Scientific and technical progress in our country depends largely on supplying im­ portant sections of the national economy with modern materials. This may be done by improving traditional materials, as well as by developing new ones that may be used under severe temperature, stress, and velocity conditions and that have com­ binations of certain physical and chemical properties. Refractory, superhard, corrosion-resistant, semiconductor, dielectric, and other materials are thus being created that will permit the development of new, highly effective tool materials, the implementation of technological processes in plasmas, and the solution of some materials-related aerospace and nuclear power problems. Refractory compounds play a vital role in the development of new materials and in the improvement of traditional materials. But information available on the properties of refractory compounds needed by scientists and engineers engaged in producing new materials for industry and technology has not yet been properly systematized. A first attempt in 1963 at such systematization (the first edition of this book) played some part in expanding the development and use of refractory compounds, but the information has now become seriously outdated, especially since in the last decade the study of refractory compounds in the USSR and abroad has grown very rapidly. In 1964 the handbook was, with certain additions, translated and published in the USA, but that publication was not readily available to the Soviet reader.