Edwin Sharpe Grew

“ The Moon is therefore one of the younger members of the Solar System. But no other catastrophe, either before or since, has occurred on the earth to compare with its prodigious birth. Five thousand million cubic miles of material left the earth's surface never again to return to it. Whether it all left at once or whether the action was prolonged we do not know, but we may try in vain to imagine the awful uproar and fearful volcanic phenomena exhibited when a planet was cleft in twain and a new moon was born into the Solar System. ”

“ The fiery mist would be giving out heat all about it, sending out heat-waves as a fire or a red-hot poker will do. The red-hot poker cools; so, too, would the fiery nebula. Then the nebula would begin to condense; not quite in the same way that a cloud of steam does, for it would be whirling all the time, and its fiery particles would be all trying to fall inwards, just as anything dropped from our hands tends to fall towards the centre of the earth. As this whirling mass of gas condensed some great masses of it would become detached, and would begin to enjoy separate existences of their own. ”

“ After the time when the great overflows of lava took place, spreading over continents and sometimes seas, there was an era when the explosions and outbursts began to diminish in violence, and the world slowly settled down to conditions something like those which we see in our own day. The seas were forming; there was rainfall and summer and winter on the earth. The rains and the winds, the summer heats and winter snows were more violent than now, and the volcanic activity of which we have spoken was much more fierce than anything of which mankind has any recollection. ”

“ It is naturally painful to conclude that the Moon is and always has been deprived of those features of existence which we deem the nobler; that it has never known the stir of air or water or the higher life of beings who inherit the profit of experience, and thereby climb the way that has led upward to man. That these large gifts have been denied to the nearest companion of the earth has its lesson for the naturalist. ”

“ But man's mind and will have enabled him to cross rivers and oceans by rafts and boats, to clothe himself against cold, to shelter himself from heat and rain, to prepare an endless variety of food by fire, and to increase and multiply as no other animal without change of form, and without submitting to the terrible axe of selection wielded by ruthless circumstance over all other living things on this globe. ”

“ How great that pull is may be dimly gathered from the reflection that though the earth is spinning at the rate of a thousand miles an hour, nothing is ever shaken off. The oceans are not shaken off. They cling. But why is it that they are not equally distributed all over the face of the earth? If a map of the earth be examined, or still better a globe with the oceans and continents correctly drawn on it, it will be found that there is a great mass of land all lying grouped together on one side of the earth, and a great basin of waters on the other. ”

“ If the labour of the geologist were concerned merely with the former changes of the earth's surface—how sea and land have changed places, how rivers have altered their courses, how valleys have been dug out, and how mountains have been carved, how plains have been spread out, and how all these things have been written on the framework of the earth—he would still feel one very great want, the want of living interest. ”

“ But we are on firmer footing when we come to deal with that portion of the globe which we can examine. The crust of the earth has been found to consist of successive layers of rock which, though far from constant in their occurrence, and though often broken and crumpled by subsequent disturbances, have been recognised over a large portion of the globe. They are the earth's own chronicle of its history. Had these rocks of the Geological Record remained in their original positions we should have known little of them, because only the most recent would have been visible. ”

“ Now when there is a depression in the barometer that means that the weight of air above the barometer is less than it was before, though it is not so great a difference that human beings could tell it, unless it were accompanied by other signs. But the earth can tell it, and the mere fall of the barometer, owing to changes of the air, will make the earth tremble or quiver slightly, as if it were a jelly. We cannot perceive it; but the delicate seismometers can; and when a storm is coming to Japan or to California from the Pacific, the instruments show that the earth feels the passage of it. ”

“ Earthquake waves start out from the great area where the cataclysm took place, and begin to disturb the earth in all directions, just as if we were to put a row of marbles on a table and were to strike the end marble of the row. ”

“ For millions of years the winds have blown over the surface of the earth, the rain has fallen on it, the sun heated it by day, the frost cracked it. Consider the winds that have circled the earth. All movements of the air are due in the first place to the sun which heats the atmosphere and causes it to expand. The sun's rays passing through the air do not heat it at once, or directly, but heat the land and the sea, which absorb some of the rays and reflect others and so warm the air in contact with them. ”

“ Great parts of Asia and of Africa and of South America remain to be explored, and they may in some future generation fill the gaps of our knowledge and render superfluous some of the divisions which geologists now place in the eras of the rocks and of the fossils. But so far as we know at present there were real breaks in the history of the continents, perhaps not swift or sudden, but wholly changing the appearance and the life, vegetable and animal, of half a world, perhaps the whole world at a time. Many geologists believe that the secret of these changes lies in the core of the earth ”

“ Every one has heard of coral reefs. They are one of the best and most familiar examples of the way in which great masses of solid rock can be built up by the dead bodies of animals. In the warmer seas of the earth, and notably in the track of the great ocean currents, various kinds of coral polyps, as they are called, take root on the edges and summits of submerged rocks and peaks, as well -64- as on the shelving shores of islands. The coral polyp is a jelly-like creature, but it has a hard chalky skeleton inside its transparent body. ”

“ Let us, however, consider what the eye and the telescope will reveal to us. The eye will see the Sun—a great ball, into which the earth might sink without greatly altering the Sun's appearance, and surrounded with flaming gases hotter than the hottest furnace man has ever been able to contrive. In that heat every solid thing on the earth would melt and be turned into vapour. The eye will also perceive the Moon—another ball, much smaller than the earth, surrounded by no gases at all, having as far as can be seen no water ”

“ We do not think of the earth as a very warm body. But at its very coldest part, where the thermometer goes down to seventy or ninety degrees -68- below freezing, it is several hundreds of degrees warmer than the space outside the earth. Midway between the earth and the moon the temperature must be 430° F. below freezing; so that if we take the surface of the earth as a whole we may say that it is between four hundred and five hundred degrees warmer than the space by which it is surrounded. Every one knows what is happening when he warms his hands at a fire. ”

“ We can only imagine what does happen by stating what does not happen. It used to be supposed as late as half a century ago that the earth consisted of a crust of hard rocks perhaps thirty to fifty miles in thickness, and that below this crust the whole earth was a mass of red-hot or white-hot molten stuff with flaming gases mixed with it. If that were the case it would explain a good deal of what we see around us. It would explain the volcanoes, for instance, which belch out fire and lava and ashes and molten rock, and sometimes great fragments of rock. ”

“ People find themselves suddenly thrown to the earth, the ground swept from under their feet. Sometimes the rolling waves of earth are absent, and the movement is a rude quiver, rapidly vibrating in every direction—twisting, contorting, wrenching the ground as if in a determined effort to shake it into dust. Sometimes the most pronounced motion is up and down, as if the earth beneath were being hammered with giant strokes. ”

“ To see how effective the pressure arising from the depths of the ocean may be in driving water into the crust of the earth, we may observe that the tendency to penetrate is everywhere proportional to the depth of the sea. Now everybody knows that if a cistern be placed at the top of a house and connected with a fountain in the garden the fountain ought to throw a jet as high as the cistern because water, as the saying goes, always rises to its own level. As a matter of practice the water does not rise so high because of the resistance of the air. ”

“ It is in these silent depths that for uncounted and innumerable years the crust of the earth has been forming and has been growing outwards, while it has been slowly hardening inwards above the fires of its unplumbed interior.
It has been calculated that in a square mile of the ocean down to a depth of one hundred fathoms there exist more than sixteen tons of carbonate of lime in the form of the bones or shells of living animals. A continual fine "snow-storm" of dead chalky animals is therefore falling on to the bottom. ”

“ Of Uranus and Neptune, still farther off, we know very little, and the progress of knowledge concerning them is very slow; but it is more probable that they are in the early stage of development attributed to Jupiter and Saturn than in the solid stage of planets like the earth. So that we may fairly dismiss the probability of the existence of life as we know it on any of them—and neglect incidentally, therefore, any possibility that life could have been carried in a meteorite from them to us. Whether there are other forms of "life" than any we know is a question hardly needing discussion. ”

“ In the Cambrian rocks there is, for the first time, a fair preservation in fossil form of the life of the period. Even here the record is far from complete, but it is an immeasurable advance on the records of previous periods. The most striking thing about this comparatively plentiful appearance of life is that while the animal kingdom is fairly well represented the plant remains are hardly to be recognised at all. Yet there must have been plants if only to feed the animals, and we have very good reasons for believing that the surface of the land was clothed with some form of vegetation. ”

“ On the other hand, there is nothing in known meteorites to suggest that they came from worlds where conditions exist suitable for life as we know it; and, moreover, even if we shut our eyes to these improbabilities, we are no nearer to a solution of the problem of where and how life began. To say that it was brought to earth on a meteorite is merely to throw back the problem another stage, for we have still to ask how life began on the meteorite and on the planet from which it came. ”

“ A sheet of glass or of marble we usually regard as a thing that may break but does not bend. But all of us have seen glass strips, if they are long enough, bend under their own weight; and there are even marble mantelpieces which, if examined, show that the slab of marble has bent. Thus we can readily imagine that sometimes the strata of the earth will bend by reason of the weight put upon them. If that weight is not put on them quite evenly the strata will be still more likely to bend; it will go from bending to buckling, and from buckling to breaking. ”

“ Sir Archibald Geikie says that the western margin of the ice-fields from the south-west of Ireland to the North Cape of Norway must have presented a vast wall of ice 1200 to 1500 miles long and hundreds of feet high—like that great barrier which the Antarctic explorers tell us frown on the waters that lap the boundaries of the south polar land. Northern Europe must have been like North Greenland of to-day. ”

“ The eye can also see a myriad of stars of varying brightness, but for the most part only thus distinguishable. If the telescope be now called in to aid, the eye will, however, be able to discern differences and distinctions -91- in the stars. It will see that some are balls like the Earth, the Sun, and the Moon. If these balls are studied attentively we shall discover that one of them, Jupiter, is a great deal hotter than the earth, though a great deal cooler than the Sun; and that another of them, Mars, is a great deal colder than the earth, but a great deal warmer than the Moon. ”

“ It was the combination of these lofty trees with the undergrowth of smaller vegetation which formed the forests of the Carboniferous period. "What could be more surprising," exclaims Figuier, "than the -223- aspect of this exuberant vegetation, these immense trees, these elegant arborescent ferns with airy foliage, fine cut, like delicate lace. Nothing at the present day can convey to us an idea of the prodigious and immense extent of never-changing verdure which clothed the earth, from pole to pole, under the high temperature which everywhere prevailed over the whole terrestrial globe. ”

“ There are, at any rate, some of the conditions to support and perhaps to encourage life; and if we could be certain that the atmosphere in Mars more nearly resembles that of the earth, and that its temperature was such as to be sometimes above that of our Arctic regions, then it would be difficult to deny that life, and probably intelligent beings, existed there. One very able and intelligent astronomer is convinced that life and intelligent beings do exist there. ”

“ Meteorites are masses of cooled rock flying through space which still occasionally fall on the earth, and specimens of them are still to be found, many of them preserved in museums, such as the Natural History Museum in Cromwell Road, London. But the earth in its path has swept most of them up, as the housemaid's dusting-pan collects the fragments of dust. When the earth was young there were incomparably more fragments to collect, and they fell on the earth like rain. ”