Fanning gas, George Grantham Bain Collection

Photo shows American soldiers being trained to use Ayrton or trench fan to clear poisonous gases during World War I, Camp Kearny, California. (Source: Flickr Commons project, 2016)
Title and date from data provided by the Bain News Service on the negative.
Caption from: Catalogue of Photographs and Stereopticon Slides ... Oct. 25, 1917 to Jan. 31, 1918 from the Committee on Public Information: "8641 The flapper fan in use. A gas wave coming over the trench, the men using the fan to clear the trench of gas. Training at Camp Kearney Cal."
Copyright by the Committee on Public Information (C.P.I.).
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