British wiring parties in rain - Glass negative photogrpah. Public domain.

Photograph shows British soldiers taking unbarbed concertina wire to the forward area, near Hamel, September 1916 during the Battle of the Somme in World War I. (Source: Flickr Commons project, 2015 and Imperial War Museums website: http://www.iwm.org.uk/collections/item/object/205072805)
Title from data provided by the Bain News Service on the negative. Date from similar photograph on the Imperial War Museums website.
Photograph by Ernest Brooks (b. 1878).
Forms part of: George Grantham Bain Collection (Library of Congress).
General information about the George Grantham Bain Collection is available at http://hdl.loc.gov/loc.pnp/pp.ggbain