Michael Vincent reported this story on Saturday, December 21, 2013 08:26:00

SIMON SANTOW: Today in 1913 the New York World published something that has gone on to obsess, even perplex newspaper readers ever since.



It even led to the birth of one of the biggest publishing houses in the world.



Here's a clue: it has nine letters, and starts with the letter 'C'.



Our North America correspondent and word sleuth Michael Vincent explains.



MICHAEL VINCENT: On December the 21st, 1913, Englishman Arthur Wynne created a diamond-shaped grid of numbered squares and clues for 32 words.



Readers loved it.



MERL REAGLE: Instantly yes, at the New York World it was, even though his bosses at the New York World thought it was pretty much a waste of time.



MICHAEL VINCENT: Merl Reagle is a crossword constructor whose work is published in 50 newspapers across the US.



He says Arthur Wynne struggled with his invention for eight years.



MERL REAGLE: He went to his bosses at the New York World and said 'we're getting tonnes of mail on this. This seems to be an extremely popular thing. We should copyright it or patent it or something', and his bosses at the World said 'no, it's a passing fancy - it'll go away in a couple of years'. So he never made a dime off the crossword puzzle.



MICHAEL VINCENT: But the woman who took over Wynne's job at the newspaper in 1921 did make money - a lot of it.



MERL REAGLE: Two guys came along who wanted to start a publishing business in 1924, came to her and said 'we want to publish the first crossword puzzle book'. There'd never been one before. She said 'OK, I'll get two friends of mine and we'll edit it for you.' And that book came out in 1924 and sold 400,000 copies in just a matter of months.



That was the very first book that Simon and Schuster ever published, and it just catapulted them into the publishing world.



MICHAEL VINCENT: Just as mobile phone apps now cause users to become obsessed, so too the crossword had a massive social effect in its day.



MERL REAGLE: Because everybody was solving them all the time, they put little dictionaries in the compartments on trains in LA, they limited the amount of time you could read the dictionary because so many people wanted to use the dictionary to solve puzzles. There were lots of divorces where the wife would say 'all he wants to do all day and all night is crossword puzzles'. There were shootings because people got fanatic about crossword solving. For some reason it was just this amazing thing that took over America in the 1920s.



MICHAEL VINCENT: And for a man who's made his living out of making crosswords, becoming so famous he's appeared on The Simpsons, Merl Reagle has his own theory as to the crossword's popularity.



MERL REAGLE: The reason I would think most people solve in the morning is because it's like a little mental test. It's like a thighmaster for your brain. On exams, either you know it or you don't, but a crossword, if you know one thing it helps you get the other things. So when people always say 'well, can you give me a hint?' That basic human question is answered by crossword puzzles.



MICHAEL VINCENT: To mark the 100th anniversary some US publications are challenging their readers to solve the original crossword.



This is Michael Vincent in Washington for AM.