This book records the life and times of Arthur Holmes who for several decades of his life strove to determine the age of Earth. Previous estimates had ranged from 60,000 years to 3 million years.Holmes would not accept these estimates and was rideculed and ignored by his coworkers but in the end he was vindicated whan radioactivity dating gave the age of Earth at 4.5 billion years. Along the way Holmes managed to transfer geology from an art to a science and become one of the U.K.s foremost scientists. A very well written and at times amusing story. A first class book.