At the time of its establishment in 1966, by the International Council of Scientific Unions (ICSU), the Committee on Data for Science and Technol­ ogy (CODATA) was given the basic mission of promoting and encouraging, on a worldwide basis, the production and distribution of compendia and of collections of critically selected numerical data on substances other forms of interest and importance to science and technology. To accomplish this aim, the following tasks were assigned to CODATA: (1) To ascertain, on a worldwide basis, what work on compilation of numerical data is being carried on in each country and under each union, and from this information, to prepare and distribute a Directory or Com­ pendium of the Data-Compiling Projects and Related Publications of the World; (2) To achieve coordination of existing programs and to recommend new programs; (3) To encourage, from all appropriate sources, financial support for work on compilation; (4) To encourage the use of internationally approved symbols, units, constants, terminology, and nomenclature; (5) To encourage and coordinate research on new methods for preparing and disseminating data for science and technology. In its first two years of operation, 1966 to 1968, in Washington, D. c. , U. S. A. , CODATA fortunately had as its Director Dr. GUY WADDINGTON, who was also Director of the Office of Critical Tables of the National Research Council (NRC), U. S. A. Dr.