He even offered $100 (a lot of money at that time!) to anyone who could come up with a set of handcuffs from which he couldn't escape. No one ever collected on that offer, though — Houdini could escape every time.
In 1912, Houdini introduced the Water Torture Cell, which would come to define his already spectacular career. In this spectacle, Houdini would be hung by his feet and lowered upside down into a locked glass container filled with water. He would have to hold his breath for more than three minutes while he tried to escape, which he did successfully every time.
He always stayed in top physical and mental health. To hold his breath for more than three minutes, he practiced at home regularly in an extra-large bathtub he had installed just for this purpose.
He also trained his left hand to work as well as his right hand, and he practiced many “tricks," such as learning how to tie and untie ropes with his feet. As for the handcuffs, he revealed that many times he could open them with force, although occasionally he used shoestrings and hidden lock picks and keys.
Although he was a magician at heart, Houdini never believed in the supernatural. In fact, he would often offer $10,000 (an enormous amount of money back then) to anyone who could come up with a psychic phenomenon that he couldn't duplicate by natural means. As usual, no one ever won that bet either…