Marie Skłodowska-Curie (November 7, 1867 – July 4, 1934)

Marie Curie, née Maria Sklodowska, was born in Warsaw on November 7, 1867, the daughter of a secondary-school teacher. She received a general education in local schools and some scientific training from her father. She became involved in a students' revolutionary organization and found it prudent to leave Warsaw, then in the part of Poland dominated by Russia, for Cracow, which at that time was under Austrian rule. In 1891, she went to Paris to continue her studies at the Sorbonne where she obtained Licenciateships in Physics and the Mathematical Sciences. She met Pierre Curie, Professor in the School of Physics, in 1894 and in the following year they were married. She succeeded her husband as Head of the Physics Laboratory at the Sorbonne, gained her Doctor of Science degree in 1903, and following the tragic death of Pierre Curie in 1906, she took his place as Professor of General Physics in the Faculty of Sciences, the first time a woman had held this position. She was also appointed Director of the Curie Laboratory in the Radium Institute of the University of Paris, founded in 1914.

Her early researches, together with her husband, were often performed under difficult conditions, laboratory arrangements were poor and both had to undertake much teaching to earn a livelihood. The discovery of radioactivity by Henri Becquerel in 1896 inspired the Curies in their brilliant researches and analyses which led to the isolation of polonium, named after the country of Marie's birth, and radium. Mme. Curie developed methods for the separation of radium from radioactive residues in sufficient quantities to allow for its characterization and the careful study of its properties, therapeutic properties in particular.

Mme. Curie throughout her life actively promoted the use of radium to alleviate suffering and during World War I, assisted by her daughter, Iréne, she personally devoted herself to this remedial work. She retained her enthusiasm for science throughout her life and did much to establish a radioactivity laboratory in her native city - in 1929 President Hoover of the United States presented her with a gift of $50,000 donated by American friends of science, to purchase radium for use in the laboratory in Warsaw.

Mme. Curie, quiet, dignified and unassuming, was held in high esteem and admiration by scientists throughout the world. She was a member of the Conseil du Physique Solvay from 1911 until her death and since 1922 she had been a member of the Committee of Intellectual Co-operation of the League of Nations. Her work is recorded in numerous papers in scientific journals and she is the author of Recherches sur les Substances Radioactives (Investigations on radioactive substances) (1904), L'Isotopie et les Eléments Isotopes (Isotopy and isotopic elements) and the classic Traité de radioactivité (Treatise on radioactivity) (1910).

The importance of Mme. Curie's work is reflected in the numerous awards bestowed on her. She received many honorary science, medicine and law degrees and honorary memberships of learned societies throughout the world. Together with her husband, she was awarded half of the Nobel Prize for Physics in 1903, for their study into the spontaneous radiation discovered by Becquerel, who was awarded the other half of the Prize. In 1911 she received a second Nobel Prize, this time in Chemistry, in recognition of her work in radioactivity. She also received, jointly with her husband, the Davy Medal of the Royal Society in 1903 and, in 1921, President Harding of the United States, on behalf of the women of America, presented her with one gram of radium in recognition of her service to science.

The Curie's elder daughter, Iréne, married Frédéric Joliot in 1926 and they were joint recipients of the Nobel Prize for Chemistry in 1935. The younger daughter, Eve, married the American diplomat H.R. Labouisse. They have both taken lively interest in social problems, and as Director of the United Nations' Children's Fund he received on its behalf the Nobel Peace Prize in Oslo in 1965. She is the author of a famous biography of her mother, Madame Curie (Gallimard, Paris, 1938), translated into several languages.

Mme. Curie died in Savoy, France, after a short illness, on July 4, 1934.

Williamina Paton Stevens Fleming (May 15, 1857 – May 21, 1911)

Williamina was a scottish astronomer born in 1857 in Dundee, where she also attended public schools. When she was 21 she moved to Boston with her husband, and fell pregnant. However, her husband abandoned her and she had to seek work to support herself and her new son, Edward.

She became a maid in the home of Professor Edward Charles Pickering, who ran the Harvard College Observatory. He famously stated that he was frustrated with his male assistants and that his maid, Williamina, was capable of doing a better job. Thus, she was employed to do clerical work at the observatory. She soon demonstrated her flare for astronomy and devised a system to classify stars according to how much hydrogen they displayed in their spectra. She also contributed to the cataloguing of stars that would be published as the Henry Draper Catalogue, and in nine years she catalogued over 10,000 stars as well as discovering 59 gaseous nebulae, 310 variable stars and 10 novae. She also discovered the Horsehead nebula on a photographic plate taken by William Pickering.

In 1899, Williamina had proved herself to the extent that she became Curator of Astronomical Photographs at Harvard, and was placed in charge of dozens of other women hired to perform star counts and classifications. In 1906 she became the first American women to be given hononary membership to the Royal Astronomical Society of London. She was also awarded the Guadalupe Alemndaro medal by the Astronomical Society of Mexico for her discovery of new stars. She published A Photographic Study of Variable Stars  in 1907 and Spectra and Photographic Magnitudes of Stars in Standard Regions in 1911.

She died of pneumonia at the age of 54. She has the crater Fleming named jointly for her and Alexander Fleming.

Antonia Maury (March 21, 1866–January 8, 1952)

American born Antonia Maury came from a family with a distinguished scientific background. She was a cousin of Matthew Maury, the oceanographer, a niece of Henry Draper, the physician and astronomer after whom the Harvard star catalogue was named, her sister became a paleontologist, while her father, a clergyman, was also a well-known naturalist.

Maury was educated at Vassar and graduated in 1887; two years later she became an assistant to Edward Pickering at Harvard College Observatory, as well as lecturing at various eastern colleges between 1899 and 1908. Her first assignment for Pickering was to determine the orbital period of the spectroscopic binary Zeta Ursae Majoris, also called Mizar, which was first discovered by Pickering in 1887. Maury independently discovered the second binary, Beta Aurigae and determined its orbital period.

Maury also did a lot of work on spectra, and around the same time that Cannon was revising the system of spectral classification of stars, Maury proposed an additional modification. She argued that not just the absence or presence of a particular spectral line was important, but also its appearance.

Within Cannon’s system, Maury noticed that two stars having the same pattern of lines and colour were also displaying differences in line width and sharpness. She therefore introduced three further subdivisions that recognised these features. She marked stars with normal lines ‘a’, those with hazy lines ‘b’, and those that were sharp, ‘c’; intermediate cases were marked ‘ab’ or ‘ac’. This has been described as the first step in using spectroscopic criteria for the luminosities of stars. However, the system was ignored by her Harvard contemporaries as being too cumbersome, and brought her into direct conflict with Pickering, forcing her to temporarily leave the project in 1892.

Even having left the Observatory, Pickering urged her to complete her work or else hand it over to someone else. Maury demanded to be acknowledged as the author of her work, a gesture commonly denied to women scientists. After much conflict, she eventually got her way, and her catalogue of over 600 stars appeared in volume 28 of the Harvard Annals in 1897, and was the first issue to have the name of a woman on the title page.

Although Pickering continued to downplay the importance of Maury's work,  one person, Ejnar Hertzsprung was quick to see the significance of her classification system and in 1905 pointed out that c-type and ac-type stars were brighter than a- or b-type stars. Of all the catalogues published, only Maury's classification provided the distinction that he was looking for. Maury's work was vital in Hertzprung's formulation which came to be known as the Hertzprung-Russel diagram. Her contribution to spectral analysis was finally acknowledged in 1922 when the International Astronomical Union modified its official classification system based on Annie Cannon's system to include the prefix c-to a certain spectral type defined by narrow and sharp lines.

Although Maury did not return to Harvard for over a decade after the publication of her catalogue, she continued to research spectroscopic binary stars. She turned her attention to the complex spectroscopic binary, Beta Lyrae, and publishing her conclusions based on over 300 spectra of the star in a treatise in the Harvard Annals in 1933.

Henrietta Swan Leavitt, (July 4, 1868—December 12, 1921)

Henrietta Leavitt, American astronomer known for her discovery of the relationship between period and luminosity in Cepheid variables, pulsating stars that vary regularly in brightness in periods ranging from a few days to several months.

Leavitt attended Oberlin College for two years (1886–88) and then transferred to the Society for the Collegiate Instruction of Women (later Radcliffe College), from which she graduated in 1892. Following an interest aroused in her senior year, she became a volunteer assistant in the Harvard Observatory in 1895. In 1902 she received a permanent staff appointment. From the outset she was employed in the observatory’s great project, begun by Edward C. Pickering, of determining the brightnesses of all measurable stars. In this work she was associated with the older Williamina Fleming and the more nearly contemporary Annie Jump Cannon. Pickering's staff, being primarilly made up of women, became known as "Pickering's Harem" or "Pickering's Computers".

Leavitt soon advanced from routine work to a position as head of the photographic stellar photometry department. A new phase of the work began in 1907 with Pickering’s ambitious plan to ascertain photographically standardized values for stellar magnitudes. The vastly increased accuracy permitted by photographic techniques, which unlike the subjective eye were not misled by the different colours of the stars, depended upon the establishment of a basic sequence of standard magnitudes for comparison. The problem was given to Leavitt, who began with a sequence of 46 stars in the vicinity of the north celestial pole. Devising new methods of analysis, she determined their magnitudes and then those of a much larger sample in the same region, extending the scale of standard brightnesses down to the 21st magnitude. These standards were published in 1912 and 1917.

She then established secondary standard sequences of from 15 to 22 reference stars in each of 48 selected “Harvard Standard Regions” of the sky, using photographs supplied by observatories around the world. Her North Polar Sequence was adopted for the Astrographic Map of the Sky, an international project undertaken in 1913, and by the time of her death she had completely determined magnitudes for stars in 108 areas of the sky. Her system remained in general use until improved technology made possible photoelectrical measurements of far greater accuracy. One result of her work on stellar magnitudes was her discovery of 4 novas and some 2,400 variable stars, the latter figure comprising more than half of all those known even by 1930. Leavitt continued her work at the Harvard Observatory until her death.

Leavitt’s outstanding achievement was her discovery in 1912 that in a certain class of variable stars, the Cepheid variables, the period of the cycle of fluctuation in brightness is highly regular and is determined by the actual luminosity of the star. The subsequent calibration of the period-luminosity curve allowed American astronomers Edwin Hubble, Harlow Shapley, and others to determine the distances of many Cepheid stars and consequently of the star clusters and galaxies in which they were observed. The most dramatic application was Hubble’s use in 1924 of a Cepheid variable to determine the distance to the great nebula in Andromeda, which was the first distance measurement for a galaxy outside the Milky Way. Although it was later discovered that there are actually two different types of Cepheid variable, the same method can still be applied separately to each type.

Annie Jump Cannon (December 11, 1863 – April 13, 1941)

Oh, Be A Fine Girl--Kiss Me! 

This phrase has helped several generations of astronomers to learn the spectral classifications of stars. Ironically, this mnemonic device, still used today, refers to a scheme developed by a woman.

Annie Jump Cannon was the eldest of three daughters of Wilson Cannon, a Delaware shipbuilder and state senator, and his second wife, Mary Jump. Annie's mother taught her the constellations and stimulated her interest in astronomy. At Wellesley, Annie studied physics and astronomy and learned to make spectroscopic measurements. On her graduation in 1884, she returned to Delaware for a decade, but became impatient to get back to astronomy. After the death of her mother in 1894, Cannon worked at Wellesley as a junior physics teacher and became a "special student" of astronomy at Radcliffe.

In 1896, she became a member of the group that historians of science have dubbed "Pickering's Women," women hired by Harvard College Observatory director Edward Pickering to reduce data and carry out astronomical calculations. Pickering's approach to science was thoroughly Baconian: "the first step is to accumulate the facts."* The accumulating was supported by a fund set up in 1886 by Anna Draper, widow of Henry Draper, a wealthy physician and amateur astronomer.

Pickering conceived the Henry Draper Memorial as a long-term project to obtain optical spectra of as many stars as possible and to index and classify stars by their spectra. While the measurements were difficult enough, the development of a reasonable classification scheme proved as much a problem in "theory" (which Pickering was slow to recognize) as "fact accumulation."

The analysis was begun in 1886 by Nettie Farrar, who left after a few months to be married. Her place was taken by Williamina Fleming, the first of Pickering's female crew to be recognized in the astronomical community at large. Fleming examined the spectra of more than 10,000 stars and developed a classification system containing 22 classes. The work was carried further by Antonia Maury, who developed her own classification system. The system was cumbersome by comparison with Fleming's, and Pickering could not sympathize with Maury's insistence on theoretical (what we would today call astrophysical) concerns that underlay her scheme.

It was left to Annie Jump Cannon to continue, beginning with an examination of bright southern hemisphere stars. To these she applied yet a third scheme, derived from Fleming's and Maury's, an "arbitrary" division of stars into the spectral classes O, B, A, F, G, K, M, and so on. It was as "theory-laden" as Maury's ordering, but greatly simplified. Her "eye" for stellar spectra was phenomenal, and her Draper catalogs (which ultimately listed nearly 400,000 stars) were valued as the work of a single observer.

Cannon also published catalogs of variable stars (including 300 she discovered). Her career spanned more than forty years, during which women in science won grudging acceptance. She received many "firsts" (first recipient of an honorary doctorate from Oxford, first woman elected an officer of the American Astronomical Society, etc.). At Harvard she was named Curator of Astronomical Photographs, but it was only in 1938, two years before her retirement, that she obtained a regular Harvard appointment as William C. Bond Astronomer.

Florence Bascom (July 14, 1862 – June 18, 1945)

Florence Bascom collected many “firsts” in her geological career: she was the first woman to receive a Ph.D. from Johns Hopkins University (sitting behind a screen so the male students wouldn’t know she was there); the first woman geologist hired by the USGS; the first woman to present a scientific paper at the Geological Society of Washington; and the first woman officer of the Geological Society of America.

Bascom was born in 1862 in Williamstown, Mass., and died in Northampton 83 years later. Her father, president first of Williams College and later of the University of Wisconsin, encouraged her interest in geology, and she went on to earn bachelor’s and master’s degrees in geology from the University of Wisconsin in the 1880s.Her professors at Wisconsin, Roland Irving and Charles Van Hise, were also employed by the USGS, as was her professor at Johns Hopkins, George Williams. After receiving her Ph.D. in 1893, she began teaching geology at Bryn Mawr College (the first women’s college to offer graduate education through the Ph.D), but she combined her teaching career with active field and laboratory work for the USGS.She was an authority on the rocks of the Piedmont and published maps and folios. She also studied water resources of the Philadelphia region. Her writing was vigorous and incisive; her conversation was forceful and clear, if sometimes caustic.

Bascom later developed the geology curriculum at Bryn Mawr from a single course to a full major and then to a graduate program which trained most American women geologists during the first third of the 20th century. At least three of her students later joined the USGS. Bascom retired from teaching in 1928 but continued to work for the USGS until 1936.

Peter Lyttle, current program coordinator for USGS national cooperative geologic mapping and landslide hazards, recounts a distant but clear connection to Florence Bascom:

“When I was mapping in the Piedmont near Philadelphia in the 1980′s, I was hammering away at an outcrop on the side of the road.  An elderly gentleman driving by saw me and parked his car so that he could talk to me. It was common for people to stop and ask me what I was up to, and I had my usual reply ready. His comment, however, was not one that I was expecting. He had already figured out that I was a geologist, and he angrily asked me why I was remapping an area already mapped by Florence Bascom. Fortunately, I was able to pull out a copy of Bascom’s 1909 USGS folio of the Philadelphia area and explain that, indeed, I was benefiting from her fantastic work. I assured the gentleman that I properly understood the role that Dr. Bascom had played in field of geology and appreciated that I was standing on the shoulders of a giant. He went away mollified, if not happy.”

Clarissa Harlowe "Clara" Barton (December 25, 1821 – April 12, 1912)

Clara Barton was born on December 25, 1821, in Oxford, Massachusetts. She became a teacher, worked in the U.S. Patent Office and was an independent nurse during the Civil War. While visiting Europe, she worked with a relief organization known as the International Red Cross, and lobbied for an American branch when she returned home. The American Red Cross was founded in 1881, and Barton served as its first president.

Early Life
Educator, nurse and founder of the American Red Cross Clara Barton was born Clarissa Harlowe Barton on December 25, 1821, in Oxford, Massachusetts. Barton spent much of her life in the service of others and created an organization that still helps people in need today -- the American Red Cross.

A shy child, she first found her calling when she tended to her brother David after an accident. Barton later found another outlet for her desire to be helpful as a teenager. She became a teacher at age 15 and later opened a free public school in New Jersey. She moved to Washington, D.C., to work in the U.S. Patent Office as a clerk in the mid-1850s.

'Angel of the Battlefield'
During the Civil War, Clara Barton sought to help the soldiers in any way she could. At the beginning, she collected and distributed supplies for the Union Army. Not content sitting on the sidelines, Barton served as an independent nurse and first saw combat in Fredericksburg, Virginia, in 1862. She also cared for soldiers wounded at Antietam. Barton was nicknamed "the angel of the battlefield" for her work.

After the war ended in 1865, Clara Barton worked for the War Department, helping to either reunite missing soldiers and their families or find out more about those who were missing. She also became a lecturer and crowds of people came to hear her talk about her war experiences.

The American Red Cross
While visiting Europe, Clara Barton worked with a relief organization known as the International Red Cross during the Franco-Prussian War of 1870–'71. Some time after returning home to the United States, she began to lobby for an American branch of this international organization.

The American Red Cross Society was founded in 1881 and Barton served as its first president. As its leader, Clara Barton oversaw assistance and relief work for the victims of such disasters as the 1889 Johnstown Flood and the 1900 Galveston Flood.

Later Years and Death
Clara Barton resigned from the American Red Cross in 1904 amid an internal power struggle and claims of financial mismanagement. While she was known to be an autocratic leader, she never took a salary for her work within the organization and sometimes used her funds to support relief efforts.

After leaving the Red Cross, Clara Barton remained active, giving speeches and lectures. She also wrote a book entitled The Story of My Childhood, which was published in 1907. Barton died at her home in Glen Echo, Maryland, on April 12, 1912.