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I cant have been drawing *much* more than 10 amps. The PSU was a metal caged monster in one corner of the room good for something like 250A Individual outlets had IIRC 2 strands of 5A fuse wire in the fuse holder for protection. We *might* have put a third one in, I cant remember.
The choke lived on a trolly and got pushed around the lab to where it was needed. Looked like it was a hand wound core of what I now know was soft iron wire with a black wooden terminal board, black tarry fabric insulation, ceramic insulating washers and brass terminals and a little engraved plaque that was probably ivory giving its ratings, some instrument maker's name and a date sometime back in the 1890's. It was basically square, about three foot across the case and over a foot deep with wooden top and base boards joined by some sort of cast brackets at the corners and open sides you could see two monster bobbins through with a bound wire core. If its still in existence 30 years later, it belongs in a museum, in fact it belonged there at the time . . .
The contact on the wire was near the tip of the pencil. If you have hefty supply carefully carve a notch down to the lead about an inch back from the tip and wrap a good few turns of fusewire round the half exposed lead and the wire you are connecting it to. That reduces the burnup problem some. Use a 5B pencil nicked from the Art department if you can, the purer thicker graphite worked *much* better ;-)
IIRC we sooted the lenses of some safety glasses we'd liberated. I would have warned you if I thought you were curious enough to try it!
As you may have gathered, this experiment was strictly sub rosa and never appeared on the curriculum.
Watch out, that choke would deliver a kick like mule if you broke the the arc and were'nt *bloody* careful what you were touching. *DONT* get yourself in circuit!