Brass lens/No.1 Hemispherique Rapide

I just got a lens that I know nothing about--just curious if anyone knows much about this lens. It is marked: No.1 Hemispherique Rapide 5704. I'm not really sure if it even has all the bits and pieces! It has a slot for dropping in apertures (at least I think that's whit it's for) and the tube has threads on the end, so it may be missing something. Anyway, any info or links to websites with more info would be much appreciated! I'll try to post some photos of it...

Thanks,
Matt

c. 1880-1900

Rapid Rectlinear lens in 4x5 size. Value if complete $ 150-200

Dan

Cool, thanks. Mine is missing the mounting piece. Oh well, it was free! I'm sure I can find some use for it.