Brett Duran, age 9, of Greenville, Miss., for his question: _
WHEN WAS THE LOCK AND KEY INVENTED?
The need for a device to protect people and property from unwelcome intruders is as old as mankind. As a matter of fact, primitive man probably made the first lock when he rolled a boulder in front of the entrance to his cave.
Today's lock and key was developed from a crude wooden device that the Egyptians invented 4,000 years ago. The Egyptian lock, invented around 2000 B.C., was the first device that was a true key operated lock. It consisted of a large wooden bolt operated by a big wooden key that looked like an oversized toothbrush.
This lock was fastened to the outside of a gate. It had pins, or pegs, that fell by gravity into holes in the bolt. The pins then prevented the bolt from being moved until they were lifted from the holes. This was done by inserting the key.
The key had wooden pegs on the end that lifted the pins out of the holes in the bolt so that the bolt could be moved and the gate opened.
The next contribution to lock development came with the ancient Greeks, who were the first to fasten the bolt inside of a door that could still be moved from the outside. They did this by devising a huge key shaped like a sickle that they inserted from the outside through a hole in the door.
The shape of the key made it possible to engage the bolt on the inside and slide it back. The unwieldy key was a major disadvantage of the Greek lock. The Greek lock was described by the Greek poet Homer in the 700s B.C.
The technically minded Romans reapplied the Egyptian pin principle but they made their pins in widely varying geometric shapes. The use of variations in pin shape profiles increased security by making it less likely that the key for one lock would open any door.
Roman locks were much smaller than those developed by earlier peoples. The Romans also came up with an improvement on the Egyptian design that incorporated.springs in their locks to press the pins into the bolt, rather than depend on gravity.
Later, the Romans invented warded locks. They served as the most frequently used security devices until the middle of the 1800s and many are still in use.
Their mechanism contains a series of obstacles, or "wards," which the key must pass in order for the bolt to be retracted. Thus the key bit, which is the part of the key that enters the lock, must be cut to correspond with a particular set of wards.
After these developments, no basic change in lock design occured for many centuries.
During this period, alarm and trapping devices were incorporated into locks, keyholes were hidden under ornamentation and wards became more intricate. But no major changes in the protective capabilities of locks occurred.