I've been searching for this kind of book for years. I read almost all of it in one sitting, enthralled by the unfolding story of the invention of gaslight and electric light, and marveling at the wonderful details about how Europeans and Americans responded to these totally revolutionary inventions, and how both helped to transform the world in which we live. I hadn't realized gaslight was invented largely to light factories, that it was an immediate product of the industrial revolution in England on the most basic level, or that its "heyday" (1850-1870) in the cities of the world was so short. The details about arc lamps and attempts to illuminate cities from high towers also surprised me. But the book also contains a wealth of information about the use of light earlier --- how well to do people only used candles up to 1800, for example, and how oil lamps developed afterwards,etc. The descriptions of early shopping streets starting in the 1700's and how they used light, mirrors and eventually (by 1850)plate glass to display their wares were enthralling. ---- The in depth discussions of the psychology of light also fascinated me --- how people respond to flickering flames, how an oil lamp became the focal point of a family gathering much as the primitive hearth had once been the focal point; how people clung to candles and oil lamps in drawing rooms even when they had gaslight in other parts of the house, etc. ---- But I cannot do justice to the richness of this book by listing these things here. This is a brilliant study of people and light on many different levels, and beautifully written and engaging from start to finish. Highly recommended. (Historical novelists will love this book; it will tell them all kinds of things about the world of the last two centuries; it's full of priceless details.)