The Invention of Nature (27 page)

Old friends tried to help. Bolívar, who was by then in Lima attempting to purge the Spanish from Peru, wrote to Francia, requesting Bonpland’s freedom as well as threatening to march to Paraguay to rescue him. Francia could count on him as an ally, Bolívar said, but only if the ‘innocent whom I love, will not become the victim of injustice’. Humboldt also did what he could through his European contacts. He dispatched letters to Paraguay signed by famous scientists and asked his old London acquaintance George Canning (who by now was the Foreign Secretary) to involve the British consul in Buenos Aires – but Francia refused to release Bonpland.

Meanwhile Humboldt’s own travel plans had come to a standstill. Despite the support of the Prince Regent and of George Canning, the East India Company continued to refuse Humboldt entrance to India. It felt as if he had been going round in circles in the past few years. Whereas his years in Latin America, and those just after, had been marked by breathless activity and a constant forward trajectory, Humboldt now felt choked by stagnation. He was no longer the dashing, heroic young explorer who was celebrated for his adventures but a distinguished and respected scientist in his fifties. Most of his middle-aged contemporaries would have been glad to be admired and courted for their knowledge, but Humboldt was not ready to settle. There was still so much to do. He was so fretful that one friend called his restlessness a ‘maladie centrifuge’ – Humboldt’s centrifugal illness.

Frustrated, annoyed and upset, Humboldt felt cheated and unappreciated. He now announced that he would turn his back on Europe. He would move to Mexico where he planned to establish an institute for the sciences. In Mexico, he would surround himself with scholarly men, he told his brother in October 1822, and enjoy the ‘liberty of thought’. At least there, he was ‘greatly respected’. He was absolutely certain that he would spend the rest of his life outside Europe. A few years later, Humboldt told Bolívar that he still planned to move to Latin America. No one really knew what Humboldt wanted or where he intended to go. Wilhelm summed it up when he said: ‘Alexander always envisages things as being huge, and then not even half of it happens.’

The East India Company might have been uncooperative but it seemed that everybody else in Britain was enthusiastic about Humboldt. Many of the British scientists whom he had met in London now visited him in Paris. The famous chemist Humphry Davy came again, as did John Herschel, the son of astronomer William Herschel, and Charles Babbage, the mathematician hailed today as the father of the computer. Humboldt ‘derived pleasure from assisting’, Babbage said, no matter how famous or unknown the caller. Oxford geologist William Buckland was equally excited to meet Humboldt in Paris. Never had he heard a man talk faster or with more brilliance, Buckland wrote to a friend. As always, Humboldt was generous with his knowledge and collections, opening his cabinet and notebooks to Buckland.

One of the most significant scientific encounters was with Charles Lyell, the British geologist whose work would help Charles Darwin shape his ideas about evolution. Fascinated by the formation of the earth, Lyell had travelled across Europe in the early 1820s to investigate mountains, volcanoes and other geological formations for his revolutionary work, Principles of Geology. Then, in the summer of 1823, around the same time as news of Bonpland’s imprisonment had reached Bolívar, an enthusiastic twenty-five-year-old Lyell went to Paris with his bags full of introductory letters to Humboldt.

Since his return from Latin America, one of Humboldt’s projects had been to collect and compare data on rock strata across the globe. After almost two decades he had finally published the results in his Geognostical Essay on the Superposition of Rocks, just a few months before Lyell reached Paris. This was exactly the kind of information Lyell needed for his own research. The Geognostical Essay, Lyell wrote, was ‘a famous lesson to me’. It would have placed Humboldt in the highest ranks of the science world, he believed, even if he published nothing else. During the next two months, the two men spent many afternoons together, talking about geology, Humboldt’s observations at Mount Vesuvius and mutual friends in Britain. Humboldt’s English was excellent, Lyell noted. ‘Hoombowl’, Lyell wrote to his father – the way Humboldt’s French servant pronounced his name – gave him plenty of material and useful data.

They also discussed Humboldt’s invention of isotherms, the lines that we see on weather maps today and which connect different geographical points around the globe that are experiencing the same temperatures.1 Humboldt had come up with the design for his essay On the Isothermal Lines and the Distribution of Heat on the Earth (1817) in order to visualize global climate patterns. The essay would help Lyell to form his own theories, and also marked the beginning of a new understanding of climate – one on which all subsequent studies about the distribution of heat were based.

Until Humboldt’s isotherms, meteorological data had been collected in long tables of temperatures – endless lists of different geographical places and their climatic conditions which gave precise temperatures but were difficult to compare. Humboldt’s graphic visualization of the same data was as innovative as it was simple. Instead of confusing tables, one look at his isotherm map revealed a new world of patterns that hugged the earth in wavy belts. Humboldt believed that this was the foundation of what he called ‘vergleichende Klimatologie’ – comparative climatology. He was right, for today’s scientists still use them to understand and depict climate change and global warming. Isotherms enabled Humboldt, and those who followed, to look at patterns globally. Lyell utilized the concept to investigate geological changes in relation to climatic changes.

Map showing isotherms (Illustration Credit 14.1)

The central argument of Lyell’s Principles of Geology was that the earth had been shaped gradually by minute changes rather than by sudden catastrophic occurrences such as earthquakes or floods as other scientists thought. Lyell came to believe that these slow forces were still active in the present day which meant that he had to look at the current conditions in order to learn about the past. To argue his case for the influence of gradual forces, and to move scientific thinking away from the more apocalyptical theories of the earth’s beginning, Lyell had to explain how the surface of the planet had cooled gradually. He ‘read up’ on Humboldt, Lyell later told a friend, while working on his own theory.

Humboldt’s detailed analysis came to the surprising conclusion that temperatures were not the same along the same latitude as had been previously assumed. Altitude, landmass, proximity to oceans and winds also influenced heat distribution. Temperatures were higher on land than on sea, but also lower at higher elevations. This meant, Lyell concluded, that where geological forces had elevated the land, temperatures dropped accordingly. In the long term, he argued, this upward drift brought a cooling effect to the world climate – as the earth changed geologically, so did the climate. Years later, when pressed by a reviewer of Principles of Geology to define the moment of ‘a beginning’ of his theories, Lyell said it had been the reading of Humboldt’s essay on isotherms – ‘give Humboldt due credit for his beautiful essay’. In his own work, Lyell said, he had only given Humboldt’s climate theories a ‘geological application’.

Humboldt helped young scientists whenever he could, intellectually but also financially, no matter how difficult his own situation. So much so that his sister-in-law, Caroline, worried that his so-called friends exploited his kindness – ‘he eats dry bread, so that they can eat meat.’ But Humboldt didn’t seem to care. He was the hub of a spinning wheel, forever moving and connecting.

He wrote to Simón Bolívar to recommend a young French scientist who planned to travel through South America, as well as equipping the scientist with his own instruments. Similarly, Humboldt introduced a Portuguese botanist who intended to emigrate to the United States to Thomas Jefferson. The German chemist Justus von Liebig, who would later become famous for his discovery of the importance of nitrogen as a plant nutrient, recounted how meeting Humboldt in Paris had ‘laid the foundation of my future career’. Even Albert Gallatin, the former US Secretary of the Treasury, who had first met Humboldt in Washington and then again in London and Paris, found himself so inspired by Humboldt’s enthusiasm for indigenous people that he threw himself into studies of Native Americans in the United States. Today Gallatin is regarded as the founder of American ethnology; the reason for his interest, Gallatin wrote, was ‘the request of a distinguished friend, Baron Alexander von Humboldt’.

As Humboldt helped friends and fellow scientists to advance their careers and travels, his own chances of being allowed to enter India had dwindled to nothing. He fed his wanderlust with trips through Europe – Switzerland, France, Italy and Austria – but it wasn’t the same. He was unhappy. It was also becoming increasingly difficult to justify his decision to live in Paris to the Prussian king. Since Humboldt’s return from Latin America two decades earlier, Friedrich Wilhelm III had repeatedly pressed him to return to Berlin. For twenty years the king had paid him an annual stipend with no strings attached. Humboldt had always argued that he needed Paris’s scientific environment to write his books but the climate in the city and France had changed.

After Napoleon’s removal and imprisonment on the remote island of St Helena in 1815, the Bourbon monarchy had been reinstated with the crowning of Louis XVIII2 – the brother of Louis XVI who had been guillotined during the French Revolution. Though absolutism had not returned to France, the country that had held the torch of liberty and equality had become a constitutional monarchy. Only one per cent of the French population was eligible to elect the lower house of parliament. Though Louis XVIII respected some liberal views, he had arrived in France from exile with a train of ultra-royalist émigrés who wanted to return to the old ways of the pre-revolutionary Ancien Régime. Humboldt had watched them coming back and had seen how they burned with hate and a desire for revenge. ‘Their tendency to absolute monarchy is irresistible,’ Charles Lyell had written to his father from Paris.

Then in 1820 the king’s nephew, the Duc de Berry – third in line to the throne – was murdered by a Bonapartist. After that there was no holding back the royalist tide any more. Censorship became harsher, people could be held without trial and the wealthiest people received a double vote. In 1823 the ultra-royalists gained the majority in the lower house of parliament. Humboldt was deeply upset, telling one American visitor that all it took was one look at the Journal des Débâts – a newspaper founded in 1789, during the French Revolution – to see how the freedom of the press had become curtailed. Humboldt was also beginning to feel uncomfortable at the way that religion, with all its constraints on scientific thinking, was reasserting its grip on French society. With the return of the ultra-royalists, the power of the Catholic Church rose. By the mid-1820s new church spires were rising across the Paris skyscape.

Paris was ‘less disposed than ever’ to be a centre for the sciences, Humboldt wrote to a friend in Geneva, as the funds for laboratories, research and teaching were slashed. The spirit of enquiry was stifled as scientists found themselves having to curry favours from the new king. The savants had become ‘pliant tools’ in the hands of politicians and princes, Humboldt told Charles Lyell in 1823, and even the great George Cuvier had sacrificed his genius as a naturalist for a new quest for ‘ribbons, crosses, titles and Court favours’. There was so much political wrangling in Paris that governmental positions seemed to change as quickly as in a game of musical chairs. Every man he met now, Humboldt said, was either a minister or an ex-minister. ‘They are scattered thick as the leaves in autumn,’ he told Lyell, ‘and before one set have time to rot away, they are covered by another and another.’

French scientists feared that Paris was going to lose its status as a centre for innovative scientific thinking. At the Académie des Sciences, Humboldt said, the savants did little and what little they did often ended in quarrels. Even worse, the scholars had formed a secret committee to sanitize the library there – removing books that propounded liberal ideas like those written by Enlightenment thinkers such as Jean-Jacques Rousseau and Voltaire. When the childless Louis XVIII died in September 1824 his brother Charles X, the leader of the ultra-royalists, became king. All those who believed in liberty and in the values of the revolution knew that the intellectual climate could only become more repressive.

Humboldt himself had changed too. Now in his mid-fifties, his brown hair had turned silver-grey and his right arm was almost paralysed by rheumatism – the long-term effect, he explained to friends, of sleeping on wet ground in the rainforest at the Orinoco. His clothes were old-fashioned, tailored in the style of the years just after the French Revolution: fitted striped breeches, a yellow waistcoat, a blue tailcoat, a white cravat, tall boots and a shabby black hat. No one in Paris, a friend remarked, dressed like that any more. Humboldt’s reasons were as political as they were parsimonious. With his inheritance long gone, he lived in a small plain apartment overlooking the Seine, consisting only of a sparsely furnished bedroom and a study. Humboldt had neither the money nor the taste for luxuries, elegant clothes or opulent furniture.

Then, in autumn 1826, after more than two decades, Friedrich Wilhelm III finally ran out of patience. He wrote to Humboldt that ‘you must already have completed the publication of the works, which you believed could only be accomplished satisfactorily in Paris.’ The king could no longer extend permission for him to stay in France – a country that, in any event, ‘ought to be an object of hatred to every true Prussian’. As Humboldt read that the king was now awaiting his ‘speedy return’, there could be no doubt that this was an order.

Humboldt desperately needed the money from his annual stipend because the cost of his publications had left him, he admitted, ‘poor as a church mouse’. He had to live on what he earned but he was useless when it came to his finances. ‘The only thing in heaven or earth that M. Humboldt does not understand,’ his English translator had remarked, ‘is business.’