An extraordinary opportunity offered by the Du Pont Company gave Professor Hollander free access both to all detailed cost and much investment data related to rayon manufacture at a number of plants, covering a period of thirty years and to a wide range of informed personnel and officers. These data enabled Professor Hollander to make an unprecedented study of a large industrial firm for the purpose of measuring the contribution of various sources of improvement to increased efficiency. From the mass of information available, he has selected sound technical details and concepts, excluded...