On Tue, 6 Aug 2019 09:26:38 -0500, dpb wrote:

On 8/5/2019 3:42 PM, Clare Snyder wrote:
On Mon, 5 Aug 2019 11:18:22 -0500, dpb wrote:

On 8/5/2019 8:08 AM, Bill Gill wrote:
...

You'll have to work at plugging a 2 prong plug in backward.
The prongs are 2 different widths, so the plug will only
go in one way.
...

That's also a (relatively) recent evolution in the history of the
electric toaster...
I had onwe from the late 40s with a polarized plug - so old it wasn't
a "pop-up"

Nothing prevented them from using the plug; was it the wide blade type
like current? I'm not sure when the polarized receptacle actually was
introduced but it wasn't until sometime in 60s it became required...


Although polarized outlets and plugs were introduced in the 1880s,
they were not popular at first and did not become standard until the
mid-20th century. The earliest National Electric Code (NEC) that we
can find that references polarized receptacles is the 1962 edition,
which required outlets to be both grounding (3-prong) and polarized.