What are these Bausch and Lomb things?

[lewmel]

I picked up this set of what appear to be measuring glasses or something for a microscope.  The B & L symbol is on the case, but i do not know exactly what they are.
Any help?
Thanks

[KC]

These appear to be porro prisms......(often used in binoculars, scopes, etc).

[fancypants]

Look like 'blank' gauges to me .

Used for quick measurement/selection of optical glass 'blanks' (also for their dies) , prior to being machined in a lens generator (first step in the lens-grinding/machining process) .

Have you got a patent # , lewmel ?

[cogar]

I agree with KC and my guess is, that is a per say "salesman sample" box of prisms made by B&L and given to any manufacturer of optical equipment for design work.

Once a prototype was built and tested they could then order all their prisms from B&L.

[lewmel]

Thanks for the responses!
I picked these up at a yard sale, buying them not even knowing what they were.  But for the price I thought it may be a good ebay item.  Looks like I  have to research porro prisms!
Thanks again

[regularjoe2]

I'm curious about the numerals/markings on the case ...can't read them .

I'd suspect that they're in diopters , @ this point in time .

[lewmel]

Inside of the case the glass pieces are numbered 1 through 10, and then 12 14 16 18 20 30 40
On the glass pieces there is a small triangle next to the numbers.

[regularjoe2]

What you have there is a set of standard calibrated Prism Diopters (Abbr. - PD) .

A prism diopter is a unit of prismatic deviation that is used to describe a deflection of 1cm. at the distance of one meter .
The symbol for this unit is the small upright triangle you've described in your posting .

The higher the # of the gauge , the higher the deviation .

The set that you have can be , and is used , in a number of optical calibration applications - including but not limited to - experimental , educational , manufacturing , scientific & medical .