Westinghouse industrial and commercial fluorescent lighting 1930 something
I would guess 1940 or so.
I could not find a date. code.
On one ballast there looks like a date of 1/5/39.
So It could be 1941.
Another ballast has a 3/3/41 date.
If it is a date.

Very detailed.
I like the ballast with the glow bulb type starter that plugs in to the end of the case.

There is shown a ballast for DC operation, that has a resistor and starter and what looks to be a choke.
How does a choke work on DC?
What am I missing here?
Oh I think I figured it out already.
It has to do with just the starting part only, not normal operation.
When lit up the DC don't see the choke only the resistor and the bulb of course.
I think.
I wonder how they figured this kind of stuff out back then?
I wonder how many blow ups they had before they got it right?

Nice fixtures here.
https://archive.org/details/FluorescentLightingForIndustrialAndCommercialApplications


Rest Glow lighting catalog.
There is a nice vertical hanging lamp shown.

https://archive.org/details/Rest-glowFluorescentLightingAndFixtures