Although each of the pieces included in this collection has been cited as an outstanding contribution to the literature on the subject, they are not available in most libraries. Each of them is a classic on the theory of double-entry bookkeeping. Of the nine articles reprinted in this volume originally published in 1984, those by Ladelle, Hotelling and Anton are recognized as being the classic articles on the depreciation of a single 'machine'. Each of these articles was published in a journal that is often not accessible and reprinted here has brought them together in one place. For many years accountants have dealt with depreciation and capital maintenance as a static problem. This volume recognizes its dynamic aspects.