H. Harold Hartzler was born in Fort Wayne, Indiana, on April 7, 1908, and died in Goshen, Indiana, on December 9, 1993. An undergraduate at Juniata College in Huntington, Pennsylvania, he completed his doctorate in physics at Rutgers in 1934 working on the ultraviolet transmission of thin metallic films under the supervision of Robert d'E. Atkinson. He taught mathematics and physics at Goshen College (Indiana) from 1937 to 1958, and was professor of physics and astronomy at Mankato State University (Minnesota) from 1958 to 1976. During a sabbatical leave in 1948-49, he worked as a fellow in the astronomy department at the University of Arizona, which then consisted of two professors plus himself. Hartzler played a particularly prominent role in the American Scientific Affiliation, an organization whose members take both science and the Bible seriously; he served as its secretary-treasurer, president, and (for eleven years) as its first executive secretary. He was also one of my most influential undergraduate teachers.