AMUSEMENTS IN MATHEMATICS

by HENRY ERNEST DUDENEY, 1917

UNCLASSIFIED PROBLEMS.

417. — THE TIRING IRONS.

The illustration represents one of the most ancient of all mechanical puzzles. Its origin is unknown. Cardan, the mathematician, wrote about it in 1550, and Wallis in 1693; while it is said still to be found in obscure English villages (sometimes deposited in strange places, such as a church belfry), made of iron, and appropriately called “tiring irons”, and to be used by the Norwegians to-day as a lock for boxes and bags. In the toyshops it is sometimes called the “Chinese rings”, though there seems to be no authority for the description, and it more frequently goes by the unsatisfactory name of “the puzzling rings”. The French call it “Baguenaudier”.