In 1869 H.J. Mettenheimer wrote the Auditor's Guide Being a Complete Exposition of Bookkeeper's Frauds - the first book about auditing from the earliest period of American accountancy. The sole remaining copy was found to have been destroyed, leaving only a barely readable microfilmed photocopy. This book, first published in 1988, presents a restored Auditor's Guide, finally available to historians of the early days of professional accountancy, together with the authors' analysis of this important text.