Buffon's Epochs of Nature

Buffon
comte de Buffon

George Louis Leclerc, comte de Buffon (1707-1788) was the leading naturalist of the 18th century. His masterwork, Historie naturelle , was a multi-volume effort to encompass the whole of Nature (1), and was regarded as the source for information on the natural world. His audience was wide and influential, and he was in an ideal position to have an enduring influence on European thought. With Des époques de la nature (The Epochs of Nature), first published in 1788 as a supplementary volume of Histoire naturalle, Buffon presented them with a natural world that had a history (2).

Epochs of Nature endeavored to explain a number of perplexing "facts." One of these was the presence of "elephants" in the frigid North (3). Another was the widely reported presence of seashells on mountaintops. And Buffon, more than anyone else, was familiar with some striking biogeographic patterns. The fauna of North America and temperate Eurasia were remarkably similar, while South America was host to many unusual forms.

A crucial concept in Epochs of Nature was that Earth's internal heat had a significant impact on climate. The impetus for this concept apparently came from a 1765 memoir by Dortous de Mairan in which it was demonstrated that winters in the Temperate Zone would be much colder if solar radiation was the only source of heat. Buffon believed that heat from the interior of the Earth provided the additional warmth, but he rejected a widely held notion that it originated from an "internal fire." Instead, he held that the internal heat of the Earth was residual. The Earth was slowly cooling down from a fiery birth.

antique map
Arctic projection map
(after Buffon, 1778)

Buffon realized by 1767 that if the Earth started as a globe of molten matter, then a combination of experimentation and calculation could provide a reasonable estimate of its age. Thus he began an extensive series of experiments in his forge using spheres of differing sizes and compositions, and measureing the time it took for white-hot spheres to cool enough to be touched. Extrapolating from the results, he calculated that the Earth required about 34,000 years of cooling before it could support life (i.e., before it could be touched without burning) and about 75,000 years (actually 74,832 years) before it reached its current temperature (4).

Armed with what he regarded as a reasonable representation of a cooling Earth, Buffon constructed a historical narrative with seven epochs. The First Epoch dealt with the formation of the earth via a cometary impact (5). The consolidation of the interior of the Earth into solid rock and the formation of its surface minerals constitute the Second Epoch. A universal ocean covered most of the globe during the Third Epoch and its retreat marked the Fourth.

Some of the details for the second, third and fourth epochs were inspired during Buffon's experiments with the heated globes. Incidental observations of the cooling globes revealed some interesting surface features. Minute ridges spontaneously formed on the surface while small air pockets formed beneath. Scaled to the size of the Earth, the minute ridges would become massive mountain ranges and the pockets would become vast subterranean caverns. Buffon reasoned that both of these geologic features would form during the Second Epoch.

marine fossils
Cretaceous marine
invertebrates
(after Morton, 1834)

Buffon also reasoned that the initial cooling of the Earth would result in cycles of volatilization and condensation that would ultimately result in the creation of the Third Epoch's universal ocean. This vast body of water would have covered everything but the highest peaks, and its arrival would also mark the beginning of life. A universal ocean could explain the presence of marine fossils on all but the highest mountains (f6). It would also explain the frequent occurrence of sedimentary rock in upland areas. This epoch came to a catastrophic end when violent volcanic activity opened up the vast underground caverns. The waters rushed in and all but a fraction of the great ocean was lost.

The retreat of the universal ocean resulted in the emergence of the continents and marked the beginning of the Fifth Epoch, which Buffon titled "Lorsque les Elephas & les autre Annimaus du Midi ont habite les terres du Nord" (When the elephants and other animals of the Tropics inhabit the North). Here he elaborated on two significant elements of his history: the role of heat in the creation of life; and the influence of latitude on global cooling.

The influence of latitude was based on the shape of the Earth as predicted by Isaac Newton. Although commonly conceived as a sphere, the centrifugal force generated by its rotation means that the Earth would actually be wider at the Equator than it would be from pole to pole. This "flattening at the poles" led Buffon to concluded that the loss of internal heat was greater there. Accordingly, cooling would occur first at the poles and later progress towards the Equator.

elephant horse and reindeer
Elephant, horse
and reindeer
(after Histoire naturalle)

Buffon was rather vague on how species originated. He wrote of "organic molecules" that —under the right conditions— spontaneously organized themselves into complex organisms such as birds or quadrupeds (four-legged vertebrates). He did, however, emphasize the importance of heat in the creation. Too much heat prevented it, while too little heat enfeebled it. Consequently, Buffon envisioned the Far North as the cradle of creation because that is where ideal conditions first arise. At critical times, new life would form in this cradle. But as cooling progressed from the poles to the Equator, the fruits of creation would be driven to the warmer, lower latitudes.

Since heat was a vital force in the creation of new species. Buffon reasoned that species that arose earlier were more vigorous. This certainly seemed to apply to the Ohio animal (American mastodon) and the Siberian mammoth (woolly mammoth) whose remains were widely believed to be substantally larger than their modern counterparts (7):

"Nature was in her first vigor; the internal heat of the earth gave her productions all the energy and the range of which they were capable." (8)

Buffon conceived of multiple creations, all of which occurred in the Far North. With cooling the new species would migrate to warmer climes. Those currently found in the Torrid Zone (The Tropics) arose in the North earlier than those now found in the Temperate Zone. As for those currently occupying the North, he envisioned a time when they too would move South, and in their place there might be a new creation:

"And who knows if with the passage of time, when the Earth will be cooler, new species will not appear, whose constitution will differ from that of the reindeer as much as the nature of the reindeer differs in that respect from that of the elephant?"

The continents of Buffon's Fifth Epoch were interconnected. This geographic configuration would explain why the faunas of North American and Eurasian faunas were similar. South America, on the other hand, hosted a largely unique fauna. Moreover, although much of it lay in the Tropics, it lacked the impressively large animals found in the Tropics of the Old World (9). Buffon contented that it had always been connected to North America via Panama, but the mountains of that isthmus proved an effective barrier to the immigration from the North. Thus isolated, South America was "reduced to its own forces." and "gave birth to only weaker and much smaller animals than those which came from the North to populate our regions of the South."

mastodon molar
Molar of the Ohio animal
(after Buffon, 1778)

This supposed barrier at Panama would have dire consequences for the "Ohio animal" (American mastodon), a mysterious giant of a quadruped whose identity eluded Europe's leading naturalists. Unable to traverse the Panamanian mountains, it would perish (10). This contention was notable given that the belief in extinction was still a minority position among 18th century naturalists (11). Far more striking —and dire— was Buffon's prediction that further global cooling would inevitably result in the extinction of all life on the planet.

The Sixth Epoch marks the violent separation of the continents. The Seventh (and last) Epoch is primarily concerned with the transformation of the Earth by Man. Buffon believed that human activity could greatly improve the earth and significantly delay the inevitable freeze: "Cleansing, clearing, and populating a country gives it heat for several thousand years." As evidence, he cited the contrast between the wholesome climate found in the cultivated countryside surrounding Paris with the frigid wilderness of Quebec.

Epochs of Nature sought to explain a multitude of mysteries through a grand narrative. Seashells on mountaintops were deposited by a universal ocean. Elephants once lived in the formerly torrid North. Paris is bountiful because of the hand of Man. And all of Nature is directed by the cooling over thousands of centuries of what was once an incandescent globe. Buffon's essay was praised, criticized, and condemned. Theologians at the Sorbonne forced him to issue an retraction but this ultimately proved inconsequential (12), and in a bizarre episode, Catherine the Great lavished praise and gifts upon Buffon for proclaiming Russia the cradle of life. The response among his scientific peers was typically more restrained. They might criticize a particular element, such as the role of a comet in forming the Earth, but they might also praise the overall story. On the other hand, science (and natural history) in the late 18th century was transforming itself. Grand stories explaining everything were falling out of fashion. The new science tended to focus on more manageable and particular issues.

Nonetheless, Buffon's Epochs left its mark. He popularized the notion of a long, pre-human past (i.e., deep time), that was vastly different from our own. In addition, he advocated the use of natural rather than supernatural explantions. Most significantly, he employed a new tool for organizing and understanding Nature: its history.

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Websites:

  1. Kurt Stuber's online version of Epochen der Natur (1781 German Edition of Epochs of Nature):
    caliban.mpiz-koeln.mpg.de/~stueber/buffon/epochen/index.html
  2. Fran Moran's page on Buffon's "The Theory of the Earth":
    faculty.njcu.edu/fmoran/vol1art1.htm
  3. Fran Moran's page on Buffon's "On the Formation of the Planets":
    faculty.njcu.edu/fmoran/vol1art2.htm

Print Resources:

  1. Buffon, Georges Louis LeClerc, Comte de. 1749-1788. Histoire naturelle, générale et particulière. Paris: Imprimeries royale.
  2. Buffon, Georges Louis LeClerc, Comte de. 1778. "Des époques de la nature." in: Histoire naturelle, générale et particulière. Supplement vol V. Paris: Imprimeries royale.
  3. Cohen, C. 2002. The Fate of the Mammoth: Fossils, Myths and History. Translated by William Rodarmor. Chicago: University of Chicago Press. Originally published as Le Destin du Mammouth. 1994. Editions du Seuil.
  4. Gould, S.J. 2000. "Inventing Natural History in Style: Buffon's Style and Substance." pp. 75-90. In: The Lying Stones of Marrakech: Penultimate Reflections in Natural History. New York: Harmony Books.
  5. Mayr, E. 1982. The Growth of Biological Thought: Diversity, Evolution, and Inheritance. Cambridge & London: Harvard University Press.
  6. Morton, Samuel George. 1834. Synopsis of the Organic Remains of the Cretaceous Group of the United States. Philadelphia: Key & Biddle.
  7. Roger, J. 1997. Buffon: a Life in Natural History. Translated by S. Lucille. Edited by L.P. Williams. Ithaca: Cornell University Press. Originally published as Buffon, un philosophe au Jardin du Roi. 1989. Librairie Artheme Fayard.
  8. Semonin, P. 2002. American Monster: How the nation's first prehistoric creature became a symbol of national identity. New York & London: New York University Press.

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Notes:

  1. A total of 36 volumes of Historie naturelle (Natural History) were published during Buffon's lifetime and another eight volumes were completed and published after his death. Conceived as a comprehensive study of the whole of Nature, this series contained essays concerning embryology, physiology, biogeography, domestication, human biology, classification, behavior, geology, the origin of life, reproduction and nutrition. In addition, it presented numerous essays on particular species of viviparous quadrupeds (four-legged mammals), birds and types of minerals. This massive publication was widely considered to be an essential part of any educated person's library. [go back]
  2. The study of nature put little emphasis on history prior to the publication of Epochs of Nature. If they considered the past at all, naturalists would typically either adopt their ideas from Genesis or propose indeterminate cycles of mountain building and erosion. Adherents of Genesis would present an Earth only a few thousands years old that —outside of human events— was altered only by the Flood. The idea of endless —or indeterminate— geological cycles had its origin in the Ancient Greek concept of time. Some naturalists adopted it in response to their observations on sedimentary strata. They proposed an immense age for the earth because such immense deposits required more than a few thousand years to accumulate.

    The use of history as an organizing principle for understanding Nature was arguably an inevitable development in Western science; three geological pioneers, James Hutton (1726-1797), Abraham Werner (1749-1817) and William Smith (1769-1839) were either developing or espousing their ideas of geological history when Epochs was published. However, Buffon's encyclopedic scope, accessible writing style and avid readership would make the greatest immediate impact. [go back]
  3. Fossils of the American mastodon had been discovered in the Ohio Valley of North America and those of woolly mammoths were known from Siberia. The distinctive tusks of these extinct animals led many 18th century naturalists to identify them as elephants. These fossils were not seen as particularly old since they were either recovered from frozen carcasses, from the surface of the ground or were shallowly buried in loose, surficial deposits. See Discovering the Mastodon: part 2-Enter the French and About the Woolly Mammoth for more information. [go back]
  4. Soon after he arrived at his estimate of 74,832 years, Buffon realized that it was far too short. Empirical studies of sedimentation exceeded the approximately 34,000 years allotted for life on Earth. Revisions of his calculations and their underlying assumptions resulted in several upwardly revised estimates in the hundred of thousands and even millions of years. But Buffon may have realized he was on shaky ground and stuck with the estimate of 74,832 years. He regarded this as a conservative, but more rigorous estimate.

    Buffon's estimate of 75,000 years is far short of the billions of years we now assign to the age of the Earth, but it was a stark departure from the approximately 4,000 year biblically-derived chronology. On the other hand, a few geologists in the late 18th century were proposing the passage of hundreds or even thousands of centuries to account for what they saw in geologic strata. [go back]
  5. Buffon first proposed a fiery origin for the earth in the first (1749) volume of Historie naturelle. In an essay titled "De la formation des planètes" (On the Formation of the Planets), he wrote that the Earth and the other planets were formed when wayward comets obliquely struck the sun. The impacts tore of fragments and imparted onto them a spin. Over time, these fiery fragments would solidify and cool, but retain their spin (rotation).

    Buffon again invoked cometary impacts in Epochs of Nature. Back in 1749, comets were widely believed to be massive and dense bodies capable of dislodging fragments from the sun. By 1778, however, astronomical observations convinced many authorities that comets lacked such mass. They strongly criticized Buffon's impact theory, but it probably didn't matter that much to Buffon. Instead, it was that the Earth retained residual heat. [go back]
  6. With the exception of a few Pleistocene mammals, such as the Ohio animal (American mastodon) and the Siberian elephant (woolly mammoth), and plant fragments embedded in coal, the fossils familiar to Buffon's contemporaries consisted of either marine fishes or —most commonly— marine invertebrates; dinosaurs and marine reptiles had yet to be discovered. Even today, marine invertebrates account for most of the fossils collected. They do so for a combination of reasons. One is that readily fossilized organisms thrived in the oceans long before they lived on land. Another is that fossilization most readily occurs under water. In fact, almost all of the terrestrial fossils actually formed in freshwater, estuarine or nearshore marine settings. Finally, seawater is rich in calcium, a mineral used by many marine invertebrates for their shells (e.g., mollusks and brachiopods) or skeletons (e.g., crinoids and trilobites). These mineralized hard parts are readily fossilized. [go back]
  7. Although later discoveries would prove them wrong, European naturalists of the 18th century believed that the Ohio animal (American mastodon) and the Siberian mammoth (woolly mammoth) were substantially larger than contemporary elephants. This was entirely reasonable, given the fragmentary remains they had at their disposal. These fossils typically consisted of isolated bones, teeth or tusks. A mammoth tusk can reach a length of 13.5 ft. (4.2 m), which is considerably longer that the length of both the Indian and African elephants, while its leg bone was slightly longer. Although not as long as those of the mammoth, the mastodon's tusks were often larger than those of the Indian elephant, while its leg bones were dramatically more heavily built. Moreover, European knowledge of modern elephants was seriously limited. For instance, they widely regarded the Indian and African elephants as members of the same species until Georges Cuvier's demonstrated otherwise in 1796. [go back]
  8. Translations are from Roger (1997) and Cohen (2000). [go back]
  9. Buffon had discussed the unusual South American fauna in earlier volumes of Histoire naturalle. He also discussed the North American fauna, which he regarded as a degenerate version of that from Eurasia. At the time, he attributed the "inferiority" of the New World fauna to a cold and excessively humid climate. (See American Degeneracy Part 1: Old World vs. New for more information.) Buffon has largely discarded his ideas about degeneracy by the time he worked on Epochs of Nature. He did, however, continue to maintain the inferior nature of the South American fauna. He concluded that since it was isolated from the northern cradle of creation that produced mighty giants such as the elephant and rhinoceros, if could only produce inferior versions such as the tapir and anteater. [go back]
  10. Buffon's erroneous contention that the "cold" mountains of Panama presented an impassible barrier for the "Ohio animal" clearly demonstrates his tendency to make bold claims based on incomplete information. In fact, a variety of proboscidians (a diverse group of large mammals related to elephants and the American mastodon) colonized South America during the Great American Interchange. This event, which occurred during the late Pliocene and Pleistocene, is the greatest known interchange between two previously separated faunas: South America and Eurasian-influenced North America. Some of the interchange occurred via island hopping in the Caribbean but most of it was made possible by the newly formed isthmus at Panama that connected the two continents. See Tom Gidwitz's web pages on the Great American Interchange (www.tomgidwitz.com/main/id80.htm) for more information. [go back]
  11. Buffon's contention that the Ohio animal was "un espèce perdue" (lost or extinct species) wasn't the first scholarly claim for an extinct species. For instance, William Hunter declared the same animal (he called it the American incognitum) extinct in 1768. Buffon himself had stated that some marine fossils such as the ammonites and belemnites (cephalopod mollusks common in the Mesozoic) must be extinct in "Théorie de la terre" (Theory of the Earth), an essay he published in 1749. Nonetheless, Buffon's 1778 contention lent significant credibility to the idea of extinction. See Fossils and Extinction for more information. [go back]
  12. Buffon has a long and contentious relationship with the religious establishment in Paris. His struggles started with the first volume of Histoire naturelle, which was published in 1749. The essay in question, "Théorie de la terre" (Theory of the Earth), reported that the Earth had a long and cyclical history of gradual erosion and continental exposure driven by natural processes. This divergence from the story in Genesis prompted the Theological Faculty of the Sorbonne to condemn the essay and demand a retraction. Buffon obligingly wrote an "apology" and published it in all subsequent volumes of Histoire naturelle. Apparently most readers didn't take Buffon's apology seriously, nor did Buffon remove the offending essay.

    Epochs of Nature, which represented an even more serious divergence from Genesis, prompted a new response by the Sorbonne. By this time, however, Buffon's stature had increased substantially. He consented to sign a new retraction and promised to publish it in subsequent volumes. The promise was never fulfilled, but his retraction was made public in a Latin brochure released by the Sorbonne. It was quickly forgotten while Epochs of Nature underwent multiple editions and several translations. [go back)

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