Erastus L. De Forest

Erastus Lyman De Forest (1834 to 1888) was an American mathematician and statistician from Watertown, Connecticut. He studied mathematics at Yale, took his B.A. in 1854 and a Ph.B. in 1856, and was a fellow student of J. Willard Gibbs. After several years of travel and of teaching in California and Australia he returned to Connecticut in 1865 and devoted himself to mathematics, beginning with papers on interpolation. Asked by his uncle, the president of the Knickerbocker Life Insurance Company, to examine the company's liabilities, he published more than twenty papers between 1870 and 1885 on improving mortality tables, introducing formal criteria for smoothness and developing the use of least squares. Pearson later acknowledged his priority in deriving the chi square distribution, and he is noted as an early user of Monte Carlo methods. Shortly before his death he founded the Erastus L. De Forest Professorship of Mathematics at Yale.