Charles Holland Duell (April 13, 1850 – January 29, 1920) was the Commissioner of the United States Patent Office from 1898 to 1901, and was later an associate judge of the Court of Appeals of the District of Columbia.

[2] Duell was nominated by President Theodore Roosevelt on December 16, 1904, to an Associate Justice seat on the Court of Appeals of the District of Columbia (now the United States Court of Appeals for the District of Columbia Circuit) vacated by Associate Justice Seth Shepard.

[1] Following his resignation from the federal bench, Duell resumed private practice in New York City from 1906 to 1913, and in 1915.

[6] In fact, Duell said in 1902: In my opinion, all previous advances in the various lines of invention will appear totally insignificant when compared with those which the present century will witness.

"[8]Another possible origin of this famous statement may actually be found in a report to Congress in 1843 by an earlier Patent Office Commissioner, Henry Ellsworth.