This book is indeed a treatise on physical locks, with a focus on the history, construction, and evolution of the mechanisms involved up to 1853. Lock-making has occupied a large amount of ingenuity, and lock-patents have been obtained in considerable number, though not always, we are satisfied, with a commensurate return for the expense incurred,—but lock-philosophy (if so it may be designated) has not been largely attended to. The book also aims to cover that gap, by evaluating existing types of locking mechanisms and the thoughts that go behind devising such inventions.
