Frank Wigglesworth Clarke (March 19, 1847 – May 23, 1931) of Boston, Massachusetts, and Washington, D.C. was an American scientist and chemist.

The USGS's Atomic Weights series became standard references for the chemistry and geochemistry professions and academic fields.

His Data on Geochemistry became a means of collecting peer professional efforts for common use across five successive editions.

[3] Beginning with his Constitution of silicates (1895), Clarke advanced a methodology of geochemical analysis which described a mineral's composition through fact coordination.

After Frank left for collegiate studies, Henry Clarke moved to Watertown where he resided until his death in 1907.

He then served as a Chemistry instructor under hydrocarbon scientist and fellow Lawrence School graduate, James Mason Crafts at the young Cornell University.

His short sojourn in Ithaca, New York prompted extensive surveys of local geologic forms, resumed when he taught at the University of Cincinnati.

[2]: 141 Clarke retired from the public service on January 1, 1925, having served as the Chief Chemist of the U.S. Geological Survey since 1883.

At the centennial of John Dalton's atomic theory held at Manchester, England in 1903, Clarke delivered the Wilde Lecture.

His forty-two year career included parallel service with the United States National Museum as 'honorary curator' of minerals.

In 1902, the need for commonality between active American and German scientific committees prompted the formation of the International Commission on Atomic Weights, with Frank Clarke as its chairman.

As chairman, Clarke guided the international committee in successive revisions of the Periodic Table of Elements which continued until interrupted by the First World War in 1918.

He would time his Cosmos Club library visits to coincide with the librarians' opening of the periodical mail and was keen on being the first to know, rather than the one to receive, the news.

Clarke's humorous use of language was compared to Lewis Carroll and the talent was renowned at Washington D.C.'s Cosmos Club.

While attending a friend's Thanksgiving dinner, Clarke noticed the host struggling with that metric of American male performance, the carving of the turkey.

Clarke "suggested that it might profit the carver to visit the National Museum, for a certain door therein bears on it the sign 'Division of Birds'.

Toward the end of his life, Clarke was described as "about five feet five inches in height, one hundred and ten pounds in weight, with pale blue eyes, little hair and most of that under his ears, chewing his finger nails and apparently absorbed in thought, though really most alert."

His praise he reserved for the individual's absence and many were advanced in his profession by Clarke's recommendation out of the earshot of the candidate.