Invented by Théophile Eugène Lacroix, the Théoscope is a home cinema dating back to the turn of the 20th century, enabling one to watch short animated scenes. It is built out of a simple wooden case, equipped with an eyepiece and a crank. Inside, several hundred (320 in this precise case) 35-mm paper images are hung from a link chain, the rotation of which causes the procession of the images in front of the eyepiece. Set in movement, the mechanism stops the images one by one, perfectly flat under the eyepiece. Thus, the viewer can choose the desired speed of the projection of the images, and thus of the little film he's watching.

The Théoscope falls within the lineage of certain pre-motion-picture apparatuses and optical toys, which had announced the birth of the cinematograph. For example, like the Praxinoscope Théâtre, which Emile Reynaud (1844-1918) constructed in 1879, it is based on the reconstruction of a movement resulting from a succession of images, drawn in the case of the Praxinoscope. The human eye has, in point of fact, the capacity to retain perception of a seen image, and superimpose it over the one that it is seeing: this is known as retinal persistence, which generates the illusion of movement.

Before the birth of the motion pictures, there thus already existed many apparatuses permitting the reconstruction of a movement, which could be watched in a loop. But at the turn of the century, the Théoscope uses images that were filmed with a cinematograph, then transferred onto paper, and sold in bands. To the individual and family aspect of optical toys must be added the step of live-image recording, and the utilisation of images of reality! If it is more cumbersome, the Kinetoscope of Thomas Edison (1847-1931) also allows one to watch a film contained in a tall wooden box, whose filmstrip loops under the eyepiece.

Today, the Théoscope is a very rare instrument. There is only one copy conserved in Rome, another one in the United States, as well as three in private collections. These images, restored by Cineteca Nazionale, in Rome, have remained hidden for more than a century! They mark nevertheless the beginnings of a common family practice: watching a film, at home.