A photograph of a sentry outside Wellington Barracks, London, dressed in a full chemical protection suit and a gas mask, taken by Sayers for the Daily Herald newspaper on 10 February, 1938. The sentry was taking part in a demonstration on air raid precautions. A piece of specially treated paper is attached to his bayonet. This acts as a detector which changes colour when gas is present, enabling the sentry to raise the alarm. The photograph is from the Daily Herald Archive, a collection of over three million photographs. The archive holds work of international, national and local importance by both staff and agency photographers.
© NMeM / Daily Herald Archive / Science & Society Picture Library