Mortise & Tension

The door hardware upstairs comes in two styles: old and older. The merely old ones are called mortise locks because they're mortised into the door, meaning you cut a hollow pocket into the wood to accept the hardware. Then the entire lock mechanism slips into the pocket, completely contained inside the door. Hardly anybody does mortise locks anymore, and I can see why.

The really old locks, however, sit on the outside of the door. They're called rim locks and they're also square boxes like the mortise locks, but they don't go inside; they get screwed to the outside. Internally, both mechanism work the same. They even look pretty similar sitting on the workbench. The major giveaway is the decorative brass end plate on the mortise locks.

The mortised locks have smooth sides designed to fit snugly inside the door pocket, but with a pretty decorative end plate that you can see when it's installed. These were all coated with several decades' worth of paint, but once they're cleaned up they look pretty nice.

Some of the end plates are definitely prettier than others. You can also see the deadbolt that sticks out just below the angled spring latch. We don't have keys for these anymore, but they can't be all that hard to find. I've taken the mechanisms apart, and they're not complicated locks. I suspect one basic key would work on all of them. (For you locksmithing nerds, it's a lever lock, not a warded lock.) It relies mostly on gravity to make it work. Don't install it upside-down or you'll lock yourself in!

Our rim locks mount to the outside of the door. They're more utilitarian and less decorative. They have a thumb latch at the top that locks the mechanism and prevents the doorknob from turning. It's not as secure as the deadbolt, but these are just interior doors anyway. I don't think anyone's going to break into (or out of) the bathroom.

On the other hand, because these locks are mounted to the exterior of the door and not hidden inside, the manufacturer dressed them up a little bit. Here's a closeup of the one in my room. You can see it says, "PAT'D JULY 21 1865 B.L.W."

Presumably BLW is the manufacturer. And just because it was patented in 1865 -- Civil War era -- doesn't mean it was made in that year, but it's clearly very old. Probably original to the house, which was built in 1893. We've got three like this upstairs, plus two of the mortise locks.