Foldable book stereoscope

Lit­tle is known about Adolphe Teis­son­nière. On 16 April 1864, he filed two patents: one for a book stere­o­scope, the oth­er for a chro­mat­ic reflec­tor which, when used with a stere­o­scope, could col­or the images to pro­duce var­i­ous effects. His com­pa­ny, A.T. & Cie, short for Adolphe Teis­son­nière & Cie, pub­lished his inven­tions. The intro­duc­tion to his patent below per­fect­ly describes his invention:
My inven­tion con­sists of a new type of stere­o­scope, called a book stere­o­scope or brochure stere­o­scope, imi­tat­ing every­thing from a brochure to a book with the most lux­u­ri­ous bind­ing, open­ing instant­ly and auto­mat­i­cal­ly when the book is opened, hav­ing short-focus lens­es that mag­ni­fy the images and, if desired, chro­mat­ic reflec­tors that col­or the images by reflec­tion (patent­ed by me on this day).
Var­i­ous ver­sions of the book stere­o­scope are known, with cov­ers of vary­ing degrees of lux­u­ry, as well as a ver­sion housed in a wood­en case.
(from: Moulin­ier et al. His­toires de vision­neuses stéréo­scopiques français­es. Limo­ges, 2025, p. 229. Author’s translation.)