So encrusted with folklore has Edison's invention of the electric light become that we may be hard-pressed to recognize its significance. This account, unlike others, focuses on the invention rather than the inventor to remind us how extraordinary an achievement it was. Friedel and his colleagues draw chiefly on notes, calculations, and sketches from Edison's laboratory notebooks as well as other contemporary records to re-create the process of invention. Eminently readable and meticulously researched, this illustrated volume is a scholarly work of high order. It belongs in every research collection and in most general collections as well.