Logarithms – this mathematical staple is celebrating its 400^{th} birthday this year. But how much do you know about the development of logarithms or the man behind them? Edinburgh born John Napier, the inventor of logarithms, is in danger of fading into the shadows of the scientific landscape. In the new book *John Napier: Life, Logarithms, and Legacy*, Julian Havil does a marvelous job of bringing Napier back into the spotlight.

Havil’s book is a self-proclaimed “scientific biography” – biography because it describes the life of Napier and scientific because it describes his work. Though the book focuses more on Napier’s scientific innovations, the first two chapters are dedicated to his life and his analysis of the Revelation. Not much is known about Napier’s life due to the fact that little about it was recorded and many of those records were lost. Despite this, Havil is able provide a basic sketch of Napier’s life, using historical facts to add perspective to the narrative. Though Napier is best known today for his development of logarithms, in his own time he was equally renowned for his scrutiny of the Revelation (the final Book of the New Testament). Napier’s work on the Revelation was immediately and widely embraced. Now a relic of history, Havil notes of Napier’s work on the Revelation:

Gone, but not entirely forgotten, it remains the epitome of its type providing the historian and theological scholar with important material on which to reflect.

The majority of the book focuses on Napier’s mathematical contributions, especially his development of logarithms. It is interesting to note that the logarithms Napier originally conceived are not the logarithms we know today. Havil presents Napier’s logarithms with enough detail to satisfy a mathematician without getting too bogged down in the details. Napier’s logarithms are not presented in a vacuum – Havil describes the motivating problems that drove Napier to develop logarithms, as well as how they were developed. In addition to logarithms, Napier’s Rods (or Bones) and his Promptuary are also presented.

The book ends with a survey of how Napier’s findings have influenced his successors. The most notable and famous of these is, of course, the development of the slide rule. However, Napier’s Rods and his Promptuary served as the inspiration for some analog computing devises. Napier also had a fruitful (if brief) collaboration with Henry Briggs, leading to the Briggsian logarithms and eventually the natural logarithms as they are known today.

If you’ve ever wanted to learn more about logarithms or the man who developed them, Havil’s book *J**ohn Napier: Life, Logarithms, and Legacy* is a great read. As Havil so aptly puts it, “John Napier deserves better than obscurity.”