Archivo: Various gas masks WWI

Description: Various types of gas masks used during the first world war.
Title: Various gas masks WWI
Credit: "The Literary Digest History of the World War", volume V, p. 55.
Author: Halsey, Francis Whiting,
Permission: This media file is in the public domain in the United States. This applies to U.S. works where the copyright has expired, often because its first publication occurred prior to January 1, 1923. See this page for further explanation. This image might not be in the public domain outside of the United States; this especially applies in the countries and areas that do not apply the rule of the shorter term for US works, such as Canada, Mainland China (not Hong Kong or Macao), Germany, Mexico, and Switzerland. The creator and year of publication are essential information and must be provided. See Wikipedia:Public domain and Wikipedia:Copyrights for more details. First published in the USA before 1923.
Usage Terms: Public domain
License: Public domain
Attribution Required?: No