Electrical outlet types - photo

[WmRMeyers]

Don't know what type this would be called, but it is a DC outlet in the floor of a room at Biltmore Estates in Asheville, NC. Part of the original electrical system. One of the first private homes with its own self-contained power station. Early 1900's

'Obsolete' is what they'd be called now!

Somewhere, there has to be an old electrical catalog where they have them listed.

Bill