Under flintlock and key: 17th Century jailer's guns give new meaning to being 'banged up'
An absolutely fascinating gallery of photos of ‘Jailer’s keys’ “Jailers’ keys were apparently filled with gun powder to create a primitive gun that could be detonated if there was any trouble when opening a cell door. We found several original versions that back up this claim, dating from the 17th century and of various complexity.”