Henry Ernest Dudeney (1857-1930) was an English author and mathematician who specialised in logic puzzles and mathematical games. He is known as one of the country's foremost creators of puzzles. Although Dudeney spent his career in the Civil Service, he continued to devise various problems and puzzles. His first puzzle contributions were submissions to newspapers and magazines, often under the pseudonym of "Sphinx". Much of this earlier work was a collaboration with American puzzlist Sam Loyd; in 1890, they published a series of articles in the English penny weekly Tit-Bits. Dudeney later contributed puzzles under his real name to publications such as The Weekly Dispatch, The Queen, Blighty, and Cassell's Magazine. For twenty years, he had a successful column, "Perplexities", in the magazine The Strand, edited by the former editor of Tit-Bits, George Newnes. Some of Dudeney's most famous innovations were his 1903 success at solving the Haberdasher's Puzzle and publishing the first known crossnumber puzzle, in 1926. In addition, he has been credited with inventing verbal arithmetic and discovering new applications of digital roots.