The Evolution of the Lock

By Lindsay Tucker | Boston Magazine |

FOR JUST ABOUT AS LONG as we humans have had things to call our own, we’ve had the locks with which to shut them away from everybody else. And after a couple millennia of this, the variety of systems that we’ve innovated, discarded and reimagined border on the countless. Now, in honor of our recent profile of master lock picker Schuyler Towne, we take a look at some of the more defining moments in the evolution of the lock:

1. Ancient Egyptian Pin Tumbler   The Egyptians, as is often the case, were way ahead of the game when it came to their locks. Back around 2000 B.C., they invented what remains the dominant concept in today’s residential locks: the pin tumbler lock. The Egyptian tumbler was one of the first to use a key, and featured a wooden casing containing several loose pegs of varying length — pins, as they’re called now. When loose, the pins kept a bolt in place, locking the door. The right key lined these pins up evenly, permitting the bolt to be opened. The only major difference between this lock and that on your own house? The keys were more of than not more than a foot long and resembled oversized toothbrushes — the longer the key hole the less likely the pins could be manipulated by a picker. 

2. Gordian Knot    Unlike the Egyptians, the Ancient Greeks are known not for a lock-and-key system, but for their knots — specifically, the Gordian knot. As legend has it, a Greek peasant named Gordius strolled into the town square of Phrygia with nothing to his name but a small oxcart and his wife — precisely the manner, as it so happened, as an oracle had told the people of Phrygia their the king would arrive. So king he became. Filled with gratitude, newly-promoted Gordius dedicated his oxcart to Zeus, tying it up with the unusual knot that would become known as the Gordian knot.

3. Living Locks   The locking mechanisms of the Medieval period lacked the sophistication of the Egyptian locks, though they compensated for this with sheer brute force. Valuables were sealed into large wooden boxes and placed on small islands or submerged in pools where they were protected by hungry crocodiles, and many estates were similarly protected by moats. Stephen Tchudi, author of Lock & Key: The secrets of locking things up, in, and out, calls these guard crocs “living locks.” “A lock, after all,” he says, “is simply a barrier or closure, a way of sealing up an entryway, of keeping what you want in, in, what you want out, out.” Those desperate enough to try lock picking had no choice but to drug or kill the croc — pretty risky for a petty larceny.

4. Latchstring Locks   Invented by prehistoric man and perfected in Colonial America, the latchstring came to prominence in the American west. One of the first “keys” used in America, it operated on a very simple premise: a string was hung outside of the door, through a small hole near the door handle. Pulling the string lifted a bow behind the door, allowing it to open. Those who came calling knew the dangling string as a sign of welcome, and eventually someone coined the phrase "the latch string is always out." Mind you, the system was nearly impossible to lock from the outside, but some inventive settlers took to hiding the latchstring by threading it out through a second hole placed along the house but away from the door and bow.