The List Maker

January 18, 1779 - Peter Mark Roget was born in London on this day. He is remembered for publishing the Roget's Thesaurus of English Words and Phrases, but that is just one of his many contributions to history.

Roget studied medicine and published pioneering papers on tuberculosis, and on the use of  nitrous oxide as an anesthetic. Some historians say that his research into "laughing gas" was more recreational than scientific.

In 1814 he invented the slide rule to calculate the roots and powers of numbers, which made life easier on countless students of mathematics. In 1824 he presented an important paper with the long-winded title, Explanation of an optical deception in the appearance of the spokes of a wheel when seen through vertical apertures. This proved to be an influential study on the persistence-of-vision phenomenon, which would help lead the way toward the invention of motion pictures.

Roget's personal life was plagued with sadness. His father died young, as would Roget's wife. He battled depression and many believe that his obsession with keeping lists was a coping mechanism.

After retiring from science in 1840, he devoted most of his time to his massive collection of synonyms. When it was first published in 1852, Roget's thesaurus contained 15,000 words. Though it is continually updated with new editions, his book has never been out of print and remains one of the most important publications of all time.