"Dr Fischer's book fills an important gap in the history of individual 20th century scientists. It is also of interest because it documents the immense activity of a very hard-working scientist who did not make any spectacular discoveries and yet contributed to many areas of physical science."Roy H GarstangEmeritus Professor, University of Colorado"Fischer does a good job of outlining the technical context of each of Hartree's contributions .. Extensive references to primary sources are provided, as is a complete listing of Hartree's publications."The International Meccanoman"This book presents not only the life and scientific achievements of Hartree but also shows some individuals who have recognized his contribution to their professional lives."Zentralblatt MATH