7 The 100 Most Influential Inventors of All Time 7

large-scale automatic calculator and a precursor of electronic

computers. She remained at Harvard as a civilian research

fellow while maintaining her naval career as a reservist. After

a moth infiltrated the circuits of Mark I, she coined the

term bug to refer to unexplained computer failures.

In 1949 Hopper joined the Eckert-Mauchly Computer

Corp., where she designed an improved compiler, which

translated a programmer’s instructions into computer

codes. She remained with the firm when it was taken over

by Remington Rand (1951) and by Sperry Rand Corp.

(1955). In 1957 her division developed Flow-Matic, the first

English-language data-processing compiler. She retired

from the navy with the rank of commander in 1966, but

she was recalled to active duty the following year to help

standardize the navy’s computer languages. At the age of

79, she was the oldest officer on active U.S. naval duty

when she retired again in 1986. She was elected a fellow of

the Institute of Electrical and Electronic Engineers (1962),

was named the first computer science Man of the Year by

the Data Processing Management Association (1969), and

was awarded the National Medal of Technology (1991).

Frank Whittle

(b. June 1, 1907, Coventry, Warwickshire, Eng.—d. August 8, 1996,

Columbia, Md., U.S.)

F

rank Whittle was an English aviation engineer and

pilot who invented the jet engine.

The son of a mechanic, Whittle entered the Royal Air

Force (RAF) as a boy apprentice and soon qualified as a pilot

at the RAF College in Cranwell. He was posted to a fighter

squadron in 1928 and served as a test pilot in 1931–32. He then

pursued further studies at the RAF engineering school and

at the University of Cambridge (1934–37). Early in his career

Whittle recognized the potential demand for an aircraft that