Nearly three years have passed since the publication of the original Russian edition, in which time there have appeared various papers on recent research on the transuranium elements, of which the most notable concern the production of element 105 at Dubna and Berkeley. There has also been much fresh information on elements 104 (kurchatovium) and 103 (lawrencium). Our knowledge of shell effects in the fission barrier has been extended. Hopes of finding relatively stable superheavy elements have stimulated searches for such elements in nature as well as rapid development in heavy­ ion acceleration. We may see some very considerable discoveries in the next few years. The new results vary in reliability, and so it is not surprising that some papers on the properties of the heaviest elements have given rise to vigorous debates, whose value lies in the way they ad­ vance the subject. We have not attempted to give an exhaustive survey of recent papers and have merely added brief sections to reflect what we con­ sider to be the most important points from these. So far, the United states and the USSR have made the most considerable contributions to the synthesis, study, and use of the transuranium elements, so it is especially welcome to us that this book, first published in our country, should now appear in the USA in an English translation.