Eunice Newton Foote

• 1. Introduction

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  Eunice Newton Foote stood before no audience on the 23rd of August 1856, in Albany, New York. Her paper on the heat-trapping properties of atmospheric gases was presented at the tenth annual meeting of the American Association for the Advancement of Science, but not by her. A man read it on her behalf. That man, Joseph Henry of the Smithsonian Institution, opened by declaring that "science was of no country and of no sex" and then, in the pages of the New-York Daily Tribune, quietly discounted her findings as difficult to interpret. What Foote had actually discovered was nothing less than the foundational mechanism of what we now call the greenhouse effect. She had shown, years before anyone else, that carbon dioxide absorbs heat from sunlight, and that a rise in atmospheric carbon dioxide would warm the planet. She would die in 1888, and for nearly a hundred years, the world would forget she had ever done any of it.

• 2. A World Built for Questioning

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  Eunice Newton was born on the 17th of July 1819, in Goshen, Connecticut, to Thirza and Isaac Newton Jr. By 1820 the family had moved to Ontario County in western New York, where her father farmed and speculated, amassing and losing wealth along the way. He died in 1835, leaving a large family that included six sisters and five brothers. It was a fifth child, a daughter named Amanda, who stepped forward to clear the property's debts and keep the farm from being sold. The region where Eunice grew up was the era's center of social ferment. Abolitionists, temperance advocates, dress reformers, and women's rights campaigners were her neighbors and likely her earliest influences. That environment shaped not just her politics but her instinct to push against closed doors. She was a distant relative of the scientist Isaac Newton, a fact that carried a quiet symmetry. Her path to science began at the Troy Female Seminary, a pioneering institution founded by Emma Willard, whose sister Almira Hart Lincoln Phelps served as assistant principal and wrote the school's textbooks. Adjacent to the seminary sat the Rensselaer School, led by Amos Eaton, who believed women deserved a genuine scientific education and whose methods favored laboratory experimentation over rote learning. Newton attended both schools between 1836 and 1838, studying chemistry, meteorology, astronomy, and natural philosophy alongside languages, mathematics, and rhetoric.

• 3. Seneca Falls and the Declaration

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  On the 12th of August 1841, in East Bloomfield, Eunice Newton married Elisha Foote Jr., a lawyer who had trained under Judge Daniel Cady in Johnstown, New York. The connection to Cady was not incidental. Cady was the father of Elizabeth Cady Stanton, who would become Eunice's neighbor and a central figure in American suffrage. In 1844, Elisha bought, at a sheriff's sale, the house that the Stanton family would move into three years later; he then deeded it back to Daniel Cady, who in turn gave it to his daughter Elizabeth in 1846. The Footes settled in Seneca Falls, where Eunice became part of a tight circle of activists. Both she and Elisha signed the Declaration of Sentiments at the 1848 Seneca Falls Convention, the first gathering to treat women's rights as its sole purpose. The declaration, written by Stanton, demanded social and legal equality and the right to vote. Foote was one of five women who prepared the convention's proceedings for publication; the others were Stanton, Elizabeth M'Clintock, Mary Ann M'Clintock, and Amy Post. Elisha served as a judge at the Court of Common Pleas in Seneca County before resigning in 1846, then continued practicing law and eventually specializing in patent law. Eunice designed and built a laboratory in their home, which hints at the seriousness with which she treated her scientific work alongside her activism.

• 4. The Heat Experiment

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  Foote's 1856 experiment was simple by design and radical in its conclusions. She used an air pump, two glass cylinders, and four mercury-in-glass thermometers, placing two thermometers in each cylinder. She evacuated air from one cylinder and compressed it in the other, waited for both to reach equal ambient temperatures, and then exposed them to sunlight to measure how their temperatures diverged. She also tested the cylinders in shade as a control, and separately measured the effect of dry versus moist air by dehydrating one container and adding water to the other. She ran the same protocol on air, hydrogen, and carbon dioxide, which was called carbonic acid gas in her era. The cylinder filled with carbon dioxide became substantially hotter than the others and took far longer to cool after being removed from sunlight. Foote recorded that the gas reached a temperature of 125 degrees Fahrenheit. She then made a leap that connected her laboratory result to planetary history, writing that an atmosphere containing a larger proportion of carbon dioxide than at present "must have necessarily resulted" in an increased temperature for the Earth. The paper was published in the 1856 edition of the American Journal of Science and Arts under her own name, immediately following a paper by her husband. It was the first known physics publication in a scientific journal by an American woman, a distinction that would stand unchallenged until 1889. Scientific American praised her in its issue of the 13th of September 1856, noting that "she was deeply acquainted with almost every branch of physical science".

• 5. Carbon Dioxide, Then Static

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  By 1857, Foote had moved on to a new set of questions about static electricity in atmospheric gases. Her second paper, "On a New Source of Electrical Excitation", used an air pump connected to a sealed glass tube roughly two feet long and three inches in diameter. One end held a gold leaf electrometer to measure electrical charge, and the other attached to the pump. She cycled through oxygen, hydrogen, and carbon dioxide, as well as dry and damp air, expanding and compressing each to observe how pressure changes altered moisture content and, in turn, the capacity to generate static electricity. Her working hypothesis was that fluctuations in atmospheric pressure and electric charge might explain the Earth's magnetic polarity. That hypothesis was later shown to be incorrect by other scientists, but the measurements themselves were novel. Henry again read the paper at the annual AAAS conference, held in Montreal on the 14th of August 1857. In November of that year it was published in the Proceedings of the American Association for the Advancement of Science, marking the first time an American woman's work in physics had appeared in that journal. A New-York Daily Times article on the 18th of August 1857 praised her findings as "never heretofore proven", though in fact she had independently confirmed the ideal gas law of 1834, and had demonstrated adiabatic heating and cooling resulting from changes in pressure. During the nineteenth century, only sixteen physics papers in total were published by American women; the only two published before 1889 were Foote's.

• 6. Inventions Behind a Husband's Name

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  Science writing for Chemistry World, Rachel Brazil reported in 2020 that a thermostatically controlled cooking stove patented by Elisha in 1842 had in fact been invented by Eunice. The legal situation was clear and bleak: as a married woman, Eunice could not defend patents in court, so filing under her husband's name was a practical decision rather than a personal choice. Foote acknowledged the practice herself in 1868, when Elizabeth Cady Stanton visited her at the patent office. She told Stanton that in her view half of all patents filed were the work of women, but men controlled the money needed to build prototypes and sought the prestige, so they claimed the patents in their own names. In 1857, Elisha received a substantial settlement for infringement on that 1842 stove patent. Eunice did file some patents in her own name. In 1860 she patented a shoe and boot insert made from a single piece of vulcanized rubber to stop boots from squeaking. In 1864 she developed a new cylinder-type paper-making machine that a company from Fitchburg, Massachusetts later reported saved them $157 per day in raw materials. A skate she invented, designed without straps, was reported in The Emporia News in 1868. Her daughter Mary married John B. Henderson, a US Senator from Missouri and co-author of the 13th Amendment, in a lavish 1868 ceremony attended by President Andrew Johnson. Augusta married Francis Benjamin Arnold, a coffee importer from New York City, the following year.

• 7. Tyndall, Priority, and the Limits of Her Apparatus

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  John Tyndall published his first paper on the subject in 1859, reporting that several gases both trapped and emitted infrared thermal radiation. His equipment was more sophisticated than Foote's: he used a Leslie cube and a differential spectrometer. His seminal work on climate, "The Bakerian Lecture", was presented to the Royal Society in 1861 and published that year in the Philosophical Transactions of the Royal Society. For over a century, credit for discovering the greenhouse effect went to him. When scholars began comparing the two bodies of work, the dating was unambiguous. Roland Jackson, a visiting scholar at the Royal Institution in London, confirmed in 2019 that Foote's demonstration that water vapor and carbon dioxide absorb heat from sunlight preceded a similar claim by Tyndall by three years. Her observation that differing levels of water vapor and carbon dioxide in the atmosphere would affect climate preceded Tyndall's 1861 publication by five years. The question of whether Tyndall knew of Foote's paper has divided researchers. Physicist John Perlin argued that Tyndall likely did know, since one of his own papers appeared in the same 1856 volume of the American Journal of Science alongside Foote's. Jackson, who also wrote a biography of Tyndall, believes Tyndall probably never read her work. He noted that Foote's name appears in none of the correspondence, journals, or published papers of the critical physicists of her era. What modern analysis is clear about is the limit of Foote's apparatus: the glass walls of her vessels blocked longwave infrared radiation, meaning she measured a different process than the one that drives the greenhouse effect in a real atmosphere. She showed that carbon dioxide and water vapor absorb heat from sunlight, but she did not isolate or detect the absorption and emission of radiant energy in the thermal infrared range. Joseph D. Ortiz and Jackson, publishing their printed findings in 2022, nonetheless concluded that her results provided quantitative information about how greenhouse gases absorb and radiate heat.

• 8. Rediscovery and Legacy

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  Foote died on the 29th or the 30th of September 1888, in Lenox, Massachusetts, and was buried in Green-Wood Cemetery in Brooklyn, New York. For nearly a hundred years, her scientific contributions went unrecognized. In 1902, Susan B. Anthony named Foote alongside Elizabeth Cady Stanton and Lucretia Mott as a founder of the women's rights movement, but even that mention did not restore her scientific reputation. Women scholars began recovering her story in the 1970s. Historian Sally Gregory Kohlstedt noted Foote's participation at the 1857 AAAS meeting in a 1976 history of the organization. Lois Barber Arnold described her experiments in detail in 1984. Elizabeth Wagner Reed included a full chapter on Foote in her 1992 book American Women in Science Before the Civil War, the first to connect her work explicitly to what we now call the greenhouse effect. A wider audience found her through a 2011 article by retired petroleum geologist Ray Sorenson, published in an online journal of the American Association of Petroleum Geologists; Sorenson had discovered a summary of her work in an 1857 volume of The Annual of Scientific Discovery and eventually traced the full paper to the November 1856 issue of the American Journal of Science and Arts. Climate scientist Katharine Hayhoe, director of the Climate Science Center at Texas Tech University, published a Facebook article on Foote's story in 2016, followed shortly by a piece in Smithsonian magazine by Leila McNeill. In May 2018, the University of California, Santa Barbara hosted a symposium specifically organized to honor Foote, titled Science Knows No Gender: In Search of Eunice Foote Who 162 Years Ago Discovered the Principal Cause of Global Warming. A short film about her life, Eunice, was produced that year by Eric Garro and Paul Bancilhon. In 2022, the American Geophysical Union instituted The Eunice Newton Foote Medal for Earth-Life Science to recognize outstanding research at the convergence of Earth and life science. In 2025, the fossilized worm burrow ichnotaxon Osspecus eunicefooteae, found in Cretaceous deposits in the UK, was named in her honor.