When I was growing up I remember hearing stories about boys taking apart computers and putting them back together to see how they worked.

In my memory it was always said in a kind of whispered awe: these young geniuses with their irrepressible, adventuring minds.

I have thought about this often, the adulation of boys and men who do things that seem tricky, as I take apart and mend locks, power tools, lamps. What I know now is: these things are not that tricky. They are some of the most straightforward puzzles you can encounter in the built world. It's about finding the connection between structure and function, figuring out where something needs to go to do the thing you imagine it must do. There are some lessons in there, of course - a broad one about how social hierarchies are reliant on concealment (do you know what a management consultant does? how about a plumber?), and a narrower one about the power of necessity to make us do things we thought we could not.

Anyway: here's the original front door lock which I rehabbed and slotted right back in. And another date, which gives us an earliest possible construction year of 1883. Very likely it was a lock design that was used for some number of years after 1883, so it cannot reliably tell us more than that. If there are any lock experts out there...