Early Stereoscopy

This device was designed to look at early 3D pictures. The technology may have moved on, but the illusion remains the same. These pictures probably date from the late 19th Century or early 20th Century. The one in the viewer is of the Avenue de l'Opera in Paris and the other is of the Place de la Concorde. The Eiffel Tower is in view and so this dates it past 1889.
The lack of cars is striking and it must have been incredible for people to see what foreign lands were like.