Conversation so far:
What was the Mirror challenge for Harry Houdini?
In 1904, the London Daily Mirror newspaper challenged Harry Houdini to escape from special handcuffs that it claimed had taken Nathaniel Hart, a locksmith from Birmingham, five years to make.
Who challenged Harry Houdini to escape from special handcuffs in 1904?
The London Daily Mirror newspaper challenged Harry Houdini to escape from special handcuffs that it claimed had taken Nathaniel Hart, a locksmith from Birmingham, five years to make.

Question: Who was Nathaniel Hart?
Self-contained rewrite: Who was Nathaniel Hart?