The history of geology and how we learned about the age of the Earth is a fascinating subject, but Jackson, a geologist at Trinity College, Dublin, is unable to explain and pass along his enthusiasm. Aficionados might appreciate the tour through attempts to arrive at the planet's age from ancient myths, the Bible, the salinity of the oceans, temperature readings, fossils, geology, biology, radiology and cosmology. Each chapter ends with a "close but no cigar" statement of why a given theory was a good idea at the time. Numerous sections feel rushed—in particular the opening catalogue of creation myths—though when readers finally arrive at the sections on geology and fossils, Jackson injects more detail and, consequently, more interest. But while the preface states that this book is meant for a general as well as scientific audience, too many terms go undefined and too many names are dropped without immediate explanations of who the people were.