HOW long did it take for the once-molten Earth to cool to its modern temperature? The question nagged at Georges-Louis Leclerc, the Comte de Buffon. To work it out, he heated iron balls of different sizes and measured how long it took them to cool enough to touch. It is said he asked only women to help him with this experiment – their hands being more sensitive, naturally, for measuring. With his timescale calibrated, he scaled up to Earth size. He knew the error margins were large; his private notes show estimates ranging from 75,000 to 3 million years. The year was 1778. Even the lower estimate, which he went on to publish, smashed the Biblical timescale of a mere few thousand years.
This result could have been received poorly by the religious authorities of the day, represented by France’s powerful theological college at the Sorbonne. So in his book, Les Époques de la Nature (), Buffon first did some explaining. He wrote a discourse at the front of the book, arguing that the Biblical timescale was metaphorical rather than literal, and that in any case his “purely hypothetical” ideas could in no way harm the “unchanging axioms” of the sacred word. There were grumbles in high clerical circles, but the stratagem worked. He was left to get on with his science, as he had for half a century.
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Buffon’s was an unlikely scientific career. His father was a lawyer and tax-collector in the village of Montbard in Burgundy and the young Georges-Louis was destined to become a dignitary in local government. After the death of his uncle, the inheritance was used to buy the lord’s rights to the nearby castle of Buffon. Georges-Louis was sent to study law, but his fascination with the natural world made him determined to study science. His father was aghast – the profession of scientist then barely existed, and certainly carried no social standing. But the young man got his way, and soon after won yet another battle with his father, over the rights to the castle.
Bed be damned
Gaining wealth and a title fuelled Buffon’s ambition. The first problem the self-confessed sloth had to deal with was getting up in the morning. He employed a servant to physically drag him out of bed at dawn so he could commence the disciplined 12 to 14-hour working days that he would maintain for the rest of his life. The solid graft paid off. He first made his reputation with mathematics, held a position at the French Academy of Sciences and was put in charge of Louis XV’s botanic gardens and later the royal collections of scientific objects.
But Buffon’s prodigious working hours were largely aimed at developing his view of the world: of minerals, plants and animals, including humans. Published over his lifetime in 36 volumes, his Histoire Naturelle put him on a par with Voltaire and Jean-Jacques Rousseau as a leading thinker of his day; one that often ruffled feathers, even overseas. He once conjectured that the mammals of the Americas were enfeebled latecomers, developing in cooler, less life-friendly times. This idea stung a young Thomas Jefferson – a gifted natural historian who later became US president. Jefferson gathered evidence of the splendour of native American mammals and went so far as to send Buffon a crate containing the skin and bones of a large moose as demonstration. They arrived decayed and smelly, probably defeating the point.
After dealing so comprehensively with the natural world, Buffon widened his sights. He decided to reconstruct all of Earth’s history, from its fiery beginnings to an anticipated freezing oblivion, in a single volume – Les Époques. It was arguably the first science-based history of Earth, and Buffon’s lively prose generated the kind of atmosphere that Jules Verne would later evoke. He designed “burning mirrors” that could melt rock, and dug deep shafts in search of fossils. His writing style made this groundbreaking research accessible to the public, something many of his peers disapproved of, or perhaps envied. A fellow savant, wrote to him: “Yet more Buffonades… A fine adventure story… to be devoured by the maidservant and amuse the lackey.”
Hugely ambitious, Les Époques tried to tell Earth’s story as an interconnected whole, despite the inevitable chasms in the scientific knowledge of the day. For example, his attempted to explain the sun’s light and heat via forces exerted by the bodies orbiting around it. Absurd? Well, we now know that gravitational forces drive the volcanism on Jupiter’s moon, Io, so at a time when nuclear fusion could not yet be dreamed of, Buffon’s answer was at least thoughtfully wrong.
But it’s what he got right that amazes. His Earth narrative includes some prescient deductions: that the fossils found deep in rock strata represent organisms now extinct, for instance. Buffon said it would be useful to study these systematically and compare them with living organisms, foreseeing the discipline of palaeontology. Some of his insights into ancient environments were stunning, as when he wrote that coal was formed in ancient conditions akin to those of the tropical swamps of Guyana – an interpretation still valid today.
He saw that there was a more shallowly buried – and hence more recent – history too. At the time, bones from elephants, rhinoceroses and hippopotamuses were showing up a little below the ground’s surface in Siberia, for example. This fit his model of an Earth whose overall temperature was heading towards a final deep freeze. The far north, he reasoned, must have once been as hot as Africa is today – an early stab at palaeoclimatology.
The seventh and last epoch described in Les Époques was that of humankind. It had a telling subtitle: “When the power of man assisted that of Nature”. Buffon thought global climate was still cooling. After all, Alpine glaciers had been known to overwhelm villages, suggesting an encroaching freeze. But he thought human action could delay Earth’s frigid doom – by burning wood and coal, among other measures. It was an optimistic first take on the Anthropocene concept, though ironic in the light of today’s climate woes.
Buffon ended Les Époques by looking forward to humanity progressing through the peaceful use of science. The book was admired by some – it is said Catherine the Great of Russia was captivated by it – but disparaged by others for its “Buffonades”. Such criticism did not unduly trouble Buffon: his position on style was always clear. “Only those works which are well-written will pass to posterity,” he wrote. “The amount of knowledge, the uniqueness of the facts, even the novelty of the discoveries are no guarantees of immortality… These things are exterior to a man but style is the man himself.”
“A fine adventure story, to be devoured by the maidservant and amuse the lackey“
Despite his confidence, the perception of Buffon as a phrasemonger did not help his later reputation, nor did his dismissal of Carl Linnaeus’s newfangled but ultimately enduring scientific naming system. He died of natural causes in 1788, aged 80. It was the year before the French Revolution, which swept away the . His timely death spared him a date with the guillotine (his son was not so lucky).
The new wave of scientists had their own careers to burnish, and their stars came to eclipse Buffon’s. Yet his breathtaking ambition in reconstructing an evidence-based, holistic account of Earth and its inhabitants should not be forgotten. Buffon brought real science to the people with his vivid writing. And that’s something to be celebrated in any era.
This article appeared in print under the headline “Earth will freeze if we don’t step in”
