The photographs that define our times. There are no fashion photographs, no art photographs and no formal photographs. There are no funny animal pictures and no human-interest pictures. Instead, the emphasis is on the historic pictures that constitute a visual map of our times - and on a few lesser-known pictures that shed a revealing light on the ways and days of life in the twentieth century. Rather than trying to find a picture of the century, we have concentrated on pictures that are great on their own terms, those that endure in our mind as icons of the times.