According to Wikipedia, Carolyn Eisele was an American mathematician and historian of mathematics known as an expert on the works of Charles Sanders Peirce. Education and career Eisele was born on June 13, 1902, in The Bronx, New York City. She studied at Hunter College High School and then Hunter College, graduating Phi Beta Kappa in 1923. She earned a master's degree in mathematics and education from Columbia University in 1925. At that time, Columbia did not offer Ph.D.s in mathematics to women, but Eisele continued her graduate studies at the University of Chicago and the University of Southern California before returning home to New York, without a doctorate, to care for her injured father. Her studies also included opera singing, with Jeanne Fourestier in Paris in 1931 and later with Los Angeles-based voice coach Morris Halpern, whom she married in 1943.