Adjustable angle liquid prism with detachable glass prism by Ducretet et Lejeune of Paris, C. 1870 Adjustable angle liquid prism with detachable glass prism by Ducretet et Lejeune of Paris
"Univis" fused bifocals, nos.150-151.= 2 pairs rimless spectacles on small metal stands "Univis" fused bifocals