In the early summer of 1938, his boss asked him if he could build a calculator that would do arithmetic with complex numbers—the kind involving "imaginary" quantities based on the square root of—1. Those quantities had turned out to have some very real applications in the design of AT&T's new coast-to-coast system of long-distance lines, and Bell Labs' computer division—a small team of women armed with desk calculators—was being swamped by complex arithmetic.
