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LECTURES ON COAL.

BY PROFESSOR JOSEPH LE CONTE.

Nature is a book in which are revealed the divine character and mind. Science is the human interpretation of this divine book, human attempts to understand the thoughts and plans of Deity. The book being divine, it is evident that all parts are equally sacred. The subjects of all sciences may be said to be equally, because they are all infinitely, noble. To the scientific mind the organization of an insect, a polyp, or an infusorial animalcule is no less dignified a subject of human inquiry than the organization of the solar system. Yet, as in the Sacred Scriptures, while all parts are equally sacred, because all are divine, some are cherished with peculiar reverence, as giving nobler conceptions of divine character, or clearer views of human duty. So also in science there are some branches which, hy a certain magnitude in the objects with which they deal, strike the imagination and kindle the enthusiasm in a peculiar degree. From a purely abstract or intellectual point of view they may be all equal, but as human stuldies, as means of elevating the mind and ennobling the soul, they differ very much among themselves

In this, the noblest function of science, there are two departments which stand out beyond all others, viz: astronomy and geology. We are all accustomed to look upon astronomy as the most magnificent of sciences, as more than all others extending the bounds of human intellectual vision ; but I am perfectly confident that when the age has grasped as firmly and apprehended as clearly the fundamental idea of geology as it has already done that of astronomy, all will agree with me in thinking that the former is not one whit behind the latter in the overwhelming grandeur of its conceptions. Let us, then, compare these two noble sciences. Let us attempt to vindicate the claims of geology to stand beside astronomy in the very first rank of sciences as twin sisters, distinguished from all others by superior beauty and dignity.

There are two conditions of material existence, viz: space and time, We cannot conceive of material existence except under these two conditions. Now, the peculiar province of astronomy is space, as that of geology is time. Other sciences may have to do with space, limited space, a portion of space, but it belongs to astronomy alone to deal with infinite space. So also there are other sciences which necessarily deal with limited time, but it is the peculiar prerogative of geology to deal with infinite time.* As astromy is limited in time to the present epoch, or, in fact, to about two thousand years, but unlimited in space, so also geology is limited, in space to the surface of the earth, but unlimited in time. As astronomy measures her distances by billions of

* We use the term “ infinite” with reference to time, as with reference to space, as synonymous with inconceirably great, illimitable by human conception,

miles, or millions of earth radii, so geology her epochs by millions of years, i, e., earth revolutions. As the astronomer takes the radius of the earth as a base line wherewith to measure the dimensions of the solar system, so the geologist takes the present geological epoch, and “causes now in operation,” as a time measuring rod, with which to estimate the length of the tertiary period. As the astronomer, becoming more bold as he ascends, takes the diameter of the earth's orbit as a line wherewith to calculate the distances of the fixed stars, or even dares to estimate the probable distance of the remotest nebula, so the geologist, no less daring, takes the tertiary as a rod wherewith to measure approximatively the almost inconceivable lapse of time represented by the secondary rocks, or even dares to cast his telescopic glance back into the dim nebulosity of the remotest palæozoic period.

Finally, as the astronomer, when telescopic vision fails, still speculates, though filled with awe, concerning the infinite, unknown abyss of space beyond, so also the geologist, when mile-stones are no longer visible, when fossils and stratified rocks fail, still vainly peers with wondering gaze backward, and strives to pierce the darkness beyond, still believes that all he sees, or can ever hope to see, is but a fragment of the infinite abyss of time beyond. Overwhelmed, appalled, he shrinks back within himself, and remembers that his own mind, so daring, so arrogant, so apparently limitless, is also but a fragment of the infinite intelligence.

Thus, while astronomy fills the regions of the universe with objects, geology fills the regions of infinite duration with events. As astronomy carries us upwards by the relations of geometry, geology carries us backwards by the relations of cause and effect. As astronomy steps from point to point of the universe by a chain of triangles, so geology steps from epoch to epoch of the earth's history by a chain of mechanical and organical laws. If one depend on the axioms of geometry, the other depends upon the axioms of causation. In a word, the realm of astronomy is the universe of space, that of geology the universe of time. The one peoples her universe with space-worlds, the other her's with creations-time-worlds.

The great object of all science is to establish the universality of law; harmony in the midst of apparent confusion ; unity in the midst of diversity; unity of force amidst diversity of phenomena, physical science; unity of plan in the midst of diversity of expression, natural science. Now, it is the peculiar province of astronomy to establish this universality of law throughout all space, as it is of geology throughout all time. Astronomy shows that the same force which controls the falling of a stone governs the motions of the heavenly bodies; so also geology shows that the changes through which each animal passes in its embryonic development are similar to those through which the whole earth and its inhabitants have passed in the course of its geological history; that the same mind which now conducts the one has presided through all time over the other. If astronomy, more than all other sciences, illustrates that sublime attribute of Deity, His omnipresence or unchangeableness in space, geology, more than all other sciences, illustrates that other sublime attribute of Deity, His immutability or unchangeableness in time.

There are in the history of science two eras which, more than all others, strike the imagination and fill the mind with admiration. Or rather, I should say, two moments, the greatest in the intellectual history of the human race. They are those in which were born in the mind of man the fundamental ideas of astronomy and geologythe ideas of infinite space and infinite time, containing other worlds and other creations. You have all, probably, thought of the sublimity of that moment when the idea of infinite space, peopled with worlds like our own, was first thoroughly realized by the mind of man. You have all, probably, shared in imagination the exstacy of Galileo as gazing with awe through the first telescope, the phases of Venus and the satellites of Jupiter suddenly revealed to him the existence of other worlds besides his own. Before that pregnant moment our own was alone in the universe. Sun, moon, and stars were but satellites to the earth. Astronomy was but the geometry of the heavens ; the geometry of the curious lines which these " wandering fires traced upon the crystalline concave of the skies. In an instant the great fundamental idea of modern astronomy was born in the mind of Galileo. In an instant man's intellectual vision is infinitely extended, but his own world, before so great, has shrunk into an atom in the midst of infinite space; has become a younger sister, a comparatively insignificant member in a great family of worlds.

We have all been accustomed to look upon this as the grandest moment in the intellectual history of man. But there is another moment less known, or if known, less thought of, because less understood and less appreciated, but not less grand. It is that in which was born in the mind of man the fundamental idea of geology; in which the idea of other time-worlds besides our own entered the mind of the aged Buffon.

For many years, indeed centuries, it had been observed that organic remains, particularly marine shells, might be found far inland, and even high up the slopes of mountains. There was much speculation among scientific men as to the origin of these shells. They were attributed by some to the deluge, by others more truly to gradual and permanent changes in the relative level of sea and Jand. But no one for a moment supposed that they belonged to any period anterior to the present epoch. Some may have supposed that they were extending the known limits of the present epoch, that they were discovering new continents in the ocean of time, but never dreamed that these were the evidences of a new world in the infinite abyss of time. Buffon himself had taken active part in these discussions. Finally, near the end of the last century, and in the evening of his great and long life, a large number of these remains, both marine shells and mammalian vertebrates, larger than he had ever examined before, were placed at his disposal and subject to his inspection. To his astonishment he found them entirely different from species now inhabiting the earth. In that moment, in the mind of the venerable Buffon, suddenly, like Minerva from the head of Jove, was born the idea of infinite time containing successive creations. In an instant man's intellectual vision was again infinitely extended; but his own world again dwindled into a single day in the geological history of the earth.

The whole future of geology was seen in the vision of that moment. Filled with awe, the old man, then over 80 years of age, published his discovery. In a kind of sacred phrenzy he spoke of the magnificence of the prospect, and prophesied of the future glories of this new science, which he was, alas, too old to pursue. Thus, to the last, his dying hand pointed the way, and his dying voice kindled the enthusiasm of those whom he could no longer lead.

Picture for a moment to yourself the aged Buffon thus gazing in rapture, silent and alone, upon this new world suddenly opened to his intellectual vision. I cannot help comparing him to Moses of old on the top of Pisgah. Like Moses, he had reached the extreme verge of mortal life; like him, he stood upon a mount, raised far above the rest of the world by the eminence of his intellectual position; like him, he gazed with sucred solemn joy, mingled with sadness, upon a new world, a promised land, which he was forbidden to enter; and, like him, also, he died there upon the mount, prophesying of the future glories of the new land, and calling upon his followers to enter in and take possession.

One more comparison between these two noble sciences : In comparing modern with ancient or even mediaval civilization, nothing is more striking or more significant than the difference in the manner in which nature is viewed in relation to man. The spirit of the older civilization tended to exalt man in his own estimation and to degrade nature, while that of modern civilization tends to humiliate by insisting upon his insignificance in comparison with the greatness of nature. In art this is seen in the gradual but constant increase in the contemplation of nature, both in painting and poetry. An increasing love of wilderness and mountain, of rock and crag, of cloud and sky. In science it is still more distinctly seen in the amazing progress of the physical and natural sciences. The mind of man has gradually passed from the study and contemplation of itself to the study and contemplation of nature. We believe this was a necessary, but cannot believe that it is a final change. When, by the study of external nature, a true and solid foundation is laid for philosophy, the human mind will again return to the study and contemplation of itself, as the greatest of nature's works.

Now, it has already been seen, that among the most efficient agents in bringing about this great and necessary change have been the sciences of astronomy and geology. Nothing has tended so much to humiliate the pride of man as the recognition of the astounding fact that his habitation, his world, is but an atom among millions of similar atoms in the boundless realms of space; and that his time, the life of his race, is but a day in the immeasurable cycle of geological changes. But there is this great difference between the two sciences, that while astronomy leaves man thus humiliated, prostrate, and hopeless, geology lifts him up and restores him to his dignity. While astronomy gives no evidence of the superiority of the earth to other heavenly bodies, or of man above other possible material intelligences-gives no hint of the superior dignity of our world among other space-worlds-geology most distinctly declares the superior dignity of our time world, and of our race, among all other time

worlds and their races. She teaches unmistakeably that there has been a gradual course of preparation for the present epoch ; that there is an unity of plan in the whole system of time-worlds ; that, in a certain sense, they are all satellites to ours; that they are all bound together by a force ; that force the plans of the Almighty, and its centre the present epoch. Thus man becomes the centre of the universe of time. Thus, also, by analogy we are led to suspect that there may be a similar unity in the system of space-worlds also, and that ours may, and probably does, enjoy a superiority, if not in size at least in organization, and therefore in the intelligence of its inhabitants. Thus man's dignity is restored, or rather, I should say, dignity is given in place of pride. “Pride goeth before a fall,” but digpity comes after.

But it will no doubt be objected by many that the position of a science depends not only upon the dignity of its subjects, but also, in no small degree, upon the certainty of its conclusions, and that, in this respect, astronomy is far superior. But even this is a mistake, the result of misconception. Even here the superiority of astronomy has been very much exaggerated. Astronomy has its hypotheses and uncertainties as well as geology; and, on the other hand, geology has its certainties as well as astronomy; only it has happened, in this as well as in many other cases, that the wisdom of age has given false dignity to its errors and follies, while the wildness of youth has discredited its wisdom. The certainties of astronomy have given an appearance of truth to its wildest hypotheses, while the hypotheses of geology have unjustly thrown some discredit upon her truest theories and most certain facts. The certainties of astronomy are the form, size, weight, distance, and relative position of her space-worlds. Her uncertainties are their physical geography, climate, and, more than all, their inhabitants, animal and vegetable. The certainties of geology are the physical geography, climate, and, more than all, the inhabitants, animal and vegetable, of her time-worlds, while her uncertainties are their relative size and distance. It is seen, then, that the certainties of the one are precisely the uncertainties of the other. Which, then, are the nobler—the certainties of astronomy or those of geology? Is it more noble to know the relative size and position of worlds in space and time or to be acquainted with the beings which form their crowning glory? It would carry me too far to pursue this train of thought. Suffice it to say that, in either case, that which was most important to know has been rendered most certain ; while, also, in both cases, that which is most uncertain is also least important to know.

I have thought this long introduction necessary, because geology is so constantly misunderstood. She is looked upon by some with suspicion, as wild in her speculations and uncertain in her conclusions ; by others with indifference, as a mass of dry and unattractive detail ; and by still others with positive dread, as tending to infidelity. I deemed it necessary, therefore, to say a few words in vindication of her high rank among the inductive sciences, both in respect to the certainty of her conclusions, and, still more, the nobleness of her conceptions and the absorbing interest of her subjects. I might have

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