We used to go in the small hours of the morning to the worst tenements... and the sights I saw there gripped my heart until I felt that I must tell of them, or burst, or turn anarchist, or something... I wrote, but it seemed to make no impression. One morning, scanning my newspaper at the breakfast table, I put it down with an outcry that startled my wife, sitting opposite. There it was, the thing I had been looking for all these years. A four-line dispatch from somewhere in Germany, if I remember right, had it all. A way had been discovered, it ran, to take pictures by flashlight. The darkest corner might be photographed that way.