Lester R. Ford

Lester Randolph Ford (1886-1967), called Lester R. Ford Sr. to tell him apart from his mathematician son L. R. Ford Jr., was an American mathematician and a noted expositor. Born in Rich Hill, Missouri, he studied at the University of Missouri and at Harvard, lectured at the University of Edinburgh from 1914, and took his Harvard doctorate in 1917 with a thesis on rational approximations to an irrational complex number. He later taught at the Rice Institute and then headed the mathematics department at the Armour Institute of Technology, which became the Illinois Institute of Technology. His books include Automorphic Functions (1929) and Differential Equations (1933), and the geometric picture of the Farey series known as Ford circles comes from his 1938 article Fractions. He edited the American Mathematical Monthly from 1942 to 1946 and was president of the Mathematical Association of America in 1947 and 1948; the Lester R. Ford Award is named for him.