 Patterned ship camouflage was pioneered in Britain. Early in the First World War, the zoologist John Graham Kerr advised Winston Churchill to use disruptive camouflage to break up ships'outlines, and countershading to make them appear less solid, following the American artist Abbott Handerson Thayer's beliefs. Kerr was not an effective political campaigner, and his ideas were abandoned on Churchill's departure from the Admiralty, while his postwar legal action to claim credit for ship camouflage failed. His successor, the marine artist Norman Wilkinson, successfully promoted the idea that Kerr's camouflage sought invisibility rather than image disruption. Under Wilkinson, the Admiralty researched and issued a large number of "razzle-dazzle" designs, which became known simply as "dazzle", to counter the threat from submarines. Models were made and painted, often by women artists, and tested in a laboratory by viewing through a periscope. After trials, in October 1917 the Admiralty ordered all its merchant ships to be painted in dazzle patterns. The purpose of dazzle camouflage was not however motion dazzle but visual deception, as Wilkinson later explained:
