During the 2nd World War, assayed aerial smokescreen by the US Army. The plane cast titanium tetrachloride from above, yellowish corrosive liquid. In moist air, titanium tetrachloride is readily hydrolyzed, thus generates a dense white smoke consisting of hydrochloric acid droplets and particles of titanium oxychloride. This large 'curtain' was tested as a visual barrier, to protect the bombers from anti-aircraft fire.