THOMAS BANCHOFF has been a professor of mathematics at Brown University in Providence, Rhode Island, since 1967. He has written two books and fifty articles on geometric topics, frequently incorporating interactive computer graphics techniques in the study of phenomena in the fourth and higher dimensions. He received his BA at the University of Notre Dame and his Ph.D. at the University of California, Berkeley. He has received the Lester Ford Award for exposition and the Joseph Priestley Award from Dickinson College. His computer graphics films have received international awards and have been featured at the International Congress of Mathematicians. On the hundredth anniversary of Flatland in 1984 he presented a lecture at the City of London School and organized a three-day conference at Brown University to celebrate the contributions of Edwin Abbott Abbott and the progress of visualization of higher dimensions over the past century. His latest book, Beyond the Third Dimension, has just been published. Am Address: Department of Mathematics, Brown University, Providence, RI 02912, USA