Source feministvoices.com
Christine Ladd was born on December 1, 1847 in Windsor, CT. Her father Eliphalet Ladd and her mother Augusta Niles both came from distinguished New England families. Ladd attended Wesleyan Academy for two years, graduating in 1865. She then entered Vassar College from which she graduated in 1869. Her main interests were mathematics and science. For the next nine years, she taught these subjects at secondary schools in New York, Massachusetts, and Pennsylvania and wrote several articles on mathematics. In 1878, she applied to become a student in advanced mathematics at Johns Hopkins University in Baltimore, MD. Women were at the time not permitted in graduate studies but her unusual mathematical capabilities resulted in an unofficial exception for her. She completed the requirements for a doctoral title in 1882 but officially received the degree only in 1926. Her thesis was titled “The algebra of logic” and was included in a volume of studies on logic by the famed philosopher C. S. Peirce in 1883 [1]. In the year 1882, she married Fabian Franklin, a mathematics professor at Johns Hopkins. She continued to write articles on mathematics and also logic where she proposed an anti-logic model opposite to the classical syllogism in an article titled “The algebra of logic.” It was considered a major achievement in its time. Her interest in color began when she investigated how points in space are dealt with by binocular vision.
In 1904, she finally was officially made a lecturer at Johns Hopkins University, but only for one course in each term: mathematics or logic in one term and vision/color in the other. However, it represented a big step in the recognition of women in American academia. She continued to have papers published in her fields of expertise. In 1929, a collection of her most important papers on vision and color was published with the title “Color and color theories” [2]. In 1910, Ladd-Franklin and her husband moved to the city of New York where she lectured at Columbia University. There she remained active as a strong supporter of women’s rights until the end of her life on March 5, 1930 [3].
48.1 Ladd-Franklin’s Color Vision Theory
Ladd-Franklin’s schematic representation of the three evolutionary stages in her color vision theory. In Stage III, the Yellow mechanism of Stage II is split into Green and Red [2]
She experimentally tested the Hering theory and in 1892 also found the fact that, in her disk mixture experiments, the achromatic appearance of a balanced red-green mixture to be different from that of the yellow–blue mixture.
In 1924, she authored the paper “The nature of the colour sensations” that was appended to Vol. II of the English translation of the third edition of Helmholtz’sTreatise on physiological optics, as well as in her 1929 book Colour and colour theories that represents a historically important review of her knowledge and ideas about color vision [2].