Handheld Brewster stereoscope. This instrument is a trapezoidal-shaped box with curved edges made from mahogany and walnut veneer. In front, two large converging lens eyepieces adjust for focal length with rack and pinion mechanism. Knob is made with black bois durci. On top, a hinged mirrored door reflects light for illumination of the stereoscope slides.
Sir David Brewster (1781-1868) was a Scottish physicist who invented the kaleidoscope and this reflected light lens stereoscope. He also discovered the polarization phenomenon of reflected light.
Has been repaired on edges. The mirror is in good condition.
It measures 4 1/2 H x 7 3/4 W x 5 3/4" D and weighs 1 lb. 8 1/4 oz.