Jaggar My Experiment with Volcanoes

1. Auflage 2023
ISBN: 978-3-98826-198-4
Verlag: OTB eBook publishing
Format: EPUB
Kopierschutz: 0 - No protection

E-Book, Englisch, 242 Seiten

Reihe: Classics To Go

Excerpt: ?When I was fourteen my father the Reverend Thomas Augustus Jaggar, took our family to Europe, where botany and bird life were as much a part of my education as geography, French, and Italian. And it was during our visit in Italy that I made my first trip up Vesuvius. All of these early interests convinced me that I wanted to be a naturalist. It was Nathaniel Shaler at Harvard who told me to go and study the beaches at Lynn and Nahant. So I walked and photographed, and measured ripplemarks. I found a headland and a longshore accumulation with scallops dwindling regularly along the high-tide level. I found swash marks a foot across forming as the tide went out. On the dunes were other sand waves beautifully regular.

Autoren/Hrsg.

Jaggar, Thomas Augustus

Leseproben

Chapter I
Young Scientist
“The gold of that land is good: there is bdellium and the onyx stone.” It was the training of my youth under a father who loved God’s out-of-doors that led me to Audubon’s birds; to tramping miles over carries in Maine, Labrador, and Nova Scotia; and to fishing with another eight year old, named Willie Grant. When I was fourteen my father the Reverend Thomas Augustus Jaggar, took our family to Europe, where botany and bird life were as much a part of my education as geography, French, and Italian. And it was during our visit in Italy that I made my first trip up Vesuvius. All of these early interests convinced me that I wanted to be a naturalist. It was Nathaniel Shaler at Harvard who told me to go and study the beaches at Lynn and Nahant. So I walked and photographed, and measured ripplemarks. I found a headland and a longshore accumulation with scallops dwindling regularly along the high-tide level. I found swash marks a foot across forming as the tide went out. On the dunes were other sand waves beautifully regular. Try it. Lie on your stomach and watch them. They are at right angles to the wind. Smooth them out and see what the wind does. It piles little flocculent heaps of course grains, each with an eddy downwind. The fine stuff migrates up the slopes forward with the wind, backward on the leeward side. The powder streams meet and lengthen the hills right and left. I watched the swash marks. The swash of the surf full of sand rushed up the beach, cleared suddenly, and retreated, leaving a ridge along the beach. This elevation became the tide limit, and a new series started lower down. The swashes couldn’t climb over the ridge because the tide was going out. And so for hours ridge after ridge was built. I watched high-tide scallops, six feet apart, forming heaps at the top of the beach. The swash waves ran into the bays between the heaps during the flood hours, making a rush up and a suck down. The rush up was muddy, the suck down was clear. Pebbles and sand were building up on the sides of the small promontories. Each heap was horseshoe-shaped, with the toe seaward. Forty or fifty crescents got smaller and more sandy toward the middle of the beach. Here was rhythmic force making repetition. The ripples and swash marks were repeated seaward. Clearly the headland of rock was making pebbles and sand, sending pulsations along the beach, instead of across it. The ripplemarks were packed sand of the low-tide flat, formed totally under water parallel to the waves. The back-and-forth motion of waves made a pattern of sweep and eddy on the bottom. Were beaches, then, things of habit like birds? Here were four kinds of sand waves, all on one beach, all of them complicated by wind and water and tide; big and little; shapely and regular. The beach was alive. It was building from the end, it was rippling under wave action. It fed the wind as it dried, and the wind made an exquisite dune pattern of the grains. Perhaps beaches might be natural history, just as much as the birds that inspired my interest in nature when I was eight years old. The mystery of the beaches drove me to a new discovery; to the university library, where I found French and English references to ripplemarks. I found experiments, soundings, fossil sandstone ripples. I learned that such great authors as the botanist De Candolle and Sir George Darwin had interested themselves profoundly in what happened to the sand grains. From the library I went to mud puddles in a tank and to experimentation. Thus I found my way from beach to books and from books to the making of baby beaches. Later, at Harvard, zoology and botany were all cells and embryos and the microscope. The habits of animals scarcely entered into our studies. The natural history of Audubon and my boyhood had vanished. The new words were phylogeny and cytology, development of the individual, and cell development. So in mineralogy the microscope and the tiny crystal governed; the molecules of the crystal, and the chemical atoms of the molecule. Science was headed toward the infinitely little, though later, by way of the spectroscope, it was to leap to the infinitely big of the heavens. I never learned to think the universe finite. Professor Shaler wrote in 1893, “In the next century there will be a state of science in which the unknown will be conceived as peopled with powers whose existence is justly and necessarily inferred from the knowledge which has been obtained from their manifestations. In other words, it seems to me that the naturalist is most likely to approach the position of the philosophical theologian by paths which at first seemed to lie far apart from his domain.” Just this has happened in the world of galaxies and electrons, producing Einstein and Planck, Jeans and Eddington, Hubble and Hoyle. And I suspect that sea bottoms and volcanoes are “peopled with powers” yet to be inferred. Through Josiah Cooke and his wonders of projection apparatus; through Cook’s nephew Oliver Huntington and his mineral crystals; through John Eliot Wolff, whose assistant in optical microscopy I became; through Robert Jackson with his museum collection technique and the hexagon plates on fossil sea urchins; through all these I was introduced to the laboratory collections and instruments. I found a fascinating world. The theater, too, furthered my education. Like many Harvard students, I “suped” for several great actors and actresses, among them Julia Marlowe and Sarah Bernhardt. And in one play I even had a speaking part: “My lord, Posthumus is without.” I also practiced legerdemain as amateur assistant to Kellar and Hermann, who called me out of the audience and pulled rabbits out of my coat and eggs out of my mouth. Thus I learned of the psychology of audiences, how to experiment in public, and how easily deluded is the average mind. Just so nature may delude, if the scientist doesn’t keep his wits about him. But I also learned the value of vivid demonstration before students. A great exponent of this method of teaching is Professor Hubert Alyea of Princeton. His chemical experimentation is marvellous. His chemistry textbook is modern physical chemistry at its best. He demonstrates that the art of the magician has come down to the twentieth century and that even mathematical science may pass over to the layman. I suspect that geophysics does not need to be buried under differential equations as it is today. Certainly experimental volcanology made exciting at the lecture table could work wonders in getting the globe explored. At Harvard we were taught that geology was a detective history. Vaguely, the same fossils were the same age. Vaguely, man had come from a fish which climbed up on the land. It was much later that radio activity of rocks was accepted as setting ages in millions of years. King and Kelvin taught us that the age of the earth was 24 million years and the sun was dying. A half century later, 2,000 million years was the figure and the sun was heating up. Now cosmogonists talk easily of 10,000 million years as an item in star history. I have learned that one can have any theory he chooses, and that some new discovery will probably reverse it. A discovery is the uncovering of an appealing, bright idea. The idea of geology as history based on Darwin’s evolution never took root in my consciousness. Geology to me is the science of the globe. Science studies how things work, how things change, how they accomplish what they do, how they grow, and how they compare. It does not study the “why,” or the necessity for an origin of anything. Originating is eternally in progress. Astronomy today is giving up origins. History based on a few relics seems futile. Relics, or specimens, must be compared with action. Guessing that we must have come from a fish, with no evolution sequence in successive strata and no mammals whatever in very ancient strata and no preservation of soft creatures possible, seems a contradiction of Darwin’s own testimony. He insisted on “the imperfection of the geological record.” But he had no conception that the Cambrian was 500 million years B.C., nor that the fiery Keewatin of Lake Superior was 1,800 million years B.C. Darwin knew that the bivalve brachiopod Lingula, now alive in quiet seas, is exactly the same today as it was then. Lingula is found fossilized in the intermediate geologic eras. We have no proof that intelligent beings in ships from unknown lands did not dredge him up in Cambrian time. Five hundred million years is so absurdly long that there may have been at least twenty different flowerings of intelligence on the earth, having no relation to us. Continents are places of catastrophe. Sea bottoms are places of constancy. Man lives on continents, and his fossilized bones are short-lived. If each Adam preceded a new humankind of 100,000 years, the time since the Cambrian allows for 5,000 deluges, or eruptive conflagrations. Each one would exterminate that particular Adam’s descendants. If glacial periods are deluges, we know their scratched boulders back to 400 million years before Lingula. These older ice sheets were in Canada. But we know fiery floods of lava 1,300 million years before Lingula, on the north shore of Lake Superior. We have not one particle of evidence that before the race was killed off primordial volcanologists, who were very queer looking chaps, might have studied those eruptions with expensive instruments. Certainly they had a lot of copper at their disposal. Perhaps the great lakes were a continental sea, and some ancestor of Lingula was...