Brass lens - where does the spacer go?

[ajmiller]

A few years back we found this lens in my French wife's family house when clearing it out to sell. It came from a magic lantern as I recall but can't be sure. It was in bits and I collected all I could find and put it together as best I thought. I wouldn't mind having a go with it now and want to confirm the correct placement of the glass and the spacer. I found this description from 'goamules' https://www.largeformatphotography.i...=1#post1121784
and wondered if this is the way to go with mine?
Thanks for any help.
001 by Tony Miller, on Flickr
003 by Tony Miller, on Flickr
004 by Tony Miller, on Flickr
005 by Tony Miller, on Flickr

[MartyNL]

Hi Tony, Hopefully, all of the pieces are there. I think there is a great probability that the lens is either a Petzval or Triplet design. Please, see images.
The spacer will go between the two closely spaced lens cells, accordingly.

It sounds like a wonder project and it would great to see the results.

[Steven Tribe]

This is perhaps a better drawing. Note the greatest curvature on the double convex lens points towards concave surface - with the spacer between them. The Waterhouse slot has been home cut in a plain projection apparatus.
There is more here https://antiquecameras.net/petzvallens/oldarticle.html.

[ajmiller]

Thanks for the replies Now to sorting the stops out. A friend did make some wooden ones a few years ago but I think the ridge for the rack and pinion was an obstacle in getting a good fit (though I’m unsure that’s a major issue?). All good fun!