Dr. Wyckliffe Rose, director of the International Health Board of the Rockefeller Foundation from 1913 to 1923, defined the objective of international health as an attempt to bridge the gap between available medical knowledge and the application of that knowledge in public health practice throughout the world. This concept was much broader than that at the beginning of the century, when the Pan American Sanitary Bureau (1902) and the International Office of Public Hygiene (1907) were created to permit countries to collaborate in the prevention of the spread of communicable disease epidemics from country to country. The Rockefeller Foundation soon learned that available knowledge is never complete and expanded the concept of international health to include continuing research on scientific and administrative phases of health activities. It also found that imported activity within a country is relatively futile unless provision is made for the development of permanent health services staffed