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Antiques! => Antique Questions Forum => Topic started by: lewmel on September 18, 2009, 12:48:45 PM

Title: What are these Bausch and Lomb things?
Post by: lewmel on September 18, 2009, 12:48:45 PM

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

Title: Re: What are these Bausch and Lomb things?
Post by: KC on September 18, 2009, 10:42:50 PM

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

Title: Re: What are these Bausch and Lomb things?
Post by: fancypants on September 18, 2009, 11:15:22 PM

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 ?

Title: Re: What are these Bausch and Lomb things?
Post by: cogar on September 19, 2009, 03:20:55 AM

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.

Title: Re: What are these Bausch and Lomb things?
Post by: lewmel on September 19, 2009, 07:00:23 AM

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

Title: Re: What are these Bausch and Lomb things?
Post by: regularjoe2 on September 19, 2009, 08:50:23 AM

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 .

Title: Re: What are these Bausch and Lomb things?
Post by: lewmel on September 20, 2009, 06:57:49 PM

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.

Title: Re: What are these Bausch and Lomb things?
Post by: regularjoe2 on September 20, 2009, 07:53:22 PM

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 .