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 鈥� 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鈥檚 powerful theological college at the Sorbonne. So in his book, Les 脡poques 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 鈥減urely hypothetical鈥� ideas could in no way harm the 鈥渦nchanging axioms鈥� 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.
Advertisement
Buffon鈥檚 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鈥檚 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 鈥� 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鈥檚 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鈥檚 botanic gardens and later the royal collections of scientific objects.
But Buffon鈥檚 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 鈥� 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鈥檚 history, from its fiery beginnings to an anticipated freezing oblivion, in a single volume 鈥� Les 脡poques. It was arguably the first science-based history of Earth, and Buffon鈥檚 lively prose generated the kind of atmosphere that Jules Verne would later evoke. He designed 鈥渂urning mirrors鈥� 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: 鈥淵et more Buffonades鈥� A fine adventure story鈥� to be devoured by the maidservant and amuse the lackey.鈥�
Hugely ambitious, Les 脡poques tried to tell Earth鈥檚 story as an interconnected whole, despite the inevitable chasms in the scientific knowledge of the day. For example, his attempted to explain the sun鈥檚 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鈥檚 moon, Io, so at a time when nuclear fusion could not yet be dreamed of, Buffon鈥檚 answer was at least thoughtfully wrong.
But it鈥檚 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 鈥� an interpretation still valid today.
He saw that there was a more shallowly buried 鈥� and hence more recent 鈥� history too. At the time, bones from elephants, rhinoceroses and hippopotamuses were showing up a little below the ground鈥檚 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 鈥� an early stab at palaeoclimatology.
The seventh and last epoch described in Les 脡poques was that of humankind. It had a telling subtitle: 鈥淲hen the power of man assisted that of Nature鈥�. 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鈥檚 frigid doom 鈥� 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鈥檚 climate woes.
Buffon ended Les 脡poques by looking forward to humanity progressing through the peaceful use of science. The book was admired by some 鈥� it is said Catherine the Great of Russia was captivated by it 鈥� but disparaged by others for its 鈥淏uffonades鈥�. Such criticism did not unduly trouble Buffon: his position on style was always clear. 鈥淥nly those works which are well-written will pass to posterity,鈥� he wrote. 鈥淭he amount of knowledge, the uniqueness of the facts, even the novelty of the discoveries are no guarantees of immortality鈥� These things are exterior to a man but style is the man himself.鈥�
鈥淎 fine adventure story, to be devoured by the maidservant and amuse the lackey鈥�
Despite his confidence, the perception of Buffon as a phrasemonger did not help his later reputation, nor did his dismissal of Carl Linnaeus鈥檚 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鈥檚. 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鈥檚 something to be celebrated in any era.
This article appeared in print under the headline 鈥淓arth will freeze if we don鈥檛 step in鈥�
