Unidentified photographer / artist
1879 (after)
Nickel plated stereoscope by PATTBERG with a patent date of April 29, 1879.

Stereoscope
Stereographica - Antique Photographica
Courtesy of Bryan and Page Ginns (#18 / 20)
 
It is designed to be used for stereo views and as a graphoscope for cabinet cards. There is a bracket on the bottom of the stand to accommodate the hood or magnifying glass when not in use.
 
LL/21559