This volume contains six important articles in materials science and materials engineering, based upon inaugural lectures given by professors at Imperial College, London. Each author deals with an area of work in which he has been involved over a period of years, and gives a personal account, partly historical, of the main features and importance of his subject. The topics covered include: the strength and deformation of metals, the brittle behaviour of ceramics, electrical materials, biomaterials, friction and lubrication, and modern engineering adhesives.