about 240,000 years ago, and extending to about 80,000 years ago. The whole question is argued in Mr. Croll's book, "Climate and Time," pp. 311-328; and he considers the facts of geology to be consistent with the glacial epoch not dating back beyond 80,000 years. Reasoning after his manner, it may be inferred that the mean thickness of stratified rocks has been greatly over-stated. Their maximum thickness of 72,000 feet in Great Britain must not be taken for their mean thickness. "Had the materials been spread over the entire ocean bed, the formation would have had a mean thickness of little more than 200 feet; and spread over the entire surface of the globe would form a stratum of scarcely 150 feet in thickness." 1

A change in the obliquity of the ecliptic would alter the level of the sea. As to the last elevation, it seems almost certain that 11,700 years ago the general sea-level on the northern hemisphere was higher than at present, that was the period of the 25-foot beach; and 60,000 years, the age of the 40-foot beach.2

The alternate warm and cold periods, in north and south, during the glacial epoch, explain the distribution of many plants and animals. As the cold became intense, they would invade the equatorial lowlands; and the inhabitants of these would migrate to the tropical and sub-tropical regions of the south, the southern hemisphere being at this period warmer. On the decline of the glacial epoch, as both hemispheres regained their former temperature, animals and plants again changed places-those not able to do so would die. Warm zones, whether of land or sea, being almost equivalent to life, it is evident that the growth and distribution of plant and animal life are not wholly due to evolution, but rather to climatic agents. Every planet, for a certain long period, presents more of its northern than of the southern hemisphere to the sun at the time of nearest approach; and then, during a like period, presents more of its southern than of the northern hemisphere. Summers and winters are more or less contrasted as the eccentricity of orbit increases and decreases, "Climate and Time," p. 366: James Croll.

Ibid, pp. 407-409.

having the least and greatest eccentricity one or two millions of years apart. To all this there is a response in the changed functions of living creatures, and in the perpetual ebbings and flowings of species. By slow, inevitable change, by elevation and subsidence of land, every climate is altered; every habitat of life is, in turn, destroyed and made new again. Parts, at one time thickly peopled, at another are deserted. The result is, every extensive region has its own meteorologic conditions, and every locality in these regions differs more or less in its structure, in its contour, in its soil. Southern animals lived in our own land during the warm periods of the glacial epoch, and northern animals during the cold; the alternate successions of warm and cold periods bringing about the successive deposits, and leaving in those sediments relics of varying organisms. A surface would remain without seed. or germ for many ages, afterward life abounded; and when the ice-sheet was again spread, everything animate and inanimate was ground to powder.

Notwithstanding these statements by physicists, it is doubtful whether there were any other than mountain glaciers previous to the great glacial epoch; many geological facts evidence a former warm climate extending over the whole globe. Naturalists and palæontologists and geologists of reputation, and who have searched Nature, decide against the former glacialisation of the tropics, sub-tropics, and even of much of the temperate zones. It is perfectly well known that before the glacial periods of the north and south high latitudes, a tropical and sub-tropical flora and fauna existed where they do now, and that these, having a vast ancestry, still remain. Again, as to the vast collections of strata which underlie those of the glacial period in Europe, there is no trace of a general similar condition. There are remarkable deposits in South Africa and in Hindustan, which some geologists attribute to ice-carrying, and to which other geologists just as strongly deny any such origin. In whichever way the question may be settled, the history of our earth shows the work of a "consummate strategist; who, from his mount of observation, directs the movements of a great army, nowhere setting at nought the laws of energy, but exhibiting

and enforcing those laws in delicate, beautiful, marvellous, victorious operations."

The manifold facts, thus studied in rudiments of the world, are a manifestation of energy underlying all the phenomena, and extending to an infinity of worlds in variety of operation and mystery of life. Everything is rooted in the transcendental. There is a continual passing from movement to repose, which is not final rest; a ceaseless oscillation from life to death, from death to life; the order of physical phenomena, like the order of mental phenomena, is inscrutable, flowing from a past eternity into a future eternity. Is this vastness or incomprehensibleness of Nature, a reason for relinquishing the study? Certainly not. "What can be a stronger stimulus to the zealous exercise of our best powers, than the conviction that though we may never be able to attain to 'absolute' truth, yet we can be for ever approaching to it, ever striving upwards so as either ourselves to reach, or to help our successors to reach, a still loftier elevation whence a yet more comprehensive view may be obtained. Tendre à la perfection sans jamais y pretendre' will ever be the animating spirit of the genuine philosopher, as the 'forgetting of things behind, and reaching forth unto the things before,' of the greatest of Christian Apostles, will continue to the end of time to nerve the efforts of every true aspirant after moral excellence." 1 The continual effort of the creature to know the, at present, unknowable reality, is a conscious seeking after fulness of life. As if to encourage that seeking, an All-sustaining Power is everywhere manifested in the existence and phenomenal activity of the universe, who is alike the cause of all and essence of all, without whom the world would not be even the shadow of a vision, for thought itself would vanish. Beyond His infinitude can nothing extend, before or after His eternity can nothing be conceived. The knowledge of His essential existence is that to which the nature of things and the course of time conduct us. How we, the imperfect, are united to the Perfect, and things temporal to the Eternal, human eye cannot It is a mystery hidden within the depths of Divine essence, as is the union of mind and matter; but we know

see.

"Mental Physiology," p. 412: Dr. W. B. Carpenter.

Astronomic Realities.

95

that dependent beings cannot be the authors of their own existence. Their origin is to be found in the will and power of the Independent and Perfect. The universe cannot be regarded as an enclosure, nor infinitude as an extension, nor time as a limitation, of the Eternal. The repetition of organisms in time and space, the course of ages and series of expanse, the number of metamorphoses and progress of evolution, are practically infinite and eternal, to reflect the perfection of their Author. The infinite series of advancing conditions is expressed by Leibnitz in a mathematical symbol, the hypothesis of the hyperbole. We conceive for every given state of the universe a preceding less perfect state. Nothing hinders the supposition, and we give it endless extension; yet, all will be contained within the infinity and eternity of God: such a world is the fittest representation of Divine Majesty. With the telescope, we contemplate the magnitude and numberlessness of worlds; with the microscope, we discover life extending beyond life, surpassing all imagination; science declares infinitude in the multitude and delicacy of principles, in the grandeur and number of existences. Time will never fail to conquerors in knowledge, and the regret of Alexander that there were no more worlds to win, will not be ours who always march to new discoveries of intelligence and power.

In conclusion of the study, picture Astronomic Realities. The sun rules a wonderful variety of planets, and a yet more wonderful variety of life. As fuel for his fires, he gathers from out of space, cosmical bodies and all the forces represented by their velocity. These chips in the great workshop of Nature, this dust from the mighty grindstone of the universe, which the artificers, Attraction and Repulsion, have cast aside, are passed through fire that they may quicken and sustain worlds of life. Close round the sun, Mercury flies in dazzling splendour with unmatched velocity; nearer than Mercury, another planet, Venus, in her beauty, alone; Earth, with her one satellite; ruddy Mars, with two attendants; then hundreds of tiny orbs careering, many coming almost within hail of their fellows. Then that wonderful outer family of planets, the least of which exceeds in size the volume of all

the minor planets and asteroids combined. Yet further, the vast globe of Jupiter and symmetrical family of satellites ; more distant, giant Saturn, of ring-system as a shield, and eight primary attendants, the outermost at range of four and a half millions of miles. Then Uranus and Neptune, brother orbs, but wide apart, and so distant from Saturn that the full span of Jupiter's orbit scarcely brings them together. Uranus, and possibly Neptune, rotating from east to west— unlike all other planets-their moons revolving in the same retrograde direction.

Thence, pass through a desert of vast, inconceivable space to those binary, triple, multiple systems, where sun moves round sun with trains of planets and satellites, glorious creations, making God's mansion sparkle with splendour. Separated, star from star, by enormous intervals of black or stippled ground, the intervals themselves open, with revelation of depth and height rich indeed to the imagination. Seen by unaided eye, the glory of many worlds is but a sparklet, or the scintillation of a needle-point. Different orders of vapours, or fluid nebulæ, perhaps first germs of worlds in infinite series of suns and stars; suns that seem to be members of a new system of higher order, stars which have no dominating centre; prove the sky to be more various and complicate than the wisest thought. Cloudlets-gaseous, stellar, irregular, planetary, ring-formed, elliptic; those light forms of the Milky Way, with shapes fixed or variable; governed by unseen mysterious influence-gravity. There, a green star with deep blood-red companion; there, one of orange hue, accompanied by blue or purple satellite; white orbs mingled with red, light or dark, purple, ruby, vermillion; "a casket of variously coloured precious stones."

Our spirit stops at the centre of centres, the centre of creation, the capital of the universe, whence are the laws which govern and uphold all worlds. Who shall describe the throne of might! the palace of splendour! the inner abode of Deity! What line shall measure, what space contain, what time can reckon, the roll, the circle, the vast procession of million clustered suns? No painter can picture, no poet describe, no heart conceive, the grandeur of that source whence flow infinite and eternal streams of goodness!