Having written thorough lives of individual visionaries including Einstein and Franklin, Walter Isaacson was already at work on the group portrait that would become The Innovators (Simon & Schuster, $35) when Steve Jobs interrupted him to write Jobs’s authorized biography. After completing that bestseller, Isaacson returned to his abandoned manuscript, which is now this polished and masterful narrative of how diverse wizards of technology worked at myriad intersections of art and science to create both computers and the internet. Many will be astonished to learn that the earliest insight into this technology was achieved by Ada Lovelace (1815-1852), daughter of Lord Byron, who is credited with being the first computer programmer and with developing the first algorithm. Lovelace worked with Charles Babbage on his Analytical Engine, a distant prototype of many later devices theorized and assembled by figures including Alan Turing, John von Neumann, Vannevar Bush, Grace Hopper, and many more. Isaacson documents in fascinating detail these hard-working geniuses’ decades of trials and errors.