Acknowledgements

The publication of this volume was made possible only because of the

dedication of several people. If we omit anyone, it reflects only on our memory and

not on our appreciation of their efforts.

It is a special pleasure for us to acknowledge, among others, Professor Vladimir

Wataghin, who immediately accepted the hard job of finding the copies of

Wataghin's papers, several of which dated from more than 70 years ago. He and

his wife made a very thorough list of all papers, which formed the main document

of our collection.

Our thanks go to :

Maria Fabiana Bezerra Muller, Benedita Secundina Gonçalves Imamura,

Maria Aparecida Gonçalves, Rosana Aparecida Martins, for searching and

finding many of the papers in libraries in Brazil and abroad;

Valdineia Mara Viana, Marcos Abreu Nery, Wagner Luís da Silva, Marcos

de Freitas Vassao Junior, for their patient and accurate job of scanning old

papers, not always in good condition;

Professor Enrico Predazzi, for allowing us the use of his paper in the

Introduction of this volume;

Professor Carlos Henrique de Brito Cruz, Head of the "Gleb Wataghin

Physical Institute" of Unicamp, and his staff, for their constant support,

without which this job would have been much more difficult.

The Editors