripening, but it needs an apostle ; the before us, was soon lost in thought. I ven- people are preparing, but we want the Man.' tured to disturb him, and after a few re I told him that I thought his ideas were marks on surrounding objects, we insensi very far advanced, and that while I might bly glided into a discussion on the state of merely be inclined to consider him an enthe country, and as he seemed to be intelli- | thusiast, others would perhaps think him gent and well-read, I asked him to give me
disloyal. his idea of the present state of things, and | 'I am no farther advanced,' he replied, what he thought of the political future. 'than thousands of my fellow-countrymen ;
We have,' he answered, one of the and,' he added proudly, I think our first fairest and most diversified countries in loyalty is due to ourselves. It is very well which God ever deigned to lay the founda- to talk of loyalty to a country three thoutions of an empire ; but we are unfortunately sand miles away, to which we are only a dependency, and our people lack that bound by traditional ties, and towards spirit of nationality which is the character- whom almost one half of our people have istic of the poorest free and independent no ties, even of blood ; but we must constate. Another great misfortune, and one sider what is best for our own country, and which must greatly retard our progress to- | not be influenced by any sentimer.tal ideas wards independence, is the fact that wel of loyalty towards England. Our task may