Several books have been published which describe the evolution and growth of the British iron and steel industry. Most of these provide accounts of the developments in manufacturing methods that have taken place. Some also discuss the products. Only limited reference is usually made, however, to the reasons why the changes were made or to the progressive evolution of the underlying scientific understanding that has transformed the modern approach to the design and operation of processes and to product development. There is no comprehensive coverage of the vast changes that have transformed the industry during the second half of the twentieth century.