WW: Century-old wiring

(This ancient outbuilding, one of a few derelict structures still surviving from what was a working dairy farm near my home when I was a child, has knob-and-tube wiring. As you can see, it was a two-element system consisting of cloth-covered wires strung on insulators. In living areas they were usually hidden inside walls, but in basements, attics, service buildings, and outdoor applications, they were hung along rafters, down siding, and under eaves, as here. [Note the old-school porcelain insulators – no longer wired – on the rafters.]

Though alarmingly primitive to modern eyes, knob and tube wasn't much more dangerous than recent methods. The main reason it disappeared was that it required twice as much labour as the single integrated cable introduced in the 50s, and was therefore twice as expensive to instal.

I believe that old farm dated to the 20s [the other 20s, I mean], when knob and tube was industry standard. But this shed was apparently still rocking it in the 70s, while in active commercial service.)

Appearing also on My Corner of the World.