Preface to the fifth edition

The first draft of this book was started in 1989, the year the Berlin wall came down and the first edition appeared in 1991 making our ‘child’ legal by this, the fifth, edition.

As an eighteenth birthday present this edition includes, as well as the usual extensive rewrite and update of the text, a substantial improvement in the quality of the illustrations, which are now in colour and integrated into the text. This will mean less space for making your own notes in the blank pages but we suspect you will be willing to make the trade-off.

In keeping with previous practice new contributors have been included in order to ensure the material is as up to date as possible and we have tried to avoid overemphasizing our current areas of sub-specialization. As before, this book is the sum of its previous incarnations helped by feedback from readers from all parts of the world and the input of contributors. As always, responsibility for any errors or omissions lies with us.