The Leverhulme Trust (UK) required Charles Oxnard to present a series of public lectures during his tenure of a Leverhulme Professorship at University College, London. The lectures had to be understandable not only to undergraduate and graduate students and colleagues, but also to the interested lay public. Furthermore, they were expected to meet and venture beyond present-day thought in the subject. This near-impossible task is reproduced in this unique volume. Each chapter shows what is rarely, if ever, done in scientific papers: how the problems truly arose; how the methods came about; the...