Chad Table of Contents
The authors wish to thank individuals and private institutions who gave their time, research materials, and expertise to the production of this book. The authors are also grateful to members of the Federal Research Division staff who contributed directly to the preparation of the manuscript. These people include Richard F. Nyrop, who reviewed all drafts and served as liaison with the sponsoring agency; Martha E. Hopkins, who managed editing and production; Barbara Edgerton and Izella Watson, who provided wordprocessing support; and Helen C. Metz, who reviewed the text's French terminology.
Marilyn L. Majeska, Sharon Costello, Richard Kollodge, Lea Knott, and Michael Pleasants edited the manuscript; prepublication editorial review was performed by Beverly Wolpert; Shirley Kessell compiled the index. Diann J. Johnson of the Library of Congress Composing Unit prepared the camara-ready copy, under the supervision of Peggy Pixley.
Inestimable graphics support was provided by David P. Cabitto, assisted by Sandra K. Cotugno and Kimberly A. Lord; Ms. Lord also designed the cover artwork and the illustrations on the title page of each chapter. In addition, thanks are owed to Carolina E. Forrester, who reviewed the map drafts, and Harriett R. Blood, who prepared the topography and drainage map.
Finally, the authors acknowledge the generosity of the many individuals and public and private agencies who allowed their photographs to be used in this study. They are indebted especially to those who contributed original work not previously published.
Data as of December 1988