Ingenium is medieval English vernacular for "an ingenious contrivance." In this fascinating book, physicist Mark Denny considers five such contrivances—the bow and arrow, the waterwheel, the counterpoise siege engine (including the trebuchet), the pendulum clock anchor escapement, and the centrifugal governor—and demonstrates how they literally changed the world. Interweaving an entertaining narrative with diagrams, equations, and drawings, Denny shares the history of each device, explains the physics behind it, and describes how it was used, how it evolved, and why it is significant in today's world.

Consider the bow and arrow, which transformed warfare by allowing soldiers to attack their enemies at a safe distance. Or the waterwheel, which enabled Old World civilizations to grind grain, pump water, and power machines during a period of extreme labor shortages. Medieval warriors engaged in an early form of biological warfare by using the trebuchet to launch dead animals or plague-ridden corpses over enormous fortress walls. The pendulum clock forever enslaved modern humans to the clock by linking the accurate measure of time to the burdens of schedules, deadlines, promptness, and tardiness. And the centrifugal governor gave rise to an entire branch of modern engineering science: feedback control.

Reflecting on the inventors of these ancient machines and the times in which they lived, Denny concludes with thought-provoking observations about inventors, inventiveness, genius, and innovation. Whether you dream of making a better mousetrap or launching pumpkins into the stratosphere, Ingenium will tickle your fancy.

Mark Denny is a theoretical physicist who has worked in academia and industry. He is the author of numerous books, including Lights On! The Science of Power Generation, Making Sense of Weather and Climate: The Science behind the Forecasts, and Making the Most of the Anthropocene: Facing the Future.

Mark Denny's profile page

"A well-written, illustrated, and informative book that is readable to all but the mentally lazy."

"User friendly, filled with humor and practicality... not only 'technology wizes' but 'history buffs' and humanists too will enjoy and profit from this book."

European Legacy

"The subject matter is extremely well described."

School Science Review

"Denny has produced a book that is both educational and entertaining."

"This book will give the reader an appreciation of the effectiveness of ancient technology. It will also be a useful reference for engineering and physics instructors."

Science Books and Films

"[Ingenium] is a good place to learn how they actually worked and how far they could effectively serve the purposes of those who made and used them."

Technology and Culture