The Science and Practice of Welding was first published in 1940 and immediately established itself as the best available introductory text on the theory of welding processes and their application. Each new updating has increased the size of the book. This eighth edition has therefore been split into two volumes along the natural division separating theory and application. Volume I introduces the relevant principles of physics, chemistry, metallurgy, electricity and weld testing. The section on electrical principles includes a simple explanation of the silicon diode and its operation, together with the operation of the thyristor and its use to obtain stepless; welding current control in the latest type of units. The testing of welds, both non-destructive (NDT) and destructive, has been brought up-to-date with new sections on X-ray and gamma-ray testing and the latest British Standards designations are used throughout. Volume 2, entitled The Practice of Welding, discusses in detail all the major welding processes used at the present time. Great changes are occurring in the practice of welding. The sections on MIG and TIG methods have been expanded in the light of these developments and the volume has been brought completely up-to-date, with many new illustrations and drawings. Both volumes contain numerous questions of the type set in craftsman and technician grades of the City and Guilds of London examinations.