19th century Brewster-type stereoscope

A remarkable item has landed the Gomez-Velasco camera collection: A 19th century Brewster-type stereoscope.

Stereoscopy (also called stereoscopics, or stereo imaging) is a technique for creating or enhancing the illusion of depth in an image by means of stereopsis for binocular vision.[2] The word stereoscopy derives from Greek στερεός (stereos) ‘firm, solid’, and σκοπέω (skopeō) ‘to look, to see’.[3][4] Any stereoscopic image is called a stereogram. Originally, stereogram referred to a pair of stereo images which could be viewed using a stereoscope.

Most stereoscopic methods present two offset images separately to the left and right eye of the viewer. These two-dimensional images are then combined in the brain to give the perception of 3D depth. This technique is distinguished from 3D displays that display an image in three full dimensions, allowing the observer to increase information about the 3-dimensional objects being displayed by head and eye movements.

Stereoscopy – Wikipedia

All the carved Brewster-type stereoscopes I have found. like this one, are from the 19th century.

The is a this 1870-1879 French Brewster-type stereoscope made in France, sold for a wopping US $712.45.

This other stereoscope is dated circa 1910. Sale price: £189.00

Below is the closest model I have been able to find. This one has slightly sharper edges and the woodwork and engravings are different, but the general shape, mirror hatch, and eyepieces are almost identical:

This instrument is a trapezoidal-shaped box with curved edges made from mahogany for viewing pictures in 3 dimensions. In front, two converging lens eyepieces adjusted for focal length with rack and pinion mechanism.

The whole supported on a brass-telescoping pillar with black painted tripod feet. On the opposite side of the lenses, two lateral openings for the insertion of stereoscopic pictures on cardboard or tissue and a sheet of frosted glass to diffuse the light through the tissue picture.

On top, a hinged mirrored door that acts to reflect light for frontal illumination of cardboard pictures The mirror is in poor condition. Internally, the box is darkened and is divided into two parts with a center partition that prevents each eye from perceiving the image of the other.

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.

Brewster Stereoscope Mahogany 19th Century ($500!)