††The mass-production of locks did not occur until a United States locksmith, Linus Yale Jr, patented his barrel and pin mechanism in 1865. This type of lock is still popular today. Security measures have had to increase as the burglar has learned to overcome most types of lock. More secure modern locks include the combination lock, where a dial mechanism must be turned a certain distance backwards and forwards to open, and time locks, which are set to be opened only at specific times.
