Wheatstone stereoscope
The Wheatstone stereoscope was named after its inventor Sir Charles Wheatstone who devised the earliest type of stereoscope in 1832, which was prior to the advent of photography. It is a reflecting mirrored stereoscope in which a set of images (which need to be reversed) are placed facing each other at both ends of a horizontal bar and then they are viewed through a set of angled mirrors which are attached midway between them both.
Window
A stereo window refers to the screen surround unless floating windows are being used.