This handbook was published in 1914 to accompany the Napier Tercentenary Exhibition. It describes exhibits of all types of calculating machines, as well as mathematical literature, logarithmic tables, and objects of historical connection with John Napier, the man who discovered logarithms. It includes an account of Napier's life and times and gives a short description of how to use Napier's bones as well as more detailed descriptions of such measuring devices as the abacus, slide rule, planimeters, harmonic analyzers, and differentiating machines. The material is illustrated with a large number of engravings, photographs, and diagrams. It is perhaps the best English language account of machines and techniques used for calculation before the first World War. The book is Volume III in the Charles Babbage Institute Reprint Series and was first published by G. Bell and Sons, Ltd., and the Royal Society of Edinburgh.