Englishman Charles Babbage (1791–1871), an eccentric, ingenious mathematician, decided that existing tables of computations included far too many errors: the day's textbooks came with errata sheets ...

As you might expect from its name, the "Difference Engine" is a strangely difficult object to describe. You might start by imagining the side of a large crib with uprights ringed by small metal wheels ...

For many of us, the computer is the symbol of our hypermodernity, the image of how vastly we differ--culturally, economically, socially and politically--from past generations. And many of us think of ...