THIS study of a relatively small industry illustrates a surprising number of the more important features and problems of modern mass production industry in which competition, efficiency and technical progress are linked on a world-wide scale. Economies of scale in the development of very high-speed and highly specialized production-processes have provided the incentive to concentrate production under the central control of a very few large enterprises; while economies in delivery costs have provided the incentive for geographically dispersed plants, of limited size, situated close to the customers. Thus, in Britain the largest producer-the Metal Box Company-has about two dozen plants 'strategically placed throughout the United Kingdom';' in Germany the leading enterprise, Schmalbach- Lubeca, has i i plants spread all over the country. The maximum delivery distance for cans is usually under IOO miles. There is a small amount of foreign trade of a specialized kind, such as aerosols, heavily decorated boxes and exports to under-developed countries. This study will consider: how the dominance of a few American concerns evolved; the role played by certain technological developments; the effects of competition by firms from other countries and other industries, the role of American and European antitrust laws, and the development of some remarkable international differences in productivity.