Popular Science Monthly/Volume 41/May 1892/Why We Should Teach Geology
|WHY WE SHOULD TEACH GEOLOGY.|
By Prof. ALPHEUS S. PACKARD.
APROPOS of a recent article in The Popular Science Monthly, entitled "Do we teach Geology?" it may be said that, while the science may be taught in some high schools and smaller colleges in the one-sided and perfunctory manner stated, the statements under this head seem somewhat sweeping, as is also the writer's condemnation of all of our text-books; those of Dana, of Le Conte, or Geikie, being comprehensive and excellent. The subject should be taught in our universities and larger colleges, so as to train good teachers in the best field and laboratory methods, who should follow such methods when called to teach in the high schools and smaller colleges. Undoubtedly the best way to teach geology is by lectures, supplemented by text-book study, and the collateral reading of monographs, but especially by required field work, and, when mineralogy and lithology are included, by laboratory work. The teacher should have traveled widely, and seen for himself volcanoes and geysers; should have climbed mountain-peaks, visited canons, and examined the effects of erosion, and the every-day work of streams, of waves, tides, and ocean currents. He should show his class by what agencies the scenery at home has been produced, how certain mountains have been carved out of blocks of sedimentary rocks, and, if he lives in a region of fossiliferous rocks, the student should be taught to collect and identify fossils.
All this is done with more or less thoroughness in our better equipped colleges, and where it is possible there are chairs of mineralogy and lithology, apart from geology proper, with well-appointed laboratories and collections, as well as special instruction in paleontology, given by experts; while trained assistants in dynamical geology take classes out for field observation.
But, however the work of instruction be performed, the grand outlines of the study should be impressed on the mind of the student, and the teacher should have a philosophic grasp of the subject; and it is on account of the philosophic and general bearings of geology that it should form a conspicuous element in any liberal curriculum.
Geology, then, in its broadest scope should be taught in our schools and colleges, and for at least twelve good reasons.
At the outset we would claim that it holds equal rank with astronomy or biology. The former science tells us of the existence of other worlds than ours, and gives us some conception of the immensity of space. The study of plants and animals carries an impressive lesson as to the unity prevailing amid all the diversity of Nature, besides affording the hope that we may at some time discover the origin of life, since it has already opened the way to an explanation of the origin of the existing forms of life; while the grand outcome of geological study is that it brings vividly before the mind the immensity of time, enabling us to realize that time is only less than eternity. It also teaches us that our earth has had a history, that our own race has had a high antiquity; and thus the contemplation of past geological ages, reckoned by millions of years, the fact that our earth is coeval with the sun in age—all these considerations tend to immeasurably expand our mental horizon, and thus to react in a way to broaden the mind.
Geology is also the complement of biology. As soon as one has mastered the rudiments of botany and zoology, and of the distribution of life-forms in space, the range of his thoughts should be extended to take in the orderly succession of life in past ages, and the evolution of modern specialized plants and animals from the earlier, generalized types. No liberally educated person can, then, afford to ignore the study, and it seems to us that it should be taken up for the following, among many other considerations:
1. Our first reason is that geology throws light on the origin of our earth and of the solar system in general; the facts and speculations which culminated in the modern nebular hypothesis give some idea of the steps by which our planet assumed its present form and became adapted for the maintenance of life.
2. After the earth cooled down and assumed its present shape and size; in some way unknown to us, monads and bacteria, together with infusoria, one-celled plants and animals, began to exist, and geology hints that the period when all this became possible may have been the early Laurentian, or at least at the dawn of what, for a better name, we call archsean time.
3. We now feel quite sure that the diversity of life of the Cambrian period must have been in some way the result of great changes in the physical geography of that time, and correlated with the inequalities of the sea-bottom, with regions of shallows and of abysses, with landlocked areas, islands, and incipient continents, rising from submarine plateaus bearing mountain-chains. Geology describes the birth of continents, the rise of mountain-chains, and discusses the results of the action of heat in transforming the physical features of our globe, and thus, in part at least, explains the origin of volcanoes, the causes of earthquakes, and the processes of mountain-carving, through the agency of brooks and rivers.
4. Over immense tracts of mountainous regions, rocks, originally stratified, and packed with, the remains of living beings, have been transformed into slates, schists, and other crystalline rocks, and the inquiry, how this has been done, can only be answered by the geologist.
5. During the process of mountain-building the earth's crust has been uplifted, shattered, or dislocated, and finally permeated by hot springs, and the cracks and rents extending to the surface filled with the precious minerals. Certainly there is good reason why we should know how the ores thus came to be brought up from the bowels of the earth and almost laid at our doors. Theoretical geology gives us the probable explanation.
6. Our North American continent has had a beginning, has passed through a period of infancy, youth, and maturity; the mountain-ranges bounding it are of different ages; its varying climates have become gradually established, and at different epochs it was fitted for the maintenance of quite different assemblages of plants and animals. The intimate relationship between these successive plant and animal worlds and the ground on which they were born, flourished, and died is now tolerably well understood by our geologists.
7. Coal and coal-oils are geological products. Geologists can now give a satisfactory account of just how coal-beds have been formed from vast peat swamps; why great beds of iron ore are interstratified with the coal. We have only had our attention drawn to coal-oils since 1860, but already our geologists feel confident that they are due to the immense profusion of marine animals or vegetables, or both, during the times before and since the great Coal period; and chemical geologists nearly all agree in believing that petroleum is due to the storage in the earth of the chemical products derived from the tissues and oily matters once forming part of the bodies of myriads of living beings.
8. It is interesting to know, and history-classes learn, the mode of origin of the people of Greece, of Rome, of the making of Great Britain, the mode of origin of the French or German peoples, and the successive steps in the history of our own nation. It is equally important to know when the worms, ascidians, early vertebrates, and fishes made their appearance; when it became possible for air-breathing vertebrates to exist, and when the forerunners of mammals and man, the amphibians, were evolved from the ganoids. Paleontology throws light on these points, if intelligently studied and properly taught.
9. Much time is given in our schools to the memorizing of the dates of the birth and death of kings and of dynasties. Why should not the pupil also learn the geological date of the first known appearance of mollusks, star-fishes, worms, insects, fishes, reptiles, birds, and beasts? There are a great many isolated facts and dry details in the study of fossils; but the leading conclusions, particularly those treating of the elaboration of the lines of forms resulting in the modern horse, the ox, the camel, and our other domestic animals, can be made interesting, and indeed juicy and palatable, to the bright boy or girl of fifteen, or to the college student.
10. The discovery of a single ammonite enabled the geologist to determine the geological age of the gold-bearing rocks of California. How indispensable fossils are as time-marks, characterizing the different formations, and the immediate practical use of such facts to the mining prospector, always interest a geological class.
11. If, as is not improbable, man was evolved from some lemurlike form, and pursued a line of development parallel to, but immensely surpassing, that followed by the lines culminating in the monkeys and apes, it is a matter of deep interest to learn the probable time when vertebrate animals in which the fore legs were used for climbing appeared; when such was the struggle for existence that the ordinary mammalian equipment did not suffice, and the brain was called upon to act more immediately, the limbs and skull being remolded, in a way before unknown, to answer the behests of growing intellectual powers, until man as man appeared. Paleontology again must be invoked, and who knows how soon, when we learn more of the later Tertiaries of Africa and Madagascar, light may flash forth and illuminate this dark problem!
12. One of the triumphs of modern geology is that it has established the fact of the high antiquity of man; that it has brought forth out of caves and gravel-beds the man of Neanderthal, the man of Spy, the inhabitants of the caves and shelters of central France and of southern England; and told us what manner of men they were, what weapons they used, the nature of their dwellings, of their clothing, their art instincts, their cuisine, and something of their religious aspirations, as shown in the burial of their dead. It is those antiquarians and geologists who began with the study of zoology and of geology who have founded anthropology, the youngest of the sciences. It is thus due to the geologist that the old science of ethnology has been rehabilitated—in fact, rejuvenated.
It is owing to the combined labors of geologists and anthropologists that an entirely different view is now taken of the origin of man. It is almost a matter of scientific truth that primitive man was inferior to the lowest of existing savages; that our present Australian and negro races are physically and intellectually, perhaps, on a higher plane than the race of Neanderthal and of Spy; and that there has been a geological succession of human types, leading up to races of which our existing savages are the descendants. Physically, man of the present time is a most composite being, the result of crossings which began to take place long before the dawn of history. And, finally, it has been left for the geologists and archaeologists, of whom Lyell, Lartet, Mortillet, and others, are types, to point out the overlapping of prehistoric upon historic times, and thus to bring to light the lost ages, filling up the abyss in our knowledge formerly existing between the dawn of human history and the close of geological history.
Such is the light which geology has already thrown upon the origin of man, and of the world in which he lives. Who can deny the utility and importance of a study which bears such fruits? How can a person be regarded as liberally educated who has not been brought in contact with these facts? And yet there are still hundreds and thousands of our college graduates who have neither had careful training in the principles, nor have been brought into contact with the grand results of modern geology; whose minds have not felt the inspiration and mental tension resulting from contact with these wonderful discoveries and conclusions. Is there not every reason why geology should be taught, provided the facts and principles be imparted in a way to stimulate, quicken, and expand the mind?