iv About the Authors During his career, Dr. Walter C. Brown was a leading authority in the fields of drafting and print reading. He served as a consultant to industry on design and drafting standards and procedures. He authored several books in the fields of drafting, print reading, and mathematics, and was a professor in the Division of Technology at Arizona State University, Tempe, Arizona. Dr. Ryan K. Brown is a retired faculty member of the Department of Technology at Illinois State University, Normal, Illinois, where, for 26 years, he taught various drafting and design courses in both mechanical and architec- tural applications. His teaching experiences also include four years as a faculty member at his alma mater, Eastern Kentucky University, and five years teaching drafting at the junior and senior high level. His work experiences cover a variety of short-term consulting positions with a wide range of drafting and graphics- based tasks, such as steel detailing, plant layouts, and architectural drawing and modeling. Throughout his career, he has conducted workshops for companies in the field of print reading and geometric dimensioning and tolerancing. As a service to secondary education in Illinois, he continues to serve as a test author for various drafting and design competitions. With respect to this text and accompanying materials, feel free to contact the author, Dr. Ryan K. Brown, at the following email address: rkbrown@ilstu.edu.