Full image caption
Air Raid Precautions rattle. During World War II, Air Raid Precautions wardens were employed to help members of the public during bombing raids. During training, wardens were instructed on how to respond to a gas attack. If poisonous gas were released over London, wardens were told to sound a hand rattle to alert people to stay indoors or put on their gas masks. Fortunately London never did experience any enemy gas attacks during the war.
© Museum of London