 In the late 1930s, he travelled abroad widely to explore the use and advances of broadcast technology.In 1938, the Empire Service was reorganised into the Overseas Service and he became its first Director, overseeing foreign language broadcasts in the wake of the 1938 Munich Crisis.In 1941, the Overseas and European Services were separated, with Clark remaining as Controller of the Overseas Service; between 1944 and 1945 he served as Temporary Controller of European Services.