Annals of the Former World

by John McPhee

  Agassiz’s response was to address himself more intensively than ever to glaciers—glaciers of the present and the past. “Since I saw the glaciers I am quite of a snowy humor, and will have the whole surface of the earth covered with ice, and the whole prior creation dead by cold,” he wrote in English to an English geologist. “In fact I am quite satisfied that ice must be taken in every complete explanation of the last changes which occurred at the surface of Europe.” He found moraines on the plains of France. He found Swedish boulders in Germany. In Grindelwald, a stranger heard his name and, seeing his boyish appearance, asked if he was the son of the great and famous professor.

  In 1839, Agassiz went to the glaciers on the apron of the Matterhorn, the glaciers under the Eiger and the Jungfrau. He walked up the Aar Glacier to the base of the Finsteraarhorn, the highest peak in the Bernese Oberland. “There I ascertained the most important fact that I now know concerning the advance of glaciers,” he wrote later. From a message in a bottle in a cabin on the ice, he had learned that the monk who built the place in 1827 had returned nine years later to find it more than two thousand feet down the mountain. Agassiz established his own shelter on the Aar Glacier. He and his colleagues drove stakes into the ice—a row of them straight across the glacier—and before long discovered that glacier ice, like a river, flows more rapidly in the center and also tends to speed up toward the outsides of bends. Diverting a meltwater stream that was pouring into a deep hole in the ice, he set up a sturdy tripod at the surface and had himself lowered into the glacier. He was twenty fathoms down in a banded sapphire world when his feet touched water and he shouted instructions that his descent be stopped. His colleagues on the glacier misinterpreted his cry and lowered him into the water. The next shout was different and was clearly understood. The dripping Agassiz was raised toward the surface among stalactites of Damoclean ice, so big that had they broken they would have killed him. Concluding the experiment, he said, “Unless induced by some powerful scientific motive, I should not advise anyone to follow my example.” The better to see the alpinevalley ice in its regional perspective, Agassiz and his team climbed mountains—they climbed the Jungfrau, the Schreckhorn, the Finsteraarhorn—and made their observations from the summits, completely unmindful atop a number of the mountains that no one had been there before.

  Agassiz went to England, Scotland, Ireland, and Wales, looking for the tracks of glaciers. He found them in England, Scotland, Ireland, and Wales. As in Switzerland, he saw roches moutonnées—humps of exposed bedrock that were characteristically smooth on the side from which the ice had arrived, and plucked and shattered on the other. “The surface of Europe, adorned before by a tropical vegetation and inhabited by troops of large elephants, enormous hippopotami, and gigantic carnivora, was suddenly buried under a vast mantle of ice, covering alike plains, lakes, seas, and plateaus,” he wrote in his Études sur les Glaciers (1840). “Upon the life and movement of a powerful creation fell the silence of death. Springs paused, rivers ceased to flow, the rays of the sun, rising upon this frozen shore (if, indeed, it was reached by them), were met only by the breath of the winter from the north and the thunders of the crevasses as they opened across the surface of this icy sea.”

  The reception all this got continued to be colder than the ice. Von Buch, author of the first geological map of Germany and already celebrated for his studies of volcanism, did not conceal his indignation. In fact, he had apparently removed Agassiz’s name from consideration for a professorial chair at the University of Berlin. Sir Roderick Murchison, the Scottish geologist who had identified and named the Silurian system, warned that he was prepared to “make fight.” Addressing the Geological Society of London, he said, “Once grant to Agassiz that his deepest valleys of Switzerland, such as the enormous Lake of Geneva, were formerly filled with snow and ice, and I see no stopping place. From that hypothesis you may proceed to fill the Baltic and the northern seas, cover southern England and half of Germany and Russia with similar icy sheets, on the surfaces of which all the northern boulders might have been shot off. So long as the greater number of the practical geologists of Europe are opposed to the wide extension of a terrestrial glacial theory, there can be little risk that such a doctrine should take too deep a hold of the mind.”

  Whatever the cause, the effects Agassiz was studying impressed von Humboldt as purely local phenomena. Agassiz’s “descente aux enfers”—into the innards of the glacier—alarmed his friend as a physical risk commensurate with the risk Agassiz was taking with his paleontological reputation. Von Humboldt wrote to say that he had now “read and compared all that has been written for and against the ice-period” and that he was no closer to accepting the theory. He quoted Mme de Sévigné’s saying that “grace from on high comes slowly.” And added, “I especially desire it for the glacial period.”

  The turnabout was at hand, however. Charles Lyell, the most outstanding British geologist of the nineteenth century, closely read the Études sur les Glaciers and found himself enlightened. “Lyell has adopted your theory in toto!!!” a friend wrote to Agassiz. “On my showing him a beautiful cluster of moraines, within two miles of his father’s house, he instantly accepted it, as solving a host of difficulties that have all his life embarrassed him.” Charles Darwin hurried out into the countryside to see for himself if there were “marks left by extinct glaciers.” He wrote to a friend, “I assure you, an extinct volcano could hardly leave more evident traces of its activity and vast powers … . The valley about here and the site of the inn at which I am now writing must once have been covered by at least eight hundred or a thousand feet in thickness of solid ice! Eleven years ago I spent a whole day in the valley where yesterday everything but the ice of the glaciers was palpably clear to me, and I then saw nothing but plain water and bare rock.”

  The scientific dons of Cambridge continued stubborn, but—as would happen with the theory of plate tectonics in the years following the revelations of the nineteen-sixties—geologists in expanding numbers accepted the glacial picture, and before long there was a low percentage that did not enthusiastically subscribe. Delivering an address in 1862 to the Geological Society of London, Sir Roderick Murchison declared without shame that he, too, now saw the picture. He sent a copy of his address to Agassiz with a note that said, “I have had the sincerest pleasure in avowing that I was wrong in opposing as I did your grand and original idea of my native mountains. Yes! I am now convinced that glaciers did descend from the mountains to the plains as they do now in Greenland.”

  Greenland is eighty-five per cent capped with ice. Anyone who doubts that we live in a glacial epoch need only note the great whiteness that Greenland contributes to a map. “The ice melted here eighteen thousand years ago,” Anita said, with a nod toward the roadside in Ohio. “It melted twelve thousand years ago in Wisconsin and Maine. If you ask a penguin in the Antarctic, the Ice Age hasn’t stopped yet.”

  The ice on Antarctica, six million square miles, is also (generally) two miles thick. “You get ice caps when you have landmasses in the polar positions,” Anita went on. “The only thing worse would be if the Siberian landmass were sitting over the North Pole. Then, God help us, things would be really bad. As it is, the sea ice at the North Pole is only six feet thick. It takes a continent to support a really heavy sheet of ice. If the ice of Greenland and Antarctica were to melt now, sea level would go up at least a hundred feet. Think what the water would cover. Half the cities in the world. In the South, you can be three hundred miles from the coast and only fifty feet above sea level. Through most of time, the earth has been without ice caps. Twenty thousand years ago, when there was much more ice than there is now, the sea was three hundred feet lower. The coast was more than a hundred miles east of New York. You could have walked to the edge of the continental shelf. Baltimore Canyon, Hudson Canyon were exposed in the open air.”

  Outside the automobile window were three landscapes, trifocal, occupying separate levels in time and mind. Latently picture
d in the rock beside the road was the epicratonic sea of three hundred and twenty million years ago, with the Cincinnatia Islands off to the west somewhere, in what is known to geologists as Ohio Bay. There was also evidence of the deep ice of twenty thousand years ago, with its lobate front some distance to the south, near Canton, Massillon, and Wooster. And there was, of course, the slightly rumpled surface of the modern state of Ohio, looking like a bedspread on which someone had taken a nap. Not nearly as flat as the rock below was the undulating interstate, where diesel exhausts were pluming and Winnebagos were yawing in the wind.

  “The goal of many geologists is to make time-lapse maps of earth history,” Anita remarked. “Look at topographic maps from just a hundred years ago for coastal areas of low relief, and the changes are tremendous.”

  We went through a ten-metre roadcut of massive sandstone so rich in iron it had rusted the road. Being tough by comparison with its neighboring rock, it stood high and formed a hill, and hence it had been blasted to convenience the interstate. “That is one hell of a sandstone,” Anita said with enthusiasm, seeing in it something I could not discern.

  We crossed a river. “That was the well-known Cuyahoga,” she said. “If you swim in it, you dissolve.”

  The Cuyahoga was flowing south. It rises in northeasternmost Ohio, runs south into Akron, then reverses its direction, swinging north through Cleveland and into Lake Erie.

  More warning signs flashed by. “STAY AWAKE! STAY ALIVE!”

  Anita said, “I’m trying. I’m trying.”

  Now spanning the road was an Italianate steel-arch bridge, standing on Berea sandstone, a fragment of the Berea Delta, of early Mississippian age, which had extended its bird-foot shape far into Ohio Bay. We stopped, and picked quartz pebbles the size of golf balls out of a conglomerate there. “These would have been just offshore,” she said. “You can take the pebbles out of the rock with your hands because it was never heated up like the conglomerate at the Delaware Water Gap. This was never buried much. It is not well lithified. It hasn’t experienced enough heat to get tough.”

  A few miles west, we crossed the Cuyahoga River again, and looked down some distance from the interstate bridge into the Cuyahoga’s extensively reamed-out valley, with its modest, meandering stream.

  “It’s an underfit stream,” said Anita. “A little half-ass stream in a valley made wide by glacier ice. The Cuyahoga’s valley was steepened and entrenched, like Yosemite.”

  “You are comparing the Cuyahoga Valley with Yosemite?”

  “Technically.”

  We left the interstate and followed the valley into Cleveland. The Cuyahoga River had suffered a bad press. When it caught fire some years before, it attracted national attention. Its percentage of water had become low relative to its content of hydrogen in various combinations with carbon. The river burned so fiercely that two railroad bridges were nearly destroyed. There was no mention in the papers of the good things the river had done. It had made parks. It had been there before the glacier ice and had cut down five hundred feet through Mississippian formations into Senecan and Chautauquan time—stages of the late Devonian. It cut deep ravines, which the ice later broadened into canyons. The ice augered through the V-shaped valley and turned it into a U. Which is what ice did at Yosemite—with the difference that the walls of Yosemite are speckled white granite, while the canyon walls of Cleveland are flaky black gasiferous anoxic shale. As mud, the shale was deposited in quiet water in a late Devonian sea. The rock contains the unoxidized remains of so many living things that it is by volume as much as twenty per cent organic. In thin laminations, it grew layer upon layer—paper shale. “The water was so quiet you can trace the same little lens forever,” Anita said. “The formation produces gas like crazy. The gas migrates up into the sandstone above, which holds it. Berea sandstone. People drill their own wells to the Berea and heat their homes.” Much of Cleveland’s metropolitan-park system is in the deep Yosemite of the Cuyahoga River, under paper-flake carbon cliffs—a natural world of natural gas.

  Like the Cuyahoga today, most rivers in Ohio before the recent ice sheets looked for outlets to the north and northwest. Nearly all were wiped away by the planing drive of ice. Water pooled against the glacial front and spilled away to the south and west. It skirted the ice, roughly tracing its southernmost outline, forming a new river system and a “periglacial valley”—the Ohio River, the Ohio Valley.

  When Darwin published The Origin of Species, its affront to organized religion did not altogether exceed the dismay that was felt in science. Even Sir Charles Lyell said, “Darwin goes too far.” Thomas Henry Huxley and a few others were supportive, but almost every paleontologist in the British Isles was flat negative, and the geologist Adam Sedgwick, of Cambridge University, who, with Murchison, had discerned and established the Devonian system, described himself reading Darwin “with more pain than pleasure.” He said, “Parts of it I admired greatly, parts I laughed at till my sides were almost sore; other parts I read with absolute sorrow, because I think them utterly false and grievously mischievous. Many … wide conclusions are based upon assumptions which can neither be proved nor disproved … . Darwin has deserted utterly the inductive track and taken the broadway of hypothesis.” Applause for Darwin was even sparer from scientists across the Channel, with the notable exception of the Belgian geologist J. J. d‘Omalius d’Halloy, who, as it happened, had subscribed from the beginning to Louis Agassiz’s glacial theory as well, and whose Terrain Cretace was the discovery ground for the worldwide Cretaceous system.

  In the United States, by contrast with Europe, geologists, biologists—the scientific community at large—were for the most part quick supporters and early participants in the sweep of evolution. In the United States, also, there was a notable exception. He was Professor Louis Agassiz, of Harvard University. He had crossed the Atlantic and given a few lectures. He stayed for the rest of his life. He became, as he has remained, one of the most celebrated professors in the history of American education. It was a renown that rested largely on his amazing and infectious capacity for talking about ice. Never mind that he could not speak schoolroom English. His words drew pictures of glaciers in motion, many thousands of feet thick and larger by far than the Sahara. His words drew pictures of glacier ice over Boston, in the act of depositing Cape Cod; of glacier ice over Bridgeport, in the act of depositing Long Island; of ice retreating from Concord, leaving Walden Pond. Harvard was, at core, a drumlin, a glacial coprolite, packed in recessional outwash. America excited Agassiz, as well it might, for it had held the greater part of the ice he had dreamed of, covering the world. He went to Lake Superior and paddled its shoreline in a bark canoe. The features he saw there he had known in Neuchatel. He went to the Hudson Highlands and remembered the highlands of the Rhine. “The erratic phenomena and the traces of glaciers … everywhere cover the surface of the country,” he wrote. “Polished rocks, as distinct as possible; moraines continuous over large spaces; stratified drift, as on the borders of the glacier of Grindelwald.” He went to the Connecticut Valley: “The erratic phenomena are also very marked in this region; polished rocks everywhere, magnificent furrows on the sandstone and on the basalt, and parallel moraines defining themselves like ramparts upon the plain … . What a country is this! All along the road between Boston and Springfield are ancient moraines and polished rocks. No one who had seen them upon the track of our present glaciers could hesitate as to the real agency by which all these erratic masses, literally covering the country, have been transported. I have had the pleasure of converting already several of the most distinguished American geologists to my way of thinking.”

  Henry David Thoreau took Agassiz’s book out of the Harvard library and returned it a few weeks later—perhaps unread. Apparently, Thoreau never knew that Walden Pond was a glacial kettle, had no idea that he lived among moraines and drumlins, icetransported hills. Although he and Agassiz were acquainted and shared the same part of Massachusetts for sixteen years, there
is in Thoreau’s work no discussion of glaciation. Thoreau evidently never suspected that all his Nausets and Chesuncooks, Merrimacks and Middlesex ponds had been made and shaped by ice.

  Agassiz was so caught up in glacial and general geology that he would try to teach it to stagecoach drivers. He believed that anyone, given a little help, could understand the nature of the earth. In Boston, in order to make his case perfectly and avoid the rockslides of his Franco-Germanic accent and syntax, he announced that he would give a series of lectures in French on the Epoque Glaciaire. People paid to hear it, and he preserved their admiration in recrystallized mots justes. When he spoke of the Jura, the Pennine Alps, and the boulders in the valleys between, no one was as moved as Agassiz. His great range of expression did not exclude tears. With his large forehead, full lips, aquiline nose, and shoulder-flowing hair, he all but held a baton in his hand with which to conduct the movements of the ice. One Saturday a month, he met with his friends for a late, seven-course lunch from which no one was in a hurry to go home. They would meet, like as not, at “Parker’s” in Boston, in a room looking out on City Hall. “Agassiz always sat at the head of the table by native right of his large good-fellowship and intense enjoyment of the scene,” his friend Sam Ward eventually recalled. Henry Wadsworth Longfellow generally sat at the other end, with Oliver Wendell Holmes on his right. Holmes preferred his window-light over the shoulder. On around the table were James Russell Lowell, John Greenleaf Whittier, Nathaniel Hawthorne, Ralph Waldo Emerson, Richard Henry Dana, Jr., Ebenezer Hoar, Benjamin Peirce, Charles Eliot Norton, and James Elliot Cabot, among others. Agassiz, with a glass of wine at his elbow, would sometimes conduct the conversation with two lighted cigars, one in each hand. Holmes said of him that he had “the laugh of a big giant.” Longfellow was relieved and pleased when Agassiz told him he liked the description of the glacier in “Hyperion.” Emerson in his journal described Agassiz as “a broad-featured unctuous man, fat and plenteous.” Sir Charles Lyell was invited, on his visits to America. United States Senator Charles Sumner was occasionally present as well. Agassiz was indifferent to him, because Sumner showed too much interest in politics.