In the 1770s, master locksmith Joseph Bramah made quite a few improvements to the security of locks. He was so confident in his inventions that he issued a challenge, written on the lock above: “The artist who can make an instrument that will pick or open this lock shall receive 200 Guineas the moment it is produced.” Another locksmith named Jeremiah Chubb issued a challenge with his own lock, featuring his own innovations. Those two challenges stood against every attempt for a long time -until The Great Exhibition of 1851 in London.
One of the attendees was A. C. Hobbs, an American locksmith. Back in the states, Hobbs had made a name for himself by showing bank managers that their locks could be easily picked, and convincing them to buy one of his. Hobbs was selling lots of locks this way.
On day one of the exhibition, Hobbs publicly announced that he would pick the Chubb detector lock—the one that stops working if you pick it incorrectly.