American soldiers used flamethrowers in both the Pacific and European theaters. They were especially effective against enemy soldiers dug into bunkers that were difficult to penetrate by rifle or machine-gun fire. The Marine shown here, fighting in the Solomon Islands in 1943, carried on his back canisters of jellied gasoline and compressed air that were combined and projected through the gunlike machine. Photo: National Archives, Flamethrower: National Museum of American History, Smithsonian Institution, Behring Center.