Charlotte Elvira Pengra


Quick Info

Born
30 May 1875
Juda, Wisconsin, USA
Died
7 February 1916
Brodhead, Wisconsin, USA

Summary
Charlotte Pengra was the first woman to be awarded a Ph.D. in mathematics from the University of Wisconsin in 1901, making her the sixth American woman to receive a doctorate in mathematics

Biography

Charlotte Pengra was the daughter of Winfield Sherman Pengra (1847-1928) and Mary Ellen Preston (1853-1920). Winfield Pengra had been born on 2 November 1847 in Sylvester, Wisconsin. He married Mary Preston on 3 September 1874 in Juda, Wisconsin. Mary Ellen Preston had been born on 2 November 1853 in Jefferson, Green County, Wisconsin, the daughter of Nathaniel E Preston, born in England, and Charlotte Elizabeth Cook. Winfield and Mary Pengra had five children, Charlotte Elvira Pengra (1875-1916), the subject of this biography who was known as "Lottie", Mabel Agnes Pengra (1877-1936), Preston Winfield Pengra (1880-1910), Delia Idell Pengra (1882-1956), and Marshall Hylon Pengra (1885-1927). All five of these children studied at the University of Wisconsin and were awarded their degrees in 1887, 1899, 1902, 1904, and 1905, respectively. In 1880 the family were living in Jefferson, Wisconsin with Winfield Pengra's occupation being recorded as farmer. Later Winfield Pengra became a bank manager and a mayor. In 1900 the family were living in Madison, Wisconsin with Winfield Pengra's occupation being recorded as landlord. The family's address in Madison was 801 University Avenue, Madison, Wisconsin.

In 1893 Charlotte Pengra graduated from Madison High School and later that year she entered the University of Wisconsin. Her main interest was in mathematics and this would become her major subject. When Pengra entered the University of Wisconsin, Charles Ambrose Van Velzer (1851-1945) was Professor of Mathematics, Charles Sumner Slichter (1864-1946) was Professor of Applied Mathematics, Ernest Brown Skinner (1863-1935) was an Instructor in Mathematics, and Edward Burr Van Vleck (1863-1943) was an Instructor in Mathematics. Although Van Vleck was an Instructor at Madison only from 1893 to 1895, he left in 1895 but returned as a professor in 1906. Let us give a few more details concerning the other members of the mathematics faculty.

Charles Ambrose Van Velzer was born in Baldwinsville, New York, on 2 September 1851. He attended Cornell University from 1872 to 1876 when he graduated with a Bachelor of Science. He received first prize in mathematics at the intercollegiate contest in December of that year while he was an instructor at Cornell 1876-1877. He was a graduate fellow at Johns Hopkins University 1878-1881 and became Instructor in Mathematics at the University of Wisconsin in 1881. He was promoted to Assistant Professor in 1883 and to Professor in 1885. That was the same year, Hillsdale College conferred on him an honorary doctorate. Van Velzer served as Chair of the Department of Mathematics at the University of Wisconsin 1884-1894 and continued as a Professor at the University of Wisconsin until 1906. Charles Sumner Slichter was born in Saint Paul, Minnesota, on 16 April 1864. He attended Cornell University graduating with a Bachelor of Science in 1885. He then studied at Northwestern University, being awarded a Master's Degree in 1887. In 1886 he came to the University of Wisconsin as an instructor in mathematics, became an assistant professor in 1889, and in 1892 was made Professor of Applied Mathematics. He was appointed dean of the University of Wisconsin graduate school in 1920 and continued to hold that position until he retired in 1934. Ernest Brown Skinner (1863-1935) was born in Redfield, Ohio, on 12 December 1863. He graduated from Ohio University in 1888, taught at Amity College in Iowa (1888-1891), then undertook research at Clark University advised by William Story. In 1892, before completing work for a Ph.D., he came to the University of Wisconsin as an instructor and was promoted to assistant professor in 1895. He took leave for a year to undertake research for a Ph.D. at the University of Chicago which he was awarded in 1900. He was promoted to associate professor in 1910, and to a full professor in 1920. He continued as a Professor at the University of Wisconsin until his death in 1935.

In 1897 Pengra graduated with an honours B.S. degree having majored in mathematics with two minor subjects, economics and philosophy (see [12]). She wrote an excellent undergraduate thesis General rational fractional linear transformations of plane curves. After graduating she was appointed as a Teacher of Science at Fox Lake High School, in Fox Lake, Wisconsin. After a year in Fox Lake she moved to become a teacher at Sparta High School, in Sparta, Wisconsin. On 12 May 1899, she wrote from Sparta to Charles Slichter inquiring about a possible fellowship for graduate study at the University of Wisconsin. In the letter Pengra [9]:-
... indicated that she wanted a more complete college education for its own sake and because she would like to teach mathematics to students more advanced than in the high school. She indicated that she wanted to take a PhD, probably from Wisconsin, and that if she had the fellowship she would not teach again until she received the degree. Whereas the financial question was "not very pressing," she wrote that if she did not get the fellowship she would stay in Sparta.
Pengra was awarded the fellowship and later in 1899 she returned to the University of Wisconsin to begin undertaking research for a Ph.D. Now Linneaus Wayland Dowling had been appointed as an instructor in mathematics at the University of Wisconsin in 1895 in the middle of Pengra's undergraduate career. In 1898 he had been promoted to assistant professor of mathematics. He became Pengra's thesis advisor when she began her research in 1899. Dowling later became Florence Allen's thesis advisor and she gave this description of him in [2]:-
Professor Dowling's instruction was characterised by an exceptional clarity of exposition which, with his magnetism, geniality of manner, and interest in his students, made him a universally popular and beloved teacher. He was a man of unusual breadth of interests: a talented musician, an eager and well-informed botanist, and a student of the humanities. His knowledge of the language and literature of Italy, where he studied under the geometer Segre, was exceptional; and he was an ardent reader and lover of poetry. These talents explain, in part, the bonds of sympathy that united him with so many colleagues and students. But above all his attraction was due to his personal qualities, his cheerful disposition and his kindly character. His influence in these private associations was no less great than in his admirable public service as a teacher, and he will long be remembered and missed by his friends.
Pengra was an assistant in the Department of Mathematics at the University of Wisconsin from 1899 to 1901 when awarded her Ph.D. for her thesis On functions connected with special Riemann surfaces, in particular those for which p = 3, 4, and 5. Her thesis was published in 1904 as On the conformal representation of plane curves, particularly for the cases p = 4, 5, and 6 (see [10]).

During the year 1900-1901, Pengra met Arthur Robert Crathorne (1873-1946). He had been born on 26 October in Scarborough, Yorkshire, England to parents Francis R Crathorne and Anne Harrison. The family had emigrated to the United States in 1880. Arthur Crathorne had studied at the University of Illinois being awarded a B.S. in 1898. After graduating, he taught at the University of Maine (1898-1900) and was then appointed as an Instructor in Mathematics at the University of Wisconsin.

After the award of her Ph.D. in 1901, Pengra was appointed as Head of Mathematics at Elgin High School in Elgin, Illinois. She taught there for three years then, on Tuesday, 21 June 1904, she married Arthur Crathorne in Madison [1]:-
This afternoon at 4:00 o'clock at the residence of the parents, Mr and Mrs Winfield S Pengra, 803 University Avenue, Madison, was celebrated the marriage of Miss Charlotte E Pengra to Arthur R Crathorne.
Shortly after they married the young couple sailed from Montreal to Liverpool to have a holiday in England before continuing to Göttingen, Germany. In Göttingen, Arthur Crathorne studied under David Hilbert and wrote his 59-page doctoral thesis Das räumliche isoperimetrische Problem ; he was awarded his Ph.D. in 1907. Charlotte Crathorne attended mathematics classes in Göttingen until the birth of the couple's first child Mary Preston Crathorne (1906-1984) in Göttingen on 28 November 1906. On returning to the United States in 1907, Arthur Crathorne accepted a position at the University of Illinois. Charlotte and Arthur Crathorne had two further children, Anne Harrison Crathorne (1910-1979, born in Madison on 31 July 1909, and Arthur Robert Crathorne Jr (1912-1944), born in Illinois on 5 June 1911.

In 1909 Arthur Crathorne, together with his colleague Henry Lewis Rietz at the University of Illinois, published College Algebra. It proved very popular and ran to at least six editions. The review [15] explains:-
Its special claims on our notice are set forth in the Preface as: (i) The method of reviewing the algebra of the secondary school; (ii) the selection and omission of material; (iii) the explicit statement of assumptions upon which the proofs are based; (iv) the applications of algebraic methods to physical problems. The book seems to us to be a sensible production, and teachers will find some of the sets of examples very useful.
Charlotte's daughters report that their mother worked with her husband and Rietz on the production of this book but although the authors give acknowledgements to many in the work, she does not receive a mention.

At the age of 37 Charlotte Crathorne began to suffer from poor health. She died of breast cancer at the age of 40. The Champaign Daily Gazette from Champaign, Illinois reported [8]:-
Word has been received here of the death of Mrs Charlotte Crathorne, wife of Professor Arthur R Crathorne, of 1113 South Fourth Street, who passed away yesterday at the home of her parents, Mr and Mrs W S Pengra, at Broadhead, Wisconsin. Mrs Crathorne had been in falling health for some time and was recently taken to the home of her parents after spending months in St Luke's hospital in Chicago. ... Mrs Crathorne was a member of the Phi Beta Kappa sorority and was a patroness of the local chapter of Phi Kappa Sigma and past vice-president of the Association of Collegiate Alumnae. She was also a member of the Episcopal church.
Charlotte Crathorne was buried in Mount Vernon Cemetery, Juda, Green County, Wisconsin.

We note that Arthur Robert Crathorne remarried in 1917 to Katherine Alberta Layton (1878-1971) and spent the rest of his career at the University of Illinois becoming a full professor in 1935. In addition to writing a number of popular textbooks, Crathorne was a Ph.D. advisor to eight students at the University of Illinois.


References (show)

  1. 20 Years Ago Today, Wisconsin State Journal from Madison (Saturday 21 June 1924). 20 Years Ago Today, Wisconsin State Journal from Madison (Saturday 21 June 1924).
  2. F E Allen, Linnaeus Wayland Dowling in Memoriam, Bulletin of the American Mathematical Society 35 (1) (1929), 123.
  3. Charlotte Elvira Pengra, mathgenealogy.org (2025).
    https://www.mathgenealogy.org/id.php?id=7941
  4. Charlotte Elvira Pengra, The 1900 Badger, University of Wisconsin (2025).
  5. Charlotte Elvira Pengra Crathorne, findagrave.com (2025).
    https://www.findagrave.com/memorial/15542531/charlotte_elvira-crathorne
  6. Charlotte Elvira Pengra, History of Women Mathematicians, University of Wisconsin (2025).
    https://math.wisc.edu/history-of-women-mathematicians/
  7. Charlotte Elvira "Lottie" Pengra, ancestry.com (2025).
  8. Died at Home of her Parents: Mrs A R Crathorne of this City Passed Away at Broadhead, Wisconsin, The Champaign Daily Gazette (Thursday, 10 February 1916).
  9. J Green and J LaDuke, Florence Eliza Allen, in Supplementary Material for Pioneering Women in American Mathematics: The Pre-1940 PhD's. American Mathematical Society (American Mathematical Society's 2009).
  10. C E Pengra, On the conformal representation of plane curves, particularly for the cases p = 4, 5, and 6, Trans. Wisc. Acad. Sci. Arts Letters 14 (1904), 655-669.
  11. L Riddle, Charlotte Elvira Pengra (May 30, 1875 - February 7, 1916), Biographies of Women Mathematicians, Agnes Scott College (12 January 2022).
  12. University of Wisconsin, 1899 Calendar 29 (June 1899).
    https://search.library.wisc.edu/digital/ADSKPPXHMWLW4D8G/pages/AMMJ5EXYX4NNV68G?as=text&view=scroll
  13. D E Zitarelli, A History of Mathematics in the United States and Canada: Volume 1: 1492-1900 (American Mathematical Society, 2019).
  14. D E Zitarelli, The Hilbert American Colony (2025).
    https://davidzitarelli.wordpress.com/wp-content/uploads/2017/12/web11tr1900.pdf
  15. Anon, Review: College Algebra by H L Rietz and A R Crathorne, The Mathematical Gazette 5 (90) (1911), 399-400.

Additional Resources (show)

Other websites about Charlotte Pengra:

  1. Mathematical Genealogy Project
  2. zbMATH entry

Cross-references (show)


Written by J J O'Connor and E F Robertson
Last Update March 2025