Today's Google doodle honors Hertha Marks Ayrton, a British engineer, mathematician, physicist and inventor in the late 19th and early 20th century. Aryton registered 26 patents: five on mathematical dividers, 13 on arc lamps and electrodes, the rest on the propulsion of air. Ayrton's interest in vortices in water and air inspired the Ayrton fan, or flapper, used in the trenches in the First World War to dispel poison gas. Ayrton fought for its acceptance and organized its production, over 100,000 being used on the Western Front.