Leopold Infeld was one of the nine eminent scientists who, together with Albert Einstein, signed Bertrand Russell's famous letter warning that in this nuclear age, only a ban on war itself could save this planet (July, 1955). Infeld was born in the Jewish ghetto of Cracow, Poland in 1898, and this autobiography contains a vivid description of this long-since-vanished world. He was assistant to and then a scientific collaborator with Albert Einstein at the Institute for Advanced Study, Princeton, NJ (1936-1938), and this collaboration continued for twelve years while Infeld was at the University of Toronto. In 1938 he wrote a book together with Albert Einstein that became a number one bestseller, The Evolution of Physics. Infeld was lecturer and then Professor of Applied Mathematics at the University of Toronto from 1938--1950. From 1945-1950 he gave many lectures all over Canada on the elementary physics of the atom bomb, warning that Russia would soon have the bomb and urging that the short period