Chapter XII applications

After a review of the past three issues of the Applications chapter, the author realized that too little attention had been paid to the growing literature in countries other than the United States. In the current chapter, therefore, a more extensive review of the foreign literature has been made, and, in view of the increased length of the chapter, certain United States references have been omitted. Some of the latter are either not of major importance or are continuations of work already reported for which an opportunity for review will occur in subsequent years.