This solved the biggest problem in handcuff work: accessibility. The inner belt ran on tiny ball bearings that could be revolved by pressure from Houdini's arm. As his skills and popularity grew, Houdini invented and used a belt made of flexible steel, containing special compartments within a double wall. At the beginning of his career, Houdini would simply conceal the keys in secret pockets or a bag strapped to his leg. It was as 'The King of Handcuffs' that Houdini first came into fame during the early years of the twentieth century. Concealing keys was simple when presenting a normal stage act as time would often not allow for an exhaustive search. When entering a new town, the magician would research the handcuffs used by the local police as well as any 'special' handcuffs and conceal the keys somewhere on his person. Having the full set of 45 keys would allow traveling magicians the most success.

According to NEW IDEAS IN MAGIC, published in 1902, the secret to a successful handcuff act is having multiple sets of keys. Magicians began to demonstrate handcuff acts as early as the 1890s.

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