A detailed account of Lindsay's ancestry and family life in Massachusetts; studies at Brown University and Massachusetts Institute of Technology, and Ph.D. in physics in 1924. The autobiography describes the Lindsay's years at Yale University (1923-1930) and his return to Brown University in 1930 where he became chairman of the physics department and, later, dean (1948). Subjects discussed include his scientific and administrative work; association with National Bureau of Standards; position as editor of the Journal of the Acoustical Society from 1950; and conferences, travels, and professional society memberships. Lindsay also comments on other scientists and his collaborations with them and students; and on teaching after retirement (1968-1971). The supplement covers travels in Europe in 1970s and 1980s and accounts of Lindsay's professional life interspersed with personal memories. He discusses the Sigma XI Lectures given in 1971 and 1975; several relationships existing in correspondence only and their value to Lindsay; his reappointment in 1978 as editor-in-chief for the Acoustical Society; the American Institute of Physics 50th anniversary publications; and writing activities, lectures, and seminars in early 1980s. The autobiography includes an appendix, which was edited and typewritten from a handwritten manuscript found after his death in 1985 by his daughter, Evelyn Lindsay Roberts. Topics covered in the appendix include his childhood, family relationships, college years at Brown, study and teaching at M.I.T., courtship and marriage, and the early years of his career at Yale.