mysterysolved

Looks like an early durometer - drops a ball onto a piece of material with high precision??.

www.gardco.com/pages/hardness/OSoperatingstands.cfm shows examples modern examples of what KenjiB_48 has in mind.

The fact that they're dressed like dentists seems like a clue. Look at the high resolution TIFF and the gadget certainly may be a glass X-ray tube. The golf ball is sitting on a packet wrapped in opaque paper—so my guess is that there's a film or a plate wrapped inside it to record an image of the golf ball innards.

Miller-Urey experiment?

Scarsdale Inquirer, Number 36, 2 August 1924 news.hrvh.org/veridian/cgi-bin/senylrc?a=d&d=scarsdal... notes, among many applications of X-rays, use for checking that the core of a golf ball is dead centered. New Smyrna Daily News from New Smyrna, Florida · May 2, 1924, Page 3 www.newspapers.com/newspage/15302976/ mentions such use. www.golfwrx.com/247385/inside-titleists-golf-ball-facilit... suggests that it was a few years later (early 1930s) that Titleist started using X-rays in the production line.

Some obscure orchestral noisemaker?

The pensive guy is holding a small slab of marble, or some other veined stone. It looks like the big wheel is designed to clamp a whole series of slabs of the same size into a rotating jig. In the high-res view you can see the slabs are a few different varieties of stone. It's a little hard to see what those roller-like things underneath are doing; but perhaps there's a spinning drum to grind or polish the surfaces of the slabs.

Perhaps someone was testing and comparing types of stone for abrasion-resistance. Selecting which one to use for stair treads in public buildings?

The slabs look mostly like marble (which is not a great choice for stairs btw.) Nonetheless, perhaps they wanted to find the hardest batches. Maybe one of the rollers underneath is in fact some kind of abrasion tester. Floors could be another application.

A Bureau of Standards publication from 1933 is titled Wear Resistance of Natural Stone Flooring nvlpubs.nist.gov/nistpubs/jres/11/jresv11n5p635_A2b.pdf A quick skim suggests this report shows and describes different equipment and tests but does confirm that the agency did related work.

Looks like it meant to take a 360-degree photograph.... actually 8 photographs of 8 mirrors.

The lenses are 6-inch wide angle "Xpres" lenses made by Ross (based in London, UK).

this was actually the first iteration of Daleks for the 1914 stage play "Dr Who"

related to www.loc.gov/pictures/item/hec2013011206/resource/ I think this is the same camera, seen from the other side.

The most similar thing I have found is in www.isprs.org/proceedings/XXXIV/5-W16/papers/PanoWS_Dresd... See fig 20 for an aerial panorama camera.