Foldable Stereoscope ‘Le Merveilleux’ with original storage box

The stere­o­scope con­sists of a wood­en box. The lid con­tains a wood­en block with grooves into which a stereo card can be insert­ed. When the lid is slid open, the lens pan­el can be unfold­ed. The focus is adjust­ed by slid­ing the lid, which changes the dis­tance between the lens­es and the stere­oview. The two square lens­es are sur­round­ed by met­al frames that serve a dec­o­ra­tive pur­pose only.
(from: Com­pendi­um of Stereoscopes)