The authors gratefully acknowledge the help of Klaas Compaan, who was our advisor during the writing of this book. He guarded us against a number of errors and unclarities and also allowed us to publish the data for some of the new optical systems he has designed.
We received further support from Richard Berry, our editor. He invested a great deal of time in editing the text into a consistent whole, ready for the press.
We also gratefully acknowledge the highly skilled assistance of Diane Lucas, who patiently edited the original Apple programs. She translated these programs into very convenient IBM programs that are easy to use.
The authors are indebted to the publisher, Willmann-Bell, Inc., for the excellent care bestowed on the design and production of the book.
We want also to record our gratitude to Ans Colaris, who typed and patiently retyped our manuscript.
Finally, we wish to thank our wives, Elly and Ans, and our children, Maurice,
Marie-Pauline, and Aad, for accepting the restricted social life that accompanied the preparation of this book during a period of more than a year.