This book in its earlier editions was a joint product of Dick McKenzie and myself. We’ve had a completely friendlydivorce and so this book is his product with McKenzie listed as a contributor. He was a major contributor. Indeed many of the chapters which were carried over from the earlier edition were actually written by him rather than by myself. In fact, he will continue to draw substantial royalties on this edition, and somewhat smaller, but still substantial ones on succeeding revisions. He emphatically deserves the thanks of the now sole author and, I hope, of the readres for his very substantial contribution to the whole project.