They Invented it When?

One of the earliest types of locks, first found in the Near East and dating from about 2000 B.C., was little more than a wooden bolt with some holes drilled into it. When the bolt slid into place, pins on the door dropped into the holes and held it in place; the key was another piece of wood with the same pattern of pegs, which lifted the pins when inserted. The technology didn't improve much until 1778, when Robert Barron conceived of the lever-tumbler lock. A series of levers in the lock had holes at varying heights. Only a key with the right pattern of ridges could line up all the levers and allow the bolt to move, but the lock was easy to pick. In 1784, Joseph Bramah invented a nearly unpickable device, but it was so intricate it could not be mass-produced. Linus Yale Jr. finally hit on a winning combination when he patented his pin-tumbler lock in 1861 and 1865. Like the ancient Middle Eastern lock, his lock uses a series of pins, but it contains them within a cylinder held in place by spring-loaded driver pins. When the key is fully inserted, serrations on the top edge lift all the pins to the correct height and let the cylinder turn. A groove cut into the side permits more kinds of keys, further enhancing security. Next up: computers that read fingerprints or iris patterns will act as "smart keys," opening locks only for authorized individuals.