More tat for 20p at a car boot. About 20cm high, sits at 45 degree angle, mirror on bottom piece, clear lens at top so thought it was some kind of microscope but the lower glass of the top piece is opaque so you can’t see through it. No idea what it’s for, any ideas?

Periscope off a soviet sub, very rare, very valuable!!

It’s for inspecting thrunges.

If the bottom glass seems opaque, it might be for viewing eclipses and/or the sun.

BIG WARNING – Don’t test this out without confirming first!

I would guess the bottom piece is filtering out most of the light so you can then view via the mirror.

Although safer methods of viewing the sun would be reflecting on a paper surface. With this kind of gadget, any scratches on the opaque bit would be dangerous.

Could be something entirely different though.

It’s a quality control inspection instrument from a factory making Penne pasta.

If the bottom glass seems opaque, it might be for viewing eclipses and/or the sun.

That’s a good shout – the middle bit being a viewing area presumably.

Dunno, but full marks for the lawn.

NB, the design, assuming it’s for looking at the sun, may be to project the image onto something; NOT TO LOOK DIRECTLY INTO!

Refractometer

I was thinking refractometer but assumed op would mention a scale visible in the viewfinder if there was one

No scale on it, like the idea for pasta inspection

It’s for seeing what Scotsmen keep up their kilt

Enlarger focus finder – used to focus image from enlarger onto baseboard/paper .

Edit- probably Bestwell Magna Sight

Refractometers have a ground iluminating prism, but the viewing lenses are clear.

Is it ground (rough diffusing surface) or opaque (a colour in the glass)?

As above, definitely a focus finder for photographic printing. It’s angled so it can sit where the paper goes but you can still get your head above it with the enlarger above.

Cucumber holder

full marks for the lawn

Sorry but there’s just no **** way!

‘s gotta be a pub lawn what with that table n all.

finishthat – Member 
Enlarger focus finder – used to focus image from enlarger onto baseboard/paper .

Edit- probably Bestwell Magna Sight

Aha, yeah that seems to be it. So these are aka focus magnifiers or grain focusers? You use it when enlarging for print to magnify the grains on the photo to adjust the focus until they are sharp, which supposedly is more accurate than trying to focus the image by eye alone? If my Google research has it right. (never did darkroom stuff).

Yep, used to use one in the dark room, for getting sharp focus on grain.