William Oughtred: A Great Seventeenth-Century Teacher of Mathematics is a comprehensive exploration of the life, work, and enduring influence of William Oughtred, one of the most significant mathematicians and educators of the seventeenth century. Authored by Florian Cajori, this detailed biography delves into Oughtred's remarkable contributions to mathematics, particularly his innovations in mathematical notation and his invention of the slide rule, a tool that revolutionized calculation for centuries. The book traces Oughtred's early life, his education at Eton and King's College, Cambridge, and his long tenure as a parish priest, during which he mentored a generation of mathematicians and scientists who would go on to shape the scientific revolution. Cajori provides an in-depth analysis of Oughtred's major works, including the influential Clavis Mathematicae, which made advanced mathematical concepts accessible to a wider audience and introduced symbols and methods still in use today. The narrative highlights Oughtred's unique teaching methods, his correspondence with leading thinkers of his time, and his role in the intellectual ferment of seventeenth-century England. The book also examines the controversies and rivalries that marked Oughtred's career, such as his disputes over the invention of the slide rule and his interactions with contemporaries like John Wallis and Seth Ward. Richly illustrated with historical documents, letters, and diagrams, William Oughtred: A Great Seventeenth-Century Teacher of Mathematics not only illuminates the achievements of a pioneering mathematician but also paints a vivid portrait of the era's scientific and educational landscape. It is an essential resource for anyone interested in the history of mathematics, the development of mathematical tools and notation, and the lives of the individuals who shaped the modern scientific world.