An early stereoview like those produced by Louis-Jules Duboscq to demonstrate his version of the Brewster viewer. In 1851 Duboscq released a set of 40 white-on-black views of simple hand-drawn geometries that became known as the Parisian Set. These are a later copy—views from the actual Parisian Set were blue on the back and numbered on the front. Most of the geometries in the Parisian set were such that left and right views could be created simply by flipping the drawing horizontally