The purpose of this book is to provide the reader with a series of work- ed examples in X -ray spectrometry and X -ray diffractometry, in such a way that each example can be treated either as a posed question, i. e. one to which the reader must himself provide an answer, or as a guide to the method of treating a similar problem. The latter, of course, also pro- vides a check on the answer produced by the reader. Although much basic theory can be derived...