This scientific biography of Douglas R Hartree not only describes important events in his life but also outlines his contributions to a number of fields. He is best known for his "self-consistent field" theory for atoms, a theory he later used for the much more difficult problem of predicting the behavior of a magnetron. When Fock pre-empted his work on exchange, he began research into radio-wave propagation. Hartree was very interested in the process of computation. When he learned of a differential analyzer for solving differential equations, he first built a model using Meccano, a toy for...