I don't think I have seen a fixture like this before.
http://www.ebay.com/itm/Vtg-industrial-fluorescent-lamp-vintage-factory-light-round-unique-steampunk-/251559278867?pt=LH_DefaultDomain_0&hash=item3a9219f913It would be a nice one if cleaned up and restored.
I would say it was designed for exterior lighting.
It also looks like it has a old GE daylight bulb.

A real nice later fixture with nice GE bulbs.
Interesting ballast and starter location.
I am not in to chrome fixtures though.
http://www.ebay.com/itm/Vintage-Mid-Century-Modern-Art-Deco-Fluorescent-Ceiling-Wall-Light-Fixture-/251562479997Here is the style I like.
It just needs some TLC to be brought back to new condition.
http://www.ebay.com/itm/Vintage-Art-Deco-Fluorescent-Metal-Ceiling-Wall-Light-Fixture-Glass-End-Caps-/261508862698This is interesting.
http://www.ebay.com/itm/Art-Deco-Table-Lamp-Night-Stand-Fluorescent-Bed-Eureka-Tea-Company-Pink-/271512813828?pt=Antiques_Decorative_Arts&hash=item3f376cc104Something I have found distressing is that some sellers of old lighting fixtures have been replacing the old bulbs with new ones thinking it makes the fixture worth more.

A little newer....
A Durastar street light.
http://www.ebay.com/itm/VINTAGE-INDUSTRIAL-DURASTAR-AEL-AMERICAN-ELECTRIC-STREET-LAMP-LIGHT-LUMINAIRE-/261504909872?pt=LH_DefaultDomain_0&hash=item3ce2e84230A NOS 96 inch PG fixture.
http://www.ebay.com/itm/Lithonia-2-lamp-8-fluorescent-T12-lamp-fixture-/191199170409?pt=LH_DefaultDomain_0&hash=item2c845bcf69Some bulb testing by Westinghouse 1/27/1950.
There are those three bulb fixtures overhead.
So they must have been designed before 1/27/50.
I would guess they had the three bulb ballast.
Unless they were the three phase fixtures.
Both GE and Westinghouse made three bulb three phase fixtures for use around rotating machinery, but I have never seen one.
Looks like some 100 watt T17s on the test board.
Check out the big ballasts on the table.
The ballast next to the scope looks like it has screw terminals on the end.
I think this was back in the days when the ballast was expected to last longer than the bulbs.

Looks like a new scope and don't even have the probes connected up yet.
Also I see some of those special large retangle plugs for asbestos covered cords used on early stage lighting.
http://www.ebay.com/itm/1950-Press-Photo-Kent-Stockton-of-fluorescent-test-laboratory-at-Westinghouse-/351079481883?pt=Art_Photo_Images&hash=item51bdf7c21b