A Blast from the Past

 On a practical level, lookie what an electrician friend saved for me a few years back when he and crew re-wired my place.  An extremely vintage electric power meter:

Zooming in on the brass label shows that it could handle 5 amps at 100 vac.  Quick math... carry the -i... excuse me, that'd be -j...  Why, that's just about enough power to light five incandescent bulbs.  Capacity and consumer expectations have changed somewhat since its 1921 manufacture date.  Take a quick look inside:

It's so clean that it looks like it could function today.  There's a little corrosion on the back of the aluminum dial plate that has caused it to curl forward slightly so that it touches the dials, so they'd scrape at the 12 and 6 o'clock positions, and no doubt all of the wiring insulation is bad.  As for the rest, even the brass is bright and shiny.

It's a keeper, for sure.  Not quite sure what to do with it yet, but something will come to mind.  (no, "hook the damned thing up and see what happens" is not in that possibility set)  In any event, a little minor exterior cleanup will be the first order of business.

I wonder when household AC voltage changed from 100 to 110?  Couldn't quickly find this with a conventional search, so let's see what an AI can dig up.  From grok.com:

Q: When did household wiring voltage change from 100 vac to 110 vac in the united states? 

In the United States, the transition from 100 VAC to 110 VAC for household wiring voltage occurred gradually in the early 20th century, with no single definitive date. The shift was driven by the standardization of electrical systems and improvements in power distribution.

• Early 1900s: Many early electrical systems in the U.S. operated at around 100–110 VAC, with local variations. Edison’s early DC systems and early AC systems often targeted 100–110 V for incandescent lighting.
• 1920s–1930s: As the electrical grid expanded, utilities began standardizing on 110 VAC (or slightly higher, like 115 V) to improve efficiency and reduce transmission losses. The National Electrical Manufacturers Association (NEMA) and other bodies pushed for standardization.
• Post-WWII (1940s–1950s): By this time, 110–120 VAC became the de facto standard for household wiring, with 120 V eventually becoming the nominal standard in modern systems. The transition was complete in most areas by the 1950s.

Exact dates varied by region and utility company, as upgrades depended on local infrastructure. If you need specifics for a particular area, I can try searching for more localized information.

Well there we have it, at least as much as we're ever going to get an answer.

I have no earthly idea of how to classify this post, so I'll leave the tag it with the usual inner coyote.  And no, I'm not going to hook this thing up to power, ever.