7 The 100 Most Influential Inventors of All Time 7

positive electric charge under the sheet attracts the

negatively charged ink particles, resulting in the transfer

of the image to the copy paper. Heat is then momentarily

applied to fuse the ink particles to the paper.

In 1938 Carlson and a research associate succeeded in

making the first xerographic copy. Carlson obtained the

first of many patents for the xerographic process in 1940

and for the next four years tried unsuccessfully to interest

someone in developing and marketing his invention. More

than 20 companies turned him down. Finally, in 1944, he

persuaded Battelle Memorial Institute, Columbus, Ohio,

a nonprofit industrial research organization, to undertake

developmental work. In 1947 a small firm in Rochester,

N.Y., the Haloid Company (later the Xerox Corporation),

obtained the commercial rights to xerography, and 11

years later Xerox introduced its first office copier. Carlson’s

royalty rights and stock in Xerox Corporation made him a

multimillionaire.

Grace Murray Hopper

(b. Dec. 9, 1906, New York, N.Y., U.S.—d. Jan. 1, 1992, Arlington, Va.)

G

race Murray Hopper (née Grace Brewster Murray)

an American mathematician and rear admiral in

the U.S. Navy, was a pioneer in developing computer tech-

nology, helping to devise UNIVAC I, the first commercial

electronic computer, and naval applications for COBOL

(common-business-oriented language).

After graduating from Vassar College (B.A., 1928),

Hooper attended Yale University (M.A., 1930; Ph.D., 1934).

She taught mathematics at Vassar College, Poughkeepsie,

N.Y., from 1931 to 1943 before joining the U.S. Naval

Reserve. She became a lieutenant and was assigned to the

Bureau of Ordnance’s Computation Project at Harvard

University (1944), where she worked on Mark I, the first