1851
Steroscopy
David Brewster

"Almost overnight a 3D industry developed and 250,000 stereoscopes were produced and a great number of stereoviews, stereo cards, stereo pairs or stereographs were sold in a short time. Stereographers were sent throughout the world to capture views for the new medium and feed the demand for 3D images."

Sue Davies, History of 3D Photography and Anaglyphs

Even if the first stereoscope was not conceived by the British scientist David Brewster, but by the British mathematician Elliot in 1823, who also constructed the first device in 1939, it was Brewster who proposed to use glass lenses that were manufactured by the French instrument maker and pioneer photographer Jules Duboscq in France allowing the devices to become smaller and handier. The overnight success of the lenticular, or lens-based stereoscope, thus also known as "Brewster stereoscope" followed the presentation of the device at the Great Exhibition in London in 1851. The time period between 1860-1930 is described by Sue Davies as the golden age of stereoscopy.