December 1, 1847 - March 5, 1930
Christine Ladd was born in Windsor, Connecticut on December 1, 1847. After schooling at Wesleyan Academy in Massachusetts for two years, she entered Vassar College in 1866, but dropped out after one year because of financial difficulties. During the following year she did some teaching and continued her studies in trigonometry, biology, and languages on her own. Her interests in languages allowed her to translate Schiller's "Des Madchens Klage" into English, which was then published in the Hartford local newspaper. In the fall of 1868 Ladd returned to Vassar, graduating a year later.
It was only after she left college that Ladd began her serious study of mathematics. She published solutions to mathematical problems in the Educational Times of London and the American journal The Analyst, and even studied mathematics at Harvard with W. E. Byerly and James Mills Peirce. With the support of the English mathematician J.J. Sylvester, Ladd was allowed to attend graduate courses in mathematics at Johns Hopkins University despite the fact that the university was not open to women. Jacob describes how she managed to do that:
[T]he university first announced its fellowship program in 1876, and one of the first applications to arrive was one signed "C. Ladd." The credentials accompanying the application indicated such outstanding ability that a fellowship in mathematics was awarded to the applicant, site unseen, and was accepted. When it was discovered that the "C." stood for Christine, several embarrassed trustees argued she had used trickery to gain admission, and the board immediately moved to revoke the offer. They failed to reckon, however, with the irascible Professor James J. Sylvester, stellar member of the first faculty. In 1870 Sylvester had been named the world's greatest living mathematician by the Encyclopedia Britannica, and his presence at Hopkins was a real coup for the struggling university. He was indispensable and knew it, in an ideal position to insist on virtually anything he wanted; in this case, he had read Christine Ladd's articles in English mathematical journals, and he insisted upon receiving the obviously gifted young woman as his student. Miss Ladd was admitted as a full-time graduate student in the fall of 1878. Though she held a fellowship for three years, the trustees forbade that her name be printed in circulars with those of other fellows, for fear of setting a precedent. Dissension over her continued presence forced one of the original trustees to resign.
At Johns Hopkins Ladd developed her interest in symbolic logic through the lectures of Charles Sanders Peirce, writing a dissertation on "The Algebra of Logic" in which she solved a problem in Boolean algebra due to W.S. Jevons that was first articulated in the nineteenth century. (For an outline and explanation of Ladd’s contribution to the development of logical algebras in the nineteenth century, see the paper by Sara Uckelman.) Ladd also published several more articles in The Analyst. However, Johns Hopkins did not allow women to receive the Ph.D. degree, so Ladd left the school in 1882 without that official recognition. Her dissertation, however, appeared in the volume Studies in Logic by Members of the Johns Hopkins University, edited by Charles S. Pierce, Little, Brown & Co., 1883 (pages 17-71).
In 1882, Ladd married Fabian Franklin, a member of the Johns Hopkins mathematics department. They had two children, but only a daughter survived into adulthood. Ladd-Franklin continued working on symbolic logic as well as the field of physiological optics. This latter area carried her into research in the optics of color vision, an area in which she worked for thirty-seven years. In 1929 Ladd-Franklin published her collected works on color vision entitled Colour and Colour Theories.
In an obituary published in Science, R. S. Woodworth wrote:
The career of Dr. Christine Ladd-Franklin...was remarkable in several ways. It was remarkable for brilliancy of achievement. Her theory of color vision, whether or not it shall be the final word on the subject, has certainly done excellent service by holding together the most important facts, and by relating psychology, physiology and photochemistry, along with an evolutionary conception of the development of the color sense. This theory arose out of her study of the theories of Helmholtz and Hering during her work in Germany in 1891-92. She pointed out defects in each of these rival theories and showed how the merits of each could be combined into a single theory. Her work in symbolic logic, perhaps even more brilliant than that in color theory, dates from even further back, from her early days at the Johns Hopkins in 1878-82. Besides these major achievements there were several others of interest, especially her discovery with Konig in 1895 of the "normal night-blindness of the fovea," and her resuscitation of the "blue arcs" in 1926, and making something of theoretical interest out of this phenomenon.
Ladd-Franklin received many honors during her life. She was a lecturer on logic and psychology for five years at Johns Hopkins University (the only woman on the faculty) and for over fifteen years at Columbia University. She received an honorary LL.D. degree in 1887 from Vassar College and in 1926 was finally awarded a doctorate from Johns Hopkins, forty-four years after the completion of her dissertation. Throughout her life she championed the cause of graduate education and academic employment for women. For 17 years she helped to administer the Sarah Berliner fellowship to support recent Ph.D. women in their research. Christine Ladd-Franklin died of pneumonia in New York City on March 5, 1930.
Photo Credit: Smithsonian Institution Archives