Agassiz included in his talk his own explanation for the Parallel Roads of Glen Roy. The ‘roads’, he said, were the remnants of glacial lakes – former shorelines not of the sea, but of a freshwater lake dammed by a glacier, thus directly contradicting Darwin’s paper given two years earlier. Darwin was at the meeting, as was Sedgwick, who joined in the fiery debate which ‘kept up till near midnight’. He later read Agassiz’s study of glaciers, and found it ‘excellent’, though he felt in ‘the last chapter he loses his balance, and runs away with the bit in his mouth’.1
Overall, Agassiz’s theory solved many puzzles, not least the existence of large boulders totally unlike the rocks around them. Lyell had suggested that these erratics had been carried by floating icebergs, but Agassiz’s explanation was more convincing, and answered other questions as well. Glaciers carried debris as well as boulders and deposited them as they crept slowly along, scratching the rocks underneath. (By the ninth edition of Principles, Lyell would emphatically attribute the presence of erratic boulders on the Alpine peaks to glacial actions.2)
Buckland, then president of the society, endorsed him wholeheartedly. Turning the chair of the meeting over to George Bellas Greenough, he told of his own conversion. He described himself as having been a ‘sturdy opponent of Professor Agassiz when he first broached the glacial theory’, but, after going to the Alps, he had been persuaded. Buckland then read the first part of his memoir on the evidence of glaciers in Scotland and the north of England and spelled out his own view: the Glen Roy roads had been made by successive inland lakes, dammed by a glacier. Ever the joker, Buckland condemned those who questioned the validity of scratches, grooves and polished surfaces of the glacial mountains ‘to be damned to the pains of eternal itch without scratching’.3
Agassiz was challenged by Greenough, the founding president of the Geological Society: ‘Does Prof. Agassiz suppose that the Lake of Geneva was occupied by a glacier 3,000 feet thick?’
Agassiz shouted back: ‘At least!’4
Greenough was unimpressed. The glacial theory, he said, was the ‘climax of absurdity in geological opinions’. Murchison, for his part, complained about the poetic terms Agassiz had used to describe glacial phenomena. Buckland, however, defended Agassiz’s choice of words. He said that Agassiz had done well to revive de Saussure’s expressive phrase roches moutonées (rounded, elongated bedrocks resembling the backs of sheep) whose characteristic shape was attributed to glaciers passing over them.
Murchison was sarcastic. If ice were the explanation for marks on the surface of many rocks, ‘the day will come when . . . Highgate Hill will be regarded as the seat of a glacier, & Hyde Park & Belgrave Square will be the scene of its influence’. (The joke was self-flattering, for all present knew that Murchison had recently moved into fashionable Belgrave Square.)
Early the next year, in his presidential address, Buckland summarised his conclusions on glaciers and in particular on the roads of Glen Roy: these had been caused by two glaciers descending from the mountain of Ben Nevis across the valley of the Spean.
In fact, after a few months, Agassiz’s ideas were accepted. From Edinburgh the naturalist Edward Forbes wrote to the professor, now back at the University of Neuchâtel, ‘You have made all the geologists glacier-mad here . . . they are turning Great Britain into an ice-house.’5
Louis Agassiz, born in 1807, had received the degree of doctor of medicine in Munich in 1830, but his fascination with extinct forms of fish had moved him into natural history. He went to Paris and studied geology with Alexander von Humboldt and zoology with Cuvier. At the age of twenty-two he produced his first book (based on collections brought back by explorers) on the history of Brazilian fossil fish. Extending his interest to European varieties, he wrote a history of freshwater fish in central Europe and then became professor of natural history at Neuchâtel. He received grants for research from Frederick William III, King of Prussia. His fame spread with the publication in 1838 of the first volume of his Recherches sur les poissons fossiles.
Agassiz had first come to Britain in 1833 when Buckland invited him to study the remarkable fish fossils in the Old Red Sandstone. He met the Scottish geologist Hugh Miller, who would write five volumes on the subject. The following year he went to Lyme Regis and examined the fossil fish collections of geologists Elizabeth Philpot and Mary Anning. He named a species of fish after Anning: Belenostomus anningiae. In the 1843 edition of his Recherches sur les poissons fossiles, he thanked both Philpot and Anning.
In Switzerland in 1836 he inspected the glaciers of the valleys of Chamonix and Diablerets and also the moraines of the Rhône Valley. There he heard his friend Jean de Charpentier advocate the glacial concept as an explanation for the moraines and erratic blocks in the Alpine regions of Switzerland.
Perhaps de Charpentier should have had the credit for discovering the Ice Age. Nonetheless, it was Agassiz who named it and who delivered his theory in an address to the Swiss Society of Natural History in 1837. This dramatic announcement – that in relatively recent history a massive glacier had covered Switzerland and central Europe – drew Buckland to Switzerland the following year to tell Agassiz that the same evidence could also be found in Scotland. Buckland’s speculations opened Agassiz’s imagination to the concept of a giant ice sheet: not a separate one for Switzerland and another for Scotland, but one huge blanket of ice. The theory was welcome to Buckland, for it swept away any remaining delusions of deluges. Floods of ice, not floods of water, had shaped the landscape.
In the late summer of 1840, Agassiz came to Scotland for a third visit, this time for the Glasgow meeting of the British Association for the Advancement of Science. Arriving in August, Agassiz toured the Highlands with Buckland and had no difficulty in finding examples of striations, glacial polish, erratics, roches moutonées and moraines just as he had seen in Switzerland. Buckland then led him to the puzzling Parallel Roads of Glen Roy. Gripped by the spectacle, Agassiz wrote his own description – ‘around the walls of the Glen Roy valley run three terraces, one above the other, at different heights, like so many roads artificially cut in the sides of the valley, and indeed they go by the name of the “parallel roads”’6 – and concluded that they were the result of glacial action. He did not keep his theory to himself: on 3 October 1840, from Fort Augustus, he wrote to the influential daily newspaper the Scotsman, which four days later published his letter announcing his solution to the problem of the Parallel Roads of Glen Roy:
at the foot of Ben Nevis, and in the principal valleys, I discovered the most distinct moraines and polished rocky surfaces, just as in the valleys of the Swiss Alps, in the region of existing glaciers; so that the existence of glaciers in Scotland at early periods can no longer be doubted. The parallel roads of Glen Roy are intimately connected with this former occurrence of glaciers, and have been caused by a glacier from Ben Nevis. The phenomenon must have been precisely analogous to the glacier-lakes of the Tyrol, and to the event that took place in the valley of Bagne.7
When Agassiz moved on to Ireland, Buckland went to visit Lyell on the family’s Kinnordy estate and there converted him to Agassiz’s glacial theory. Buckland reported back to Agassiz: ‘Lyell has adopted your theory in toto!!!!’ for ‘solving a host of difficulties that have all his life embarrassed him’.8
Indeed Lyell had. He introduced new material into the 1840 edition of his Principles, writing in the preface: ‘a chapter has been introduced for the first time on the power of river-ice, glaciers, and ice-bergs, to transport solid matter, and to polish and furrow the surface of rocks. The facts and illustrations contained in this chapter have been almost entirely derived from my private correspondence during the last four years, or from new publications.’9 These must have included Agassiz’s two-volume Etudes sur les glaciers, dedicated in part to Charpentier, published later that year.
In 1846 Agassiz left Britain – for good, as it turned out – when his name was put forward by Lyell to give the distinguished Lowell Institute
lectures in Boston, Massachusetts. En route Agassiz’s ship stopped at Halifax, Nova Scotia, and he was excited to observe ‘the familiar signs, the polished surfaces, the furrows and scratches, the line engraving of the glacier . . . and I became convinced . . . that here also this great agent had been at work’.10
In America he discovered a country where the study of geology was well developed, and a Boston society that loved him and his lectures. Agassiz would stay on to become Harvard’s first professor of natural history. There his teaching enthralled the young Henry Adams, who wrote in his autobiography that ‘the only teaching that inspired his imagination was a course of lectures by Louis Agassiz on the Glacial Period and Palaeontology, which had more influence on his curiosity than the rest of the college instruction together’.11
Agassiz married a Bostonian (his first wife having died in Switzerland). Her name was Elizabeth Cabot Cary and in 1879 she became co-founder and first president of Radcliffe College, the women’s liberal arts college (soon dubbed ‘Harvard’s Annex’, now formally part of Harvard). In 1859, through his efforts, Harvard established the Museum of Comparative Zoology, which holds Agassiz Hall. He was the museum’s first director.
Agassiz’s good looks and urbanity, as well as his knowledge, were much admired in both Britain and the United States. In 1856 he received the Wollaston Medal from the Geological Society of London for his work on fossil ichthyology and in 1861 was awarded the Royal Society’s illustrious Copley Medal. In New England the poet Henry Wadsworth Longfellow composed ‘The fiftieth birthday of Agassiz’ in his honour. Agassiz’s own work now had American focus: a multi-volume Natural History of the United States was published between 1857 and 1862; he had completed only four of his planned ten volumes by his death in 1873. By then he was perhaps the most famous scientist in the world.
In recent years Agassiz has been much criticised for his theory that there were several human species, not just different races of a single species. But such ideas were not unusual at the time and should not be used retrospectively to cloud his great contributions to natural history. In 1884, another New England man of letters, Oliver Wendell Holmes, included Agassiz in a poem, ‘At the Saturday Club’. The club had started in 1855 with monthly informal meetings at the Parker House in Boston. It drew together poets, scientists and philosophers to dine and enjoy good conversation. In Holmes’s poetic reconstruction:
There, at the table’s further end I see
In his old place our Poet’s vis-à-vis,
The great PROFESSOR, strong, broad-shouldered, square,
In life’s rich noontide, joyous, debonair.
His social hour no leaden care alloys,
His laugh rings loud and mirthful as a boy’s –
That lusty laugh the Puritan forgot,–
What ear has heard it and remembers not?
. . .
How does vast Nature lead her living train
In ordered sequence through that spacious brain,
As in the primal hour when Adam named
The new-born tribes that young creation claimed!–
How will her realm be darkened, losing thee,
Her darling, whom we call our – AGASSIZ!12
This poetic portrait of Agassiz appropriately included a reference to his greatest discovery – the slow creeping crawl of the glacier.
14
FOOTPRINTS IN PENNSYLVANIA
In 1841, five years before he put forward Agassiz’s name, Charles Lyell had given his own series of lectures at the illustrious Lowell Institute in Boston. Lyell was delighted to have the opportunity of seeing America for the first time, and he would see a great deal: a thirteen-month trip, with his wife Mary, was projected. Even so, he was anguished at the thought of being parted from Darwin for a whole year.
The two men would not be London neighbours much longer. Darwin, now married, with a pregnant wife and increasingly unwell himself, was planning a move from their Bloomsbury home, Macaw Cottage, to a house in the country, in Downe, Kent. At first Charles and Emma had liked London. ‘We are living a life of extreme quietness,’ he told a friend, ‘and if one is quiet in London, there is nothing like its quietness – there is a grandeur about its smoky fogs, and the dull distant sounds of cabs and coaches; in fact . . . I am becoming a thorough-paced Cockney.’1 But with his weight dropping and energy failing, he now found London ‘a vile and smoky place’.2
What would Lyell do without him? He moaned to Darwin in a letter: ‘It will not happen easily that twice in one’s life even in the large world of London a congenial soul so occupied with precisely the same pursuits, and with an independence enabling him to pursue them, will fall so nearly in my way.’3 Whenever they saw each other, they could not stop talking geology. Darwin told Emma how the Lyells had called on him one morning after church: ‘I was quite ashamed of myself today, for we talked for half-an-hour unsophisticated Geology, with poor Mrs. Lyell sitting by, a monument of patience. I want practice in ill-treating the female sex . . . few husbands seem to find it difficult to effect this.’4
With Mary, his wife of nine years, Lyell left from Liverpool in July 1841 on the steamship Acadia, which covered up to 250 miles per day. Casting his geologist’s eye on the Atlantic, he observed that the ocean changed from deep blue to green as it became shallower over the Newfoundland banks. On 31 July, after eleven days, they reached Halifax, Nova Scotia, and posted the letters they had written on the voyage. Thirty hours more saw them arrive in Boston. This was six months before the much-anticipated visit of Charles Dickens. When Dickens landed on 3 January 1842, he was mobbed in a wave of adulation that would continue during the rest of his American visit.
While Lyell had no such celebrity, he was far from unknown. In 1838 he had published Elements of Geology, devoted to stratigraphy and palaeontology and their use in dating rock strata. The new book was very successful, appearing in subsequent editions, with much interchanging of material between it and the best-selling Principles.
Unlike his travels in France, where everything seemed to contrast with England, in the United States Lyell was struck by ‘the resemblance of every thing I see and hear to things familiar at home’. The people especially, he thought, were ‘so very English’.5 (He wrote in 1841 before the great wave of Irish immigration began, after the start of the four-year potato famine.) It cannot have been long before Lyell saw the possibility of another bestseller. British interest in the country was intense and few visitors (emigrants apart) made the long ocean-crossing. Darwin, for one, had been no nearer America than the Galápagos.
Lyell was moved to recount his travels with the confidence of a reporter who knows that he is seeing what his readers will never see. ‘One of the first peculiarities that must strike a foreigner in the United States is the deference paid universally to the [female] sex, without regard to station,’ he noted. ‘Women may travel alone here in stage coaches, steamboats, and railways, with less risk of encountering disagreeable behaviour, and of hearing coarse and unpleasant conversation, than in any country I have ever visited. The contrast in this respect between the Americans and the French is quite remarkable.’6 He also observed that the social class divisions so apparent in England were of little interest here. When he asked the innkeeper to find his wagon driver, the landlord called out: ‘Where is the gentleman that brought this man here?’ Lyell was not accustomed to being called a ‘man’ while his employee was a ‘gentleman’.7
Lyell noticed that the wildflowers and weeds were very different from those in England; yet two-thirds of the seashells were the same species as British shells: ‘I shall have many opportunities of pointing out the geological bearing of this curious, and to me very unexpected fact.’ He noted also the striations and polished surfaces – the signs of glaciers. But why, if Boston was on the latitude of Rome, were its winters so cold?
Before giving his series of lectures, he and Mary set out on a tour to see the geologist’s dream: Niagara Falls. (Mary, having no children, was free to a
ccompany him on his travels. Regrettably for today’s reader, Lyell’s copious travel notes omit any mention of what his wife wore on these arduous field trips.) In 1841 getting to western New York State was no simple matter. Travelling merely from Boston to New York City was more complicated than crossing the Atlantic. First, from Boston, the Lyells went west to Springfield, Massachusetts – ‘by excellent railway’, as he would write in his subsequent Travels in North America; with Geological Observations on the United States, Canada and Nova Scotia. They covered the first hundred miles ‘in three hours and a half, for three dollars each’. They then ‘descended the River Connecticut in a steamboat’, stopping at Hartford to see a large mass of vertical rock columns of red sandstone, then at New Haven.
After admiring the fine avenues, Yale University and the East and West Rocks that flank the city, the Lyells embarked on a large steamship which took them in less than six hours to New York City. Yet another steamship took them up the Hudson River, where on its west bank Lyell admired the columnar basalt called the Palisades. Reaching Albany, he was happy to meet state government geologists and sympathised with their dismay that, after $200,000 (or, as he put it, 40,000 guineas) had been expended on exploring New York State’s mineral structure, they learned that no coal would ever be discovered nearby. ‘This announcement caused no small disappointment, especially as the neighbouring state of Pennsylvania was very rich in coal.’8
Going by train from Albany to Niagara, Lyell was surprised to see ‘one flourishing town after another, such as Utica, Syracuse, and Auburn’ and a group of Oneida Indians offering for sale trinkets and moccasins of moose-deer skin and boxes of birch bark. Near Rochester, accompanied by the geological surveyor for northwestern New York, he saw the remains of a fossil mastodon and fragments of an ivory tusk. His main conclusion: the fossils of those North American rocks were not identical to those found in equivalent strata on the other side of the Atlantic.
Reading the Rocks Page 15