Instruct: Classify Amazon reviews into positive or negative sentiment
Query: An unexpectedly engrossing story

This book tells not one but three fascinating stories. The first is the personal story of Chester Carlson, from his impoverished early life, through financial success to his philanthropy in later life. Carlson was a man of great humility and generosity.The second is the fascinating engineering story in which a cumbersome process that barely worked in the laboratory is brought painfully to commercial fruition. After reading this book, you'll never take a copier for granted again.Finally, it is the business story of how the big players like Kodak and IBM failed to see the potential in the process, and how an unknown company (Haloid) was willing to take the necessary risks.I am in the commercial printing business and have raved about this book so much that I bought two copies to loan to customers and others in the industry. It's that good.