The Spectrum Series of the Mathematical Association of America

was so named to reflect its purpose: to publish a broad range of books

including biographies, accessible expositions of old or new rnathe-

matical ideas, reprints and revisions of excellent out-of-print books,

popular works, and other monographs of high interest that will

appeal to a broad range of readers, including students and teachers

of mathematics, mathematical amateurs, and researchers.