Known for his early images of Scottish streets, Thomas Annan is the first photographer to document the living conditions of the poor. Here, the narrow, old “close” (back alley) features lines of laundry hung out to dry as well as ghostly human figures who stood or sat still just long enough to be captured by Annan’s long-exposure process.

This image is from “The Old Closes and Streets of Glasgow” series of photogravures. A photogravure involves etching the photographic image into a metal plate, applying ink to the etched grooves, then placing paper over the plate under enough pressure to absorb the ink from the grooves. The result is a print that captures the subtle tones of the original photographic image.