PHOTO: United States Army – Fort Leonard Wood Chemical Warfare Museum

During the early years after World War I, the United States Army's Chemical Warfare Service (CWS) employed exhibits to advertise its progress in lachrymatory – that is, tear-producing – agents at shows such as New York's Electrical and Industrial Exposition and Alabama's 1924 State Fair, shown here. The McBride Gas Gun, visible in the center of the picture, was one of several riot-control products invented by Captain Lewis McBride, a CWS officer. The gas-expelling armament was adopted by police departments to combat the plague of getaway-car-driving "motor bandits" of the 1920s and 1930s.