What does this OLD power cord go to?

[electrofro]

I won a bunch of stuff in an auction and I was digging through it all and came across this old power cord. The auction also had a bunch of old test equipment (which I didn't win) and I was thinking maybe it goes to one of those. Does anyone recognize it? Or can someone possibly point me in a direction I can search? Thanks!

 

[dorke]

Welcome to EP,
Looks like something from Edison's Lab

 

[ChosunOne]

Welcome to EP,
Looks like something from Edison's Lab

No, that's an AC plug and Edison would only use DC.

 

[73's de Edd]

I remember them from old toasters from the '20's, until they came out with the familiar tandem plug.
If you ran off batches of toast, you could eventually catch the slight aroma of bakelite from the toaster end.