IMPORTERS BOSTON Brass Magic Lantern Petzval lens, circa 1800's. Will need dissembling and lots of cleaning as can be expected. Some info on this lens according to web searching, was that it was made in Boston at 26 Bromfield St. Boston, Mass, and that it is a Petzval lens. The Petzval lens was developed in 1840 by Joseph Petzval.
It consisted of two doublet lenses with an aperture stop in between. The front lens is well corrected for spherical aberrations but introduces coma.
The second doublet corrects for this and the position of the stop corrects most of the astigmatism....
