Brass projection lens - edge markng

[Fotoguy20d]

I was cleaning the glass on a large brass projection petzval and the lfront and thicker rear element are marked on the edge with CG and a 4 digit number. Any idea who made it?

Thanks,
Dan

[Steven Tribe]

Clement & Gilmer.

This optical house claimed to be a continuation from Gasc & Charconnet ( founded in 1860 ) from 1887. They then became Laverne in 1890.

Writing the producers name on the lens edge is very much a French thing! In other countries it was mostly reference numbers and artisans/qc names.

[Fotoguy20d]

Steven,

Thanks! The barrel is in fact marked France. I've seen several Darlot lenses edge marked in this way. My first thought on seeing the marking was G&C but after I looked again at the ordering of the letters I decided that wasn't right.

Dan