On May 8, 1925, Donald Bradner and Oglesby Nicholas patented a process of producing smoke clouds from moving aircraft – This Day in Patent History

The smoke producing liquids are dropped from an aircraft, wherein the liquid reacts with one or more of the constituents of the air or atmosphere and generates a smoke screen as it falls.

Patented technology could be employed for laying screens of smoke from aeroplanes to protect the planes from antiaircraft attack or to protect land fortifications, troops, or ships from enemy fire.

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